புவி (), கதிரவனிலிருந்து மூன்றாவதாக உள்ள கோள். விட்டம், நிறை மற்றும் அடர்த்தி கொண்டு ஒப்பிடுகையில் சூரிய மண்டலத்தில் உள்ள மிகப் பெரிய உட் கோள்களில் புவியும் ஒன்று. இதனை உலகம், நீலக்கோள் ,நீலக்கோள் என்பது பல படங்களின் பெயராக Blue Planet மற்றும் The Blue Planet என பயன்படுத்தப்பட்டுள்ளது, லைப் (பத்திரிக்கை) (Life) என்பதன் நம்பமுடியாத ஆண்டு '68 (The Incredible Year '68) என்ற இதழில் புவி உதயத்தின் படத்தை போடும் போது ஜேம்ஸ் டிக்கே என்ற கவியின் வரிகளாக Behold. The blue planet steeped in its dream/Of reality என குறிப்பிடப்பட்டுள்ளது http://yalepress.yale.edu/yupbooks/excerpts/poole_earthri. e.pdf பக்கம் 7-8 http://www.northjersey.com/entertainment/books/36520714.html மற்றும் ஐரோப்பிய விண்வெளி முகாமின் அறிக்கையின் தலைப்பாக 'நீலக் கோளத்தின்' நீர் சுழற்சியை ஆய்ந்தறிதல் (Exploring the water cycle of the 'Blue Planet') http://www.esa.int/esapub/bulletin/bulletin137/bul137b_drinkwater.pdf என குறிப்பிடப்பட்டுள்ளது. எனவும் குறிப்பிடுகின்றனர்.

மாந்தர்கள் உட்பட பல்லாயிரக்கணக்கான உயிரினங்கள்  வாழும் இடமான இந்தப் புவி, அண்டத்தில் உயிர்கள் இருப்பதாக அறியப்படும் ஒரே இடமாகக் கருதப்படுகின்றது. இந்தக் கோள் சுமார் 4.54 பில்லியன் ஆண்டுகளுக்கு முன்னர் உருவானது, மேலும் ஒரு பில்லியன் ஆண்டுகளுக்குள் அதன் மேற்பரப்பில் உயிரினங்கள் தோன்றின. அதுமுதல் புவியின் உயிர்க்கோளம் குறிப்பிடும் வகையில் அதன் வளிமண்டலம் மற்றும் உயிரற்ற காரணிகளை மாற்றியுள்ளது. அதனால் பல வளி சார்ந்த உயிரினங்கள் பெருகின. ஓசோன் மண்டலம் உருவாகி புவியின் காந்த மண்டலத்தோடு அகிலத்திலிருந்து வரும் தீங்கு விளைவிக்கும் கதிர்களைத் தடுத்து உலகில் உயிர்கள் தழைப்பதற்கு வழி ஏற்பட்டது. இக்காலகட்டங்களில் புவியின் பௌதிகத் தன்மையினாலும் புவி சூரியனைச் சுற்றி வந்தமையினாலும் உலகில் உயிர்கள் நிலைபெற்றன. உயிர்களுக்கு ஏதுவான தற்போதுள்ள சூழல் மேலும் 1.5 பில்லியன் ஆண்டுகளுக்கு நிலவும் எனவும், பிறகு வளரும் சூரியனின் வெப்ப ஒளிர்வுத் தன்மைகளால் புவியின் உயிர்க்கோளம் அழிக்கப்படும் எனவும் எதிர்பார்க்கப்படுகிறது.

புவியின் மேற்பரப்பு பல இறுக்கமான பிரிவுகளாக, அல்லது டெக்டோனிக் பலகைகளாக அமைந்துள்ளது. அவை புவியின் மேற்பரப்பில் சிறிது சிறிதாக பல மில்லியன் வருடங்களாக நகர்ந்து வருகிறது. புவியின் சுமார் 71% மேற்பரப்பு உப்பு நீருள்ள பெருங்கடல்களாலும் மற்ற பகுதிகள் கண்டங்கள், தீபகற்பங்கள் மற்றும் எல்லா உயிர்களுக்கும் அதிமுக்கியமான திரவ நீராலும் நிரப்பப்பட்டுள்ளது. சூரிய மண்டலத்தில் உள்ள மற்ற கிரகங்கள் அதிக வெப்பமாகவோ அல்லது குளிர்ந்தோ காணப்படுவதால் இந்த கிரகங்களில் திரவ நீர் காணப்படவில்லை. எனினும் செவ்வாய்க் கிரகத்தின் மேற்பரப்பில் மட்டும் திரவ நீர் இருப்பதாக உறுதியாக அறியப்படுகின்றது. மேலும் இன்று கூட அங்கு நீர் காணப்படுவதற்கான சாத்தியக் கூறுகள் அதிகம் எனலாம்.
 அடர்ந்த திட மூடகம் (Mantle) அடுக்கு, காந்த மண்டலத்தை உருவாக்கும் திரவ வெளி மையம் மற்றும் திட உள் மையம் ஆகியவற்றால் புவியின் உட்பகுதி மிகுந்த ஆற்றலுடன் இயங்குகிறது.

புவி, ஞாயிறு மற்றும் நிலா உட்பட பரவெளியில், உள்ள மற்ற பொருட்களுடன் ஊடாடுகிறது. தற்போது புவி தனது அச்சில் சுழல்வதோடு தோராயமாக 366.26 முறை கதிரவனையும் சுற்றி வருகின்றது. இதற்கான மொத்த கால அளவு ஒரு விண்மீன் ஆண்டு (sidereal year), இது 365.26 சூரிய நாட்களுக்குச் (solar day) சமம்.சூரிய நாட்களின் எண்ணிக்கை, விண்மீன் நாட்களை விட ஒன்று குறைவாகும், ஏனெனில் புவி சூரியனை சுற்றும் போது தனது அச்சில் ஒன்று கூடுதலாக சுழலுகிறது. புவியின் அச்சு சுழற்சி அதன் கோளப் பாதையிலிருந்து,யோடர், சார்லஸ் எப். (1995:8). 23.4° செங்குத்தாக விலகி சாய்ந்து இருப்பதால், கோளின் மேற்பரப்பில் கால மாறுபாடுகளை ஒரு வெப்ப ஆண்டுக்குத் (tropical year) தோற்றுவிக்கிறது (365.24 சூரிய நாட்கள்). புவியின் நாமறிந்த ஒரே இயற்கையான செயற்கைக்கோள் நிலா, 4.53 பில்லியன் ஆண்டுகளுக்கு முன்பிருந்து அதனைச் சுற்ற ஆரம்பித்தது, இது கடலில் அலைகளை உருவாக்குவதோடு, புவியின் அச்சு சாய்வை நிலைப்படுத்தி, அதன் சுழற்சியையும் சிறிது சிறிதாகக் குறைக்கிறது. தோராயமாக 4.1 மற்றும் 3.8 பில்லியன் ஆண்டுகளுக்கும் இடையே காலம் தாழ்ந்த பலத்த தாக்குதல் (Late Heavy Bombardment) நடந்த வேளையில் பெரு விண்கற்களின் (asteroid) தாக்கம் புவியின் சுற்றுச் சூழலில் குறிப்பிடத்தக்க மாறுதலை ஏற்படுத்தியது.

புவியின் கனிம வளங்கள் மற்றும் உயிர்க் கோளத்தில் உருவான பொருட்கள் இரண்டுமாக உலக மக்கள்தொகை பெருக்கத்திற்கு துணை புரியும் வகையில் வளங்களை அளித்தது. அங்கு வாழ்பவர்கள் 200 தனித்த ஏகாதிபத்திய நாடுகளாக குழுவாக்கப்பட்டு, அரசியல், பயணம், வணிகம் மற்றும் இராணுவ செயல்பாடுகள் மூலமாக தொடர்பு கொண்டனர். தெய்வ வழிபாடு உட்பட, தட்டையான புவி அல்லது அண்டத்தின் மையத்தில் புவி உள்ளது போன்ற நம்பிக்கைகள், நவீன உலகப்பார்வையில் ஒருமைப்பாட்டுடன் ஒருவருக்கொருவர் உதவி புரிந்து வாழும் இடம் என மக்கள் கலாச்சாரம் இக்கோளை பற்றி பல்வேறு விதமான தோற்றத்தை ஏற்படுத்தியுள்ளது.

 காலவரிசை

அறிவியல் அறிஞர்கள் புவியின் கடந்த கால வரலாற்றை பற்றி விரிவாக வரையறுத்துள்ளனர். சூரிய மண்டலத்தில் காணப்படும் மிகப் பழமையான பொருள் 4.5672 ± 0.0006 பில்லியன் வருடங்களுக்கு முந்தியது. கடந்த 4.54 பில்லியன் வருடங்களுக்குள் (1% ஐயப்பாட்டுடன்) பரிதி உருவாகி, எஞ்சிய வாயு மற்றும் தூசுப்பொருட்களால் ஆகிய தட்டு வடிவத்தில் இருந்த சூரிய நெபுலாவிலிருந்து புவி மற்றும் மற்ற கோள்கள் தோன்றின. இவ்வாறு இயற்கையான சேர்மானத்தால் 10–20 மில்லியன் வருடங்களுக்குள் புவியின் பெரும்பான்மையான பகுதி உருவாகியது. வளிமண்டலத்தில் நீர் சேர ஆரம்பித்தவுடன் முதலில் உருகிய நிலையில் இருந்த புவியின் மேற்பரப்பு குளிர்ந்து இறுகத் தொடங்கியது. இதற்குப்பின் புவியின் இயற்கை துணைக்கோள் நிலா உருவானது. நிலா, செவ்வாய் கிரகத்தின் பரப்பை ஒத்த ஒரு விண் வெளி பொருள் (தீயா என்று சில சமயம் அழைக்கப்படும்), புவியின் பத்தின் ஒரு பங்கு திண்மத்தை  கொண்டதுமாகிய அப்பொருள் புவியின் மீது கொண்ட தாக்கத்தால் உருவாகியிருக்கலாம் என நம்பப்படுகிறது. இவ்வேற்றுலக பொருளின் ஒரு பகுதி புவியுடன் கலந்திருக்கலாம் எனவும் மற்ற பகுதிகள் விண் வெளியில் சிதறியும், புவியின் காந்த விசையால் புவியை சுற்றும் பாதையை அடைந்து சந்திரனாகவும் மாறியிருக்கலாம் எனவும் எண்ணப்படுகிறது.

எரிமலை சீற்றம் மற்றும் வாயுக்களின் வெளிக்கொணர்வு ஆகியன ஆதிகால புவியின் வளிமண்டலத்தை உருவாக்கின. விண் பெருகற்கள், வால் நட்சத்திரம், பெரிய முன்கிரகங்கள் மற்றும் நெப்ட்டியூனைத் தாண்டி உள்ள சூரிய மண்டலத்திலுள்ள விண் வெளிப் பொருட்களிலிருந்து பெறப்பட்ட பனிக்கட்டி, நீர் ஆகியனவும் வளிமண்டலத்திலிருந்து சுருங்கும் நீராவியினாலும், சமுத்திரங்கள் உருவாகின.

கண்டங்களின் படிப்படியான வளர்ச்சியை விவரிக்க இரு மாதிரிகள் விவரிக்கப்பட்டுள்ளன: இன்றுவரை நிலையான மாற்றத்தினால் அவை உண்டானது என்பதும் மற்றொன்று புவியின் ஆரம்பகாலத்திலேயே துரித மாற்றத்தினால் அவை ஏற்பட்டன என்பதுவாகும்.
தற்போதைய ஆய்வின்படி இரண்டாவது கூற்றே, அதாவது புவியின் ஆரம்பத்திலேயே துரித வளர்ச்சியுடன் கண்டங்களின் ஓடு உருவாகிவிட்டதென்றும், பிறகு அவை நிரந்தர கண்ட பரப்பாக உருவாகியதே ஏற்கக்கூடியதாக உள்ளது. பல நூறு மில்லியன் வருட கால அளவில் நோக்கும் போது, புவியின் மேற்பரப்பு கண்டங்கள் தொடர்ச்சியாக உருவாவதாலும் அழிவதாலும் மாறிக்கொண்டு வந்துள்ளது. இதனால் கண்டங்கள் புவியின் மேற்பரப்பில் நகர்ந்து எப்போதாவது ஒன்றோடு ஒன்று இணைந்து மகா கண்டங்கள் உருவாகின. தோராயமாக 750 மில்லியன் வருடங்களுக்கு முன் (மிமு), அப்போதறிந்த மகாகண்டம் ரோடினியா (Rodinia), உடைய ஆரம்பித்தது. அது பின்னர் இணைந்து பென்னோஷயா (Pannotia) என்ற கண்டமாக உருமாறி பின், 600–540 மிமுவின், பின் இறுதியில் பாஜ்சியா (Pangaea) என்ற கண்டமாக உருவடைந்து, பின் 180 மிமுவில் மீண்டும் உடைந்து பிரிந்தது.

 உயிர்களின் பரிணாம வளர்ச்சி
இன்றைய நிலையில், புவியில் மட்டுமே உயிர்களின் பரிணாம வளர்ச்சி ஏற்பட ஏதுவான சூழல் உள்ளது. நான்கு பில்லியன் ஆண்டுகளுக்கு முன் ஆற்றல் மிகு வேதியியல் வினைகளால் சுயமாக உருவாகும் மூலக்கூறுகள் ஏற்பட்டன, பிறகு அரை பில்லியன் வருடங்களுக்குள் எல்லா உயிரினங்களின் பொது மூதாதையரான உயிரினம் உருவாகியது. தாவர உயிரினங்களின் ஒளிச்சேர்க்கைத் தன்மையினால் சூரிய ஆற்றலை உபயோகப்படுத்தின; இந்த வேதி வினையினால் ஏற்பட்ட பிராணவாயு (ஆக்சிஜன்) வளிமண்டலத்தை நிரப்பியது. மேலும் ஓசோன் (ஆக்சிசன் மூலக்கூறின் ஒருவடிவம் [O3]) படலம் மேல் வளி மண்டலத்தில் உருவாக உதவியது. பல சிறு செல்கள் பெரிய செல்களுடன் சேர்ந்ததினால் நுணுக்கமான செல்கள் யூகேர்யோட்டுகள் (eukaryotes) உருவாகின. இப்படிப்பட்ட காலனிகளில் அடங்கிய செல்கள் தனித்தன்மையுடன் செயல்படத் தொடங்கியபோது உண்மையான பல செல் படைத்த உயிரினங்கள் உருவாகின. மேலும் வளி மண்டலத்தின் மேற்பரப்பில் அமைந்த ஓசோன் மண்டலம் வெளியிலிருந்து புவிக்கு வரும், கேடு விளைவிக்கும் புற ஊதாக் கதிர்களை உறிஞ்சியதால் பூவுலகில் உயிர்கள் தழைத்தன.

1960 ஆம் ஆண்டு முதல் ஆய்வாளர்கள், நியோபுரோட்டிசோயிக் காலத்தில் அதாவது 750 மற்றும் 580 மிமுவில் புவியின் பெரும்பகுதி பனியால் மூடியிருந்ததென்றும் மற்றும் மிகப்பல பனிக்கட்டியாறுகள் ஓடியதென்றும் அறிவிக்கின்றனர். அந்தக் காலத்திய புவியை "பனிப்பந்து புவி" என அழைக்கின்றனர். அந்த காலகட்டம் மிகவும் இன்றியமையாததாக கருதப்படுகிறது ஏனெனில் இது பல செல் உயிரினங்கள் தோன்றி பரவிய கேம்ப்ரியன் விரிவாக்க காலத்திற்கு முன்னால் வந்தது.

கேம்ப்ரியன் காலத்து விரிவாக்கத்தைத் தொடர்ந்து, 535 மில்லியன் வருடங்களில் புவியில் ஐந்து பேரழிவுகள் ஏற்பட்டுள்ளன. கடைசியாக ஏற்பட்ட பேரழிவு 65 மில்லியன் வருடங்களுக்கு முன் ஒரு பெரிய விண்கல் புவியில் வந்து விழுந்ததால் ஏற்பட்டிருக்கக் கூடும் என நம்பப்படுகிறது. இந்த தாக்கத்தினால் டைனோசர் உட்பட பல ராட்சத பல்லிகள் மற்றும் பறவையினங்களைத் தவிர்த்து மற்ற எல்லாமுமே கூண்டோடு அழிந்து போனது. இதில் தப்பியது எலியைப் போன்ற ஷ்ரூ என்றழைக்கப்படும் பாலுண்ணிகளே. கடந்த 65 மில்லியன் வருடங்களில் பாலுண்ணிகள் பல்வேறு பரிணாமங்களை அடைந்துள்ளன, சில மில்லியன் வருடங்களுக்கு முன், ஆப்பிரிக்கா கண்டத்தில் மனிதக்குரங்கைப் போன்ற ஓர் மிருகம் நிமிர்ந்து நிற்க ஆரம்பித்தது. அவ்வாறு நின்றதால் கருவிகளை உபயோகிக்கவும் தகவல் பரிமாறவும் முடிந்தது, இதுவே மூளையின் வளர்ச்சிக்கு வித்திட்டது. இவ்வாறு அதிவிரைவாக வளர்ந்த மனிதனே முதலில் புவியில் விவசாயம் மற்றும் நாகரீகத்தையும் அறிமுகப்படுத்தினான். இதனால் ஏற்பட்ட தாக்கம் மற்ற புவி வாழ் உயிரினங்களின் வாழ்க்கை மற்றும் போக்கு இவற்றை மாற்றியமைத்தது.

இப்போதுள்ள பனிக்கால சுழற்சி 40 மில்லியன் வருடங்களுக்கு முன் ஏற்பட்டதென்றும் மூன்று மில்லியன் வருடங்களுக்கு முன் பிளாய்டோசீன் காலத்தில் தீவிரமடைந்தது என்றும் கூறப்படுகிறது. அது முதல் துருவப் பகுதிகளில் உள்ள பனி 40–100,000 ஆண்டுகளுக்கொரு முறை உருகியும், உறைந்தும் ஏற்படுகின்றது. கடைசி பனிக்காலம் 10,000 வருடங்களுக்கு முந்தி முடிவடைந்தது.

 எதிர்காலம்
பரிதியின் வாழ்க்கைச் சுழற்சி
புவியின் எதிர்காலம் சூரியனைச் சார்ந்துள்ளது. சூரியனின் உட்கருவில் சேர்ந்து வரும் ஹீலியம் வாயுவினால், அதன் மொத்த ஒளிர்வுத்தன்மை மெல்ல வளரும். சூரியனின் இந்த ஒளிர்திறன் அடுத்த 1.1 கிகா ஆண்டுகளில் (1.1 நூறு கோடி வருடங்கள்) 10 சதவிகிதமும் அடுத்த 3.5 கிகா  ஆண்டுகளில் 40 சதவிகிதமும் அதிகரிக்கும். காலநிலை கணிப்பின்படி புவியை வந்தடையும் அதிக கதிர்வீச்சு, கடல் இழப்பு போன்ற மோசமான விளைவுகளை ஏற்படுத்தும்.

புவியின் மேற்பரப்பு வெப்பம் அதிகரிப்பதால் அசேதன CO2 சுழற்சியை துரிதப்படுத்தி, அடுத்த 900 மில்லியன் வருடங்களில் தாவரங்களுக்கு அத்தியாவசியமான கரியமலவாயு (C4 ஒளிச்சேர்க்கைக்குத் 10 பிபிஎம்) வளிமண்டலத்தில் குறையும். தாவரங்கள் அழிவதால் அது வெளியிடும் ஆக்சிஜன் தடைப்படும், அதனால் மற்ற உயிரினங்கள் சில மில்லியன் ஆண்டுகளிலேயே முழுவதுமாக அழிந்து விடும்.வார்ட் மற்றும் பிரவுன்லே (2002) சூரியன் அழிவில்லாத மற்றும் நிலையான ஒன்றாக இருந்தாலும், குறைந்த எரிமலையாக்கத்தின் காரணமாக புவியின் உட்புற குளிர்ச்சி பெரும்பான்மையான வளி மண்டலத்தையும் கடற் பரப்பையும் குறைத்திருக்ககூடும். அடுத்த நூறு கோடி வருடங்களில் புவியின் மேற்பரப்பில் உள்ள தண்ணீர் அனைத்தும் மறைந்திருக்கும். மேலும் புவியின் சராசரி வெப்பநிலை 70 °C யை வந்தடையும். அந்தக் கால கட்டத்திலிருந்து அடுத்த 500 மில்லியன் வருடங்களுக்கு புவி வாழ்வதற்கு ஏற்றதாக இருக்கும் என எதிர்பார்க்கப்படுகிறது. இருந்தபோதிலும் வளிமண்டலத்தில் உள்ள நைட்ரோஜன் நீக்கப்படுமானால் இது மேலும் 2.3 பில்லியன் ஆண்டுகளுக்கு நீட்டிக்கப்படலாம்.

சூரியன் அதன் பரிணாம வளர்ச்சியில் மற்றும் 5 பில்லியன் வருடங்களில் ஒரு மாபெரும் சிகப்பு நட்சத்திரமாக மாறும். சூரியன் தற்போதைய அரைவிட்டத்தை போல தோராயமாக 250 மடங்கு விரிவடையும் என்று உருமாதிரிகள் கணிக்கின்றன. இதனையும் பார்க்கவும் புவியின் தலைவிதி தெளிவாகத் தெரியவில்லை. மாபெரும் சிகப்பு நட்சத்திரமாகிய சூரியன், தன்னுடைய அதிகபட்ச ஆரத்தை எட்டும் போது, சூரியன் தன் எடையில் 30% த்தை இழக்கும் அப்போது அலைகளினால் ஏற்படும் தாக்கம் இன்றியே, புவி சூரியனிலிருந்து  அளவு கொண்ட சுற்றுப்பாதைக்குத் தள்ளப்படலாம். அவ்வாறு தள்ளிப்போவதால், சூரியனின் வெளி மண்டலத்தின் தாக்கத்திலிருந்து புவி தன்னைக் காத்துக் கொள்ளும், ஆனால் சூரியனின் அதிகமாகும் ஒளிர்வுக் கதிர்களால், எல்லா உயிரினங்களும் அழிந்து போகும். எனினும், சமீபத்திய ஆராய்ச்சியின்படி அலைகளால் ஏற்படும் தாக்கத்தால், புவி அதன் சுற்றுப்பாதையிலிருந்து விலகி, மாபெரும் சிகப்பு நட்சத்திரமான சூரியனின் வளிமண்டலத்தில் நுழைந்த முழுவதுமாக கரைந்து போகலாம்.

 புவியின் சேர்மானமும் கட்டமைப்பும்
புவி ஒரு திடமான கிரகம், அதாவது முழுவதும் காற்றாலே ஆன மாபெரும் வாயுக்கிரகமான வியாழன் போலல்லாது கடினமான உடலால் ஆனது. இது சூரியக் குடும்பத்திலுள்ள நான்கு திட கிரகங்களுள் உருவத்திலும் திண்மத்திலும் மிகப் பெரியது. இந்த நான்கு கிரகங்களில், புவி அதிக அடர்த்தியானதும், மிகுந்த மேற்பரப்பு புவியீர்ப்பு விசையைக் கொண்டதும், வலிமையான காந்தப் புலனைக் கொண்டதும் மற்றும் வேகமான சுழற்சியைக் கொண்டதுமாகும். திடக் கிரகங்களிலேயே புவியில் மட்டுமே டெக்டோனிக் தட்டுகளின் நகர்தல் காணப்படுகிறது.

 வடிவம்
thumbnail|right|300px|உட்கிரகங்களின் அளவு ஒப்பீடு (இடமிருந்து வலமாக): புதன், வெள்ளி, புவி மற்றும் செவ்வாய்
புவியின் உருவம் துருவங்களில் தட்டையாகவும் நிலநடுக் கோட்டிற்கு அருகில் விரிவடைந்தும் உள்ள நீள்வட்ட கோளத்தைப் போல் காணப்படுகின்றது.
புவியின் சுழற்சியால் இந்த இடை விரிவாக்கம் ஏற்பட்டுள்ளது, மேலும் விட்டங்களை ஒப்பிடுகையில் நிலநடுக்கோடு துருவங்களை விட 43 கிமீ அதிகமாயுள்ளது. இக் கோளத்தின் சராசரி விட்டம் 12,742 கிமீ (7,918 மைல்) அதாவது 40,000 கிமீ/π, ஏனென்றால் மீட்டரை முதலில் வரையறுக்கும் போது அது பூமத்திய ரேகையிலிருந்து வட துருவத்திற்கு பிரான்ஸில் உள்ள பாரிஸ் நகர வழியாக கணக்கிடும் தூரத்தில் 1/10,000,000 ஈடாக கொள்ளப்பட்டது.

புவி அதன் இடவமைப்பான (topography) சிறு மேடு பள்ளங்களை வைத்து காணும் போது கோள வடிவிலிருந்து புவி மாறுபடும் ஆனால் மொத்தத்தில் இந்த வேறுபாடு மிகவும் சிறியது: உண்மையான கோளத்தோடு ஒப்பிடுகையில் புவி 584 அல்லது 0.17% விலகியுள்ளது, இது பில்லியர்ட்ஸ் விளையாட்டில் பயன்படுத்தப்படும் பில்லியர்ட் பந்திற்கு ஏற்றுக் கொள்ளக்கூடிய 0.22% மாற்றத்தை விட சிறியதே. புவியின் மேற்பரப்பில் மிக அதிகமாக கோள வடிவிலிருந்து விலகியுள்ள இரு இடங்கள் எவரஸ்ட் சிகரம் (கடல் மட்டத்திலிருந்து 8,848 உயரம்) மற்றும் மரியானா ட்ரென்ச் (கடல் மட்டத்திலிருந்து 10,911 மீ கீழுள்ளது). புவி, நிலநடுக்கோட்டருகே விரிந்திருப்பதால் பூமியின் நடுவிலிருந்து மிகவும் தள்ளி உள்ள இடம் நில நடுக்கோட்டருகே உள்ள ஈக்வெடார் நாட்டின் (Ecuador) சிம்போராசோ சிகரமாகும்.

+எப்.டபிள்யூ. கிளார்க்கின் ஆக்சைடு அட்டவணைசேர்மம்சூத்திரம்சேர்மானம் சிலிக்காSiO259.71% அலுமினாAl2O315.41% சுண்ணாம்புCaO4.90% மெக்னீஷியாMgO4.36% சோடியம் ஆக்சைடுNa2O3.55% இரும்பு (II) ஆக்சைடுFeO3.52% பொட்டாஷியம் ஆக்சைடுK2O2.80% இரும்பு(III) ஆக்சைடுFe2O32.63% நீர்H2O1.52% டைட்டானியம் டை ஆக்சைடுTiO20.60% பாஸ்பரஸ் பென்டாக்சைடு P2O50.22%மொத்தம்99.22%

 புவியின் இரசாயன சேர்மானம்
பூமியின் நிறை ஏறக்குறைய 5.98 கி.கி. ஆகும். பூமி, இரும்பு (32.1%), ஆக்சிஜன் (30.1%), சிலிக்கன் (15.1%), மெக்னீஷியம் (13.9%), சல்பர் (2.9%), நிக்கல் (1.8%), கால்சியம் (1.5%), மற்றும் அலுமினியம் (1.4%); மீதமுள்ள 1.2% மிகவும் குறைந்த அளவிலுள்ள தனிமங்களால் ஆனது. நிறை பிரிவினால் புவியின் உட்கரு பிரதானமாக இரும்பினாலும் (88.8%) சிறிதளவு நிக்கல் (5.8%) மற்றும் சல்பர் (4.5%) ஆகியவற்றாலும், மேலும் ஒரு விழுக்காடு அரிதான தனிமங்களாலும் ஆகியுள்ளது.

புவியியலாளர் எப். டபிள்யூ. கிளார்க் 47 விழுக்காட்டுக்கு சிறிது கூடதலான பிராணவாயு இருப்பதாக கணக்கிட்டுள்ளார். பூமியின் மேற்பரப்பில் பரவியிருக்கும் கற்கள் பெரும்பாலும் ஆக்சைடுகளாலேயே ஆனது. மற்ற குளோரின், சல்பர், ப்ளூரின் இவை 1% க்குள் அடங்கும். இவற்றில் முதன்மையான ஆக்சைடுகள் சிலிக்கா, அலுமினா, இரும்பு ஆக்சைடு, சுண்ணாம்பு, மெக்னீசியா, பொட்டாஷ் மற்றும் சோடா ஆகும். சிலிகா அமிலத்தைப் போல் செயல்பட்டு சிலிக்கேட்டுகளை உருவாக்குகின்றது. பெரும்பாலும் தீப்பாறையில் காணப்படும் எல்லா கனிமங்களும் இதைப் போலவே செயல்படுகின்றன. ஏறத்தாழ 1,672 வகையான பாறைகளை ஆராய்ந்து பார்த்ததில் புவியியலாளர் கிளார்க் 11 வகையான ஆக்சைடுகள் (வலது பக்கம் உள்ள அட்டவணையைப் பார்க்க) 99.22% இருப்பதாக கண்டறிந்துள்ளார். இதர எல்லா தனிமங்களும் வெகு சிறிதளவே இவற்றில் அடங்கியுள்ளது.

 புவியின் உள்கட்டமைப்பு

புவியின் உட்பகுதி மற்ற திட கோள்களைப் போல் அதன் வேதியியல் அல்லது இயற்பியல் (பாய்வு) பண்புகளின் திடப்பொருட்களின் ஓட்டம் கொண்டு பல்வேறு பிரிவுகளாகப் பிரிக்கப்பட்டுள்ளது. புவியின் வெளி வடிவம் சிலிக்கேட்டால் ஆன திட மேல் ஓடு, இதனடியே பாகு நிலையிலுள்ள திட மூடகம் உள்ளது. புவியின் மேலோடு மூடகத்திலிருந்து மோஹோரோவிசிக் தொடர்பின்மையினால் பிரிக்கப்பட்டுள்ளது, மேலும் மேலோட்டின் தடிமன் சமச்சீராக இல்லை: கடல்களுக்கு அடியில் சராசரியாக 6 கி.மீட்டரும் நிலப்பரப்பில் 30–50 கி.மீ. வரையிலும் உள்ளது. புவியின் மேலோடு மற்றும் குளிர்ந்த, கடினமான மேல் மூடகம் இணைந்தது லித்தோ அடுக்கு (lithosphere) ஆகும்; நிலவியல் பலகைகள் இந்த லித்தோ அடுக்கிலேயே அமைந்துள்ளது. லித்தோ அடுக்கிற்கு கீழே இருப்பது அஸ்த்னோ அடுக்கு (asthenosphere), ஒப்பிடுகையில் குறைந்த பாகு நிலையில் உள்ள இந்த படிவத்தின் மேலே லித்தோ அடுக்கு நகர்கின்றது. மூடகத்தினூடே முக்கியமான பளிங்கு கட்டமைப்பு மாறுதல்கள் 410 முதல் 660 கிமீ ஆழத்திலேயே உருவாகின்றது, இந்த மாறுதல் வளையம் மேல் மற்றும் அடி மூடக படிவங்களைப் பிரிக்கின்றது. மூடகத்தினூடே மிகவும் குறைந்த பாகுநிலையில் வெளிக்கருவும் அதனடியில் திடமான உட்கருவும் உள்ளது. உட்கருவானது மற்ற புவியின் பகுதிகளை விட அதிகமான கோண வேகத்தில் சுழல்கிறது, அதாவது ஒவ்வொரு வருடமும் 0.1–0.5° அதிகமாகிறது.

+புவியின் பல்வேறு அடுக்குகளின் தோற்றம்250px|centerஉட்கரு முதல் எக்சோ அடுக்கு வரையிலான புவியின் குறுக்கு வெட்டு தோற்றம்.ஆழம் கிமீபுவியின் பல்வேறு அடுக்குஅடர்த்திகி/செமீ30–60 லித்தோ அடுக்கு5 முதல் 200 கி.மீ. வரை மாறுபடும்.—0–35 ...மேல் ஓடு5 முதல் 70 கி.மீ. வரை மாறுபடும்.2.2–2.935–60மேல் மூடகம்3.4–4.4100–700 மூடகம்3.4–5.635–2890 அஸ்த்னோ அடுக்கு—2890–5100 வெளிக்கருவம்9.9–12.25100–6378 உட்கருவம்12.8–13.1

 பூமியின் வெப்பம்
பூமியின் உட்புற வெப்பம் கிரகச் சேர்க்கையினால் உண்டாகும் மீத வெப்பத்தாலும் (சுமார் 20%) மற்றும் அணுச் சிதைவுகளாலும் (80%) உருவானது. பூமியில் அதிகமான வெப்பத்தை உருவாக்கும் ஐசோடோப்புகள் பொட்டாசியம்-40, யுரேனியம்-238, யுரேனியம்-235 மற்றும் தோரியம்-232 ஆகும். பூமியின் மத்தியில் வெப்பம் 7,000 கெல்வினையும் மற்றும் அழுத்தம் 360 கிகாபா (GPa)-வையும் அடையலாம். பூமியின் வெப்பம் பெரும்பாலும் அணுச்சிதைவிலிருந்து உருவாவதால், அறிவியலாளர்கள் பூமியின் ஆரம்பகால கட்டத்தில், குறைந்த அரை வாழ்வு கொண்ட ஐசோடோப்புகள் மறையுமுன், புவியின் வெப்பம் அதிகமாயிருந்திருக்கும் என்றும் மூன்று பில்லியன் வருடங்களுக்கு முன்  தற்போதைய வெப்பத்தை விட இருமடங்கு வெப்பம் உற்பத்தி ஆகிய போது, பூமியின் வெப்பம்சார் தன்மைகள் மாறியிருக்கும், அதிகமான மூடக பரப்பலும், டெக்டோனிக் பலகை நகர்தலும், மேலும் கோமடைட்ஸ் (komatiites) என்ற தீப்பாறைகள் உருவானதும் (இவை இன்று உருவாவதில்லை) ஏற்பட்டிருக்கும் என்று நம்புகின்றனர்.

+தற்போது அதிக வெப்பத்தை உருவாக்கும் ஐசோடோப்புகள்ஐசோடோப்வெளியிடும் வெப்பம் [வா/கிகி ஐசோடோப்]அரை வாழ்வு [ஆண்டு]சராசரி மூடக அடர்த்தி [கிகி ஐசோடோப்/கிகி மூடகம்]வெளியிடும் வெப்பம் [வா/கிகி மூடகம்] 238U         235U         232Th         40K

பூமியிலிருந்து ஏற்படும் மொத்த வெப்ப இழப்பு 163  உட்கருவின் வெப்ப ஆற்றலில் ஒரு பகுதி மூடக ஆழ் கிணறுகளின் (mantle plumes) மூலமாக மூடகத்திற்கு கடத்தப்படுகிறது; இது ஒருவகை அதி வெப்பப் பாறை எனலாம். இந்த வெப்ப ஆழ் கிணறுகள் வெப்ப மையங்களையும் வெப்ப பாறை வெள்ளத்தையும் ஏற்படுத்தவல்லது.

பூமியின் மிகையான வெப்ப இழப்பு டெக்டோனிக் பலகை நகர்வதாலும் நடுக்கடல் மேடுகளுடன் சேர்ந்து மூடகங்கள் மேல்நோக்கி நகர்வதாலும் ஏற்படுகின்றது. இறுதியாக மிக அதிக வெப்ப இழப்பு, லித்தோ அடுக்கின் வெப்ப கடத்தலால் ஏற்படும், அதாவது பெரும்பாலும் அவை கடல் வழியே ஏற்படும் ஏனெனில் தரையை விட கடலினடியில் உள்ள லித்தோ அடுக்கின் பருமன் குறைவு.

 நிலப்பலகைத் தட்டு

+ புவியின் முக்கிய தட்டுகள் 250pxதட்டின் பெயர்பரப்பளவு106கி.மீ.² ஆப்பிரிக்க தட்டுசோமாலியத் தட்டு உட்பட, இது தற்போது ஆப்பிரிக்க தட்டிலிருந்து தோன்றும் செயலில் உள்ளது. பார்க்க:78.0 அண்டார்க்டிக் தட்டு60.9 ஆத்திரேலியத் தட்டு47.2 யுரேசியத் தட்டு67.8 வட அமெரிக்கத் தட்டுத் தட்டு75.9 தென் அமெரிக்கத் தட்டு43.6 பசுபிக் தட்டு103.3

மிகவும் இறுக்கமான புவியின் மேல் பரப்பு, லித்தோ அடுக்கு எனப்படும் இது, நிலப்பலகைத் தட்டுகளாக உடைந்து பிரிந்திருக்கின்றது. இந்தத் தட்டுகள் இறுக்கமான அமைப்புகளைக் கொண்டது மேலும் அவை ஒன்றோடொன்று நகர்ந்து மூன்று வகைத் தட்டுளாக எல்லைகளை உருவாக்குகின்றன: அவை முறையே குறுகும் எல்லைகள், இரண்டு தட்டுகள் ஒன்றை நோக்கி மற்றொன்று நகர்தல், விலகும் எல்லைகள், பலகைகள் ஒன்றைவிட்டு மற்றொன்று விலகுதல் மற்றும் உருமாறும் எல்லைகள், இரண்டு தட்டுகள் ஒன்றோடு ஒன்று பக்கவாட்டில் உரசிச் செல்வது என்பனவாம். இந்த செயல்களால் தட்டுகளின் எல்லைகளில் பூகம்பம், எரிமலைகள், மலைகள் உருவாக்கம் மற்றும் ஆழ் கடலடிப் படுபள்ளங்கள் உருவாகுகின்றன.
நிலப்பலகைத் தட்டுகள் அசுதனோ அடுக்கின் மேல் நகர்ந்துச் செல்கின்றது, அதாவது இவ்வடுக்கின் பாகு நிலையிலுள்ள ஆனால் திடமான மேல் மூடகத்தின் பகுதிகள் நிலப்பலகைத் தட்டுகளுடன் நகரக்கூடிய தன்மையைக் கொண்டதாய் உள்ளது,
மேலும் இவற்றின் இயக்கம் புவியின் மூடகத்தின் உள்ளே ஏற்படும் இயக்க மாதிரிகளை சார்ந்தே அமைகின்றது.

நிலப்பலகை தட்டுகள் கோளின் மேற்பரப்பில் நகர்வதால், குறுகும் எல்லைகளில் உள்ள பெருங்கடல் தரைகள் உள்ளிழுத்துக் கொள்ளப்படுகின்றது. அதே சமயம், தட்டுகளில் விலகு எல்லைகளால் மூடகப் பொருட்கள் வெளியேறி நடுப் பெருங்கடல் அகழிகள் உருவாகின்றன. இந்த இரு செயல்களாலும் பெருங்கடல் கீழ் புவியின் மேலோடு தொடர்ச்சியாக மூடகத்தோடு மீள் சுழற்சியில் ஈடுபடுகின்றது. இந்த மீள் சுழற்சியால், பெரும்பாலான பெருங்கடல் கீழ் புவியின் மேலோடு 100 மில்லியன் ஆண்டுகளுக்கு உட்பட்டவையே. உலகிலேயே பழமையான பெருங்கடல் கீழ் புவியின் மேலோடு சராசரியாக 200 மில்லியன் ஆண்டுடையது. இது மேற்கு பசிபிக் பெருங்கடலில் அமைந்துள்ளது. ஒப்பிட்டுப் பார்க்கையில் பழமையான கண்டங்களின் மேலோடு 4030 மில்லியன் வருடம் பழமையானது.

மற்ற முக்கிய தட்டுகள், இந்தியத் தட்டு, அரேபியத் தட்டு, கரீபியத் தட்டு, தென் அமெரிக்காவின் வடகரையில் இருக்கும் நாசுகாத் தட்டு மற்றும் தெற்கு அட்லாண்டிக் பெருங்கடலில் உள்ள சுகோசியத் தட்டு என்பனவாம். ஆஸ்திரேலியத் தட்டு இந்தியத் தட்டுடன் 50 முதல் 55 மில்லியன் ஆண்டுகளுக்கு முன் இணைந்தது. பெருங்கடல் தட்டுகளிளே மிகவும் வேகமாக நகர்ந்து கொண்டிருப்பவை, இதில் கோகோசுத் தட்டு வருடத்தில் 75 மீட்டரும் மற்றும் பசிபிக் பெருங்கடல் தட்டு ஆண்டிற்கு 52–69 மி.மீ. வரையிலும் நகர்கின்றன. மறுபுறத்தில் மிகவும் மெதுவாக நகரும் தட்டுகளில் யுரேசியன் தட்டு ஆகும், இது வருடத்திற்கு 21 மீட்டர் தூரம் நகர்கின்றது.

 மேற்பரப்பு
பூமியின் நிலம் இடத்திற்கு இடம் மிக வேறுபட்டுள்ளது. பூமியின் மேற்பகுதி 70.8% நீரினால் சூழப்பட்டுள்ளது மேலும் கண்டங்களின் அடுக்குப் பகுதிகள் கடலுக்கடியே உள்ளன. நீரால் மூழ்கப்பட்ட இடங்களில் மலை போன்ற அமைப்புகள், பூமி முழுவதும் பரவியுள்ள நடுப்பெருங்கடல் மலைத்தொடர், எரிமலைகள், பெருங்கடல் அகழிகள், ஆழ்கடல் படுபள்ளங்கள், பெருங்கடல் பீடபூமிகள் மற்றும் ஆழமான கணக்கிலடங்கா சமவெளிகள் இவையாவும் அடங்கும். இதைத் தவிர்த்து பூமியின் மீது தண்ணீருக்கு வெளியே உள்ள 29.2% இடத்தில் மலைகள், பாலைவனங்கள், சமவெளிகள், பீடபூமிகள் மற்றும் நிலப்பரிமாண அமைப்புகளும் அடங்கும்.

பூமியின் மேற்பரப்பு டெக்டோனிக் செயல்கள் மற்றும் அரித்தலால் காலப்போக்கில் உருமாறிக் கொண்டே இருக்கிறது மேற்பரப்பில் டெக்டோனிக் பலகை நகர்தலால் ஏற்படும் குவிந்த மற்றும் தகர்ந்த அமைப்புகள் மேலும் மழைகளால் (precipitation) சிதைவதும் வெப்ப சுழற்சி மற்றும் ரசாயனங்களாலும் தாக்கப்படுகின்றன. பனியாறு உருவாதல், கடற்கரை அரிப்பு, பவளப்பாறைகள் ஏற்படுதல் மற்றும் பெரும் விண்கற்களின் தாக்கம் ஆகியவற்றாலும் பூமியின் மேற்பரப்பு மாற்றியமைக்கப்படுகின்றது.
250px|left|thumbnail|பூமியின் தற்போதைய உயரம் மற்றும் ஆழம் தேசிய பௌதிக தகவல் மையத்தின் நிலம் சார்ந்த டிஜிட்டல் நில மாதிரி.

கண்டங்களின் மேலோடு குறைந்த திண்மத்தையுடைய தீப்பாறைகள், கிரானைட் மற்றும் அன்டிசைட்களால் (andesite) ஆனது. பசால்ட் எனப்படும் அதிக திண்மத்தைக் கொண்ட தீப்பாறைகள் அரிதாக காணப்படுகின்றன. மேலும் இவையே கடற்கரையில் காணப்படும் முக்கிய பாறைவகையாம். படிவுப்பாறைகள் வண்டல்கள் அழுத்தத்தினால் உருமாறி ஒன்று சேர்ந்து தோற்றுவிக்கப்படுகின்றன. படிவுப்பாறைகள் பூமியின் மேலோட்டில் 5% உள்ளது எனினும் அவை கண்டங்களின் மேற்பரப்பில் 75% மாக உள்ளது. பூமியின் மீது காணப்படும் மூன்றாவது வகைப் பாறைகள் உருமாறிப்பாறைகள், இவை மற்ற பாறைகள் அதிக அழுத்தம், அதிக வெப்பம் அல்லது இரண்டினாலும் உருப்பெயருவதால் ஏற்படுபவை. பூமியில் மிக அதிகமாகக் காணப்படும் சிலிக்கேட்டுகள் குவார்ட்ஸ், பெல்ட்ஸ்பார் (feldspar), ஆம்பிபோல் (amphibole), மைக்கா, பைராக்சீன் (pyroxene) மற்றும் ஒலிவைன் (olivine) ஆகும். பொதுவாக காணப்படும் கார்பனேட்டுகள் கால்சைட்டு (சுண்ணாம்பு கற்களில் காணப்படுவது), அராகோனைட்டு மற்றும் டோலோமைட்டு ஆகும்.

புவியில் எல்லாவாற்றிற்கும் மேலே உள்ள பரப்பு பீடோ அடுக்கு (pedosphere). இது மண்ணால் ஆனது மற்றும் இது மண் உருவாகும் செயலுக்கும் உட்பட்டது. இது லித்தோ அடுக்கு, வளிமண்டலம், நீர்க்கோளம் மற்றும் உயிர்க்கோளத்திற்கு இடையே உள்ளது. தற்போதைய நிலையில் பூமியின் மேற்பரப்பில் 13.31% மட்டுமே காற்றோட்டமான நிலமாகும் மற்றும் இதில் 4.71% இல் மட்டுமே நிரந்தர விவசாயம் செய்ய ஏற்றதாக இருக்கிறது. பூமியின் நிலப்பரப்பில் 40% இடம் விவசாயத்திற்கும், மேய்ச்சல் நிலத்திற்கும் பயன்படுகின்றது, அதாவது, தோராயமாக விவசாயத்திற்கு 1.3 கிமீ² நிலமும், மேய்ச்சலுக்கு 3.4 கிமீ² நிலமும் பயன்படுத்தப்படுகின்றது.

பூமியின் மேற்பரப்பிலிருந்து நிலத்தோற்றத்தைக் காணும் போது மிகவும் தாழ்வான இடம் −418 மீ ஆழத்தில் உள்ள சாக்கடல் (Dead Sea), மற்றும் 2005 ஆம் ஆண்டின் கணக்கெடுப்பின்படி மிகவும் உயரமான இடம் 8,848 மீட்டர் அளவு கொண்ட எவரெஸ்ட் சிகரம் ஆகும். நிலத்தின் சராசரி உயரம் கடல்மட்டத்திலிருந்து 840 மீட்டர் ஆகும்.

 நீர்க்கோளம்
thumbnail|300px|புவியின் மேற்பரப்பு பக்கத்தோற்ற வரைபடம். புவியின் மேற்பரப்பு தோராயமாக 71% நீரால் சூழப்பட்டுள்ளது.
பூமியின் மேற்பரப்பிலுள்ள நீர் அதன் தனித் தன்மையாகும் மற்றும் இதுவே நம் "நீலக்கிரகத்தை" சூரிய மண்டலத்திலுள்ள மற்ற கிரகங்களிலிருந்து வேறுபடுத்துகிறது. பூமியின் நீர்க்கோளம் முதன்மையாக பெருங்கடல்களால் ஆனது. ஆனால் முழுதாக கணக்கிலெடுத்தால் உள்நாட்டுக் கடல்கள், ஏரிகள், ஆறுகள் மற்றும் 2,000 மீட்டர் வரையுள்ள நிலத்தடி நீரும் இதிலடங்கும். அதிக ஆழமான நீருக்கடியில் இருக்கும் இடம் -10,911.4 மீட்டரில் பசிபிக் பெருங்கடலிலுள்ள மரியானா அகழியில் அமைந்திருக்கும் சாலஞ்சர் ஆழமாகும்.இந்த அளவீடு கைக்கோ (Kaikō) என்பதால் மார்ச் 1995 ஆம் ஆண்டில் எடுத்தது, இன்று வரை இதுவே மிகத்துல்லியமான அளவீடாக நம்பப்படுகிறது. மேலும் தகவலுக்கு சாலஞ்சர் ஆழம் என்ற கட்டுரையைப் பார்க்கவும். பெருங்கடல்களின் சராசரி ஆழம் 3,800 மீட்டர் ஆகும், இது கண்டங்களின் சராசரி உயரத்தைவிட நான்கு மடங்கு அதிகம்.

பெருங்கடல்களின் சராசரி நிறை 1.35 மெட்ரிக் டன்கள், அல்லது பூமியின் மொத்த நிறையில் 1/4400, மற்றும் 1.386கிமீ3 கனஅளவு இடத்தைப் பிடித்துள்ளது. பூமியின் நிலப்பரப்பு முழுவதும் சமமாக பரவியிருக்குமானால் நீரின் மட்டம் நிலத்தின் மீது 2.7 கி.மீ. உயர்ந்து இருக்கும்.புவியின் கடலின் மொத்த கொள்ளளவு 1.4கிமீ3. புவியின் மொத்த மேற்பரப்பு 5. 1கிமீ². எனவே, சராசரி ஆழம் இந்த இரண்டின் விகிதம் அல்லது 2.7 கி.மீ. மொத்த நீரில் 97.5% உப்பு நீராகும் மற்ற 2.5% தூய நீராகும். இதில் பெரும்பான்மையான தூயநீர், அதாவது 68.7% தற்போது பனிக்கட்டிகளாக உள்ளது.

பெருங்கடல்களின் மொத்த நிறையில் 3.5% உப்பாலானது. இந்த உப்பானது எரிமலை நிகழ்வுகளாலும் மற்றும் குளிர்ந்த தீப்பாறைகளிலிருந்தும் வெளிப்பட்டதாகும். வளிமண்டலத்திலுள்ள பல வாயுக்கள் பெருங்கடலில் கரைந்து அதில் வாழும் உயிரினங்களுக்கு ஆதாரமாய் உள்ளது. கடல் நீர் உலகின் பெரிய வெப்ப தேக்கமாக செயல்படுவதால் புவியின் வானிலையில் முக்கிய அங்கம் வகிக்கின்றது. பெருங்கடல்களில் வெப்பப் பங்கீட்டில் மாற்றம் நேரும் போது குறிப்பிடும் வகையில் வானிலை மாற்றங்கள் ஏற்படுவதால் எல் நினோ தெற்கு திசை ஊசலாட்டம் (ElNiño – Southern Oscillation) போன்றவை ஏற்படும்.

 வளிமண்டலம்
இந்த புவியின் மேற்பரப்பில் உள்ள வளி மண்டல அழுத்தம் சராசரியாக 8.5 கி.மீ. அளவு உயரம் வரை 101.325 கிலோபா (KPa) ஆக இருக்கிறது. இது 78% நைட்ரஜன், 21% ஆக்சிஜன் மற்றும் சிறிய அளவில் நீராவி, கரிமிலவாயு போன்ற மற்ற வாயு மூலக்கூறுகளையும் கொண்டுள்ளது. அடிவளிமண்டல (Troposphere) உயரமானது பூமியின் கிடைமட்ட பரப்பை பொறுத்து மாறும். தட்பவெப்ப மற்றும் காலநிலை மாறுபாட்டின் காரணமாக இது துருவங்களில் 8 கி.மீ. முதல் பூமத்தியரேகையில் 17 கி.மீ. வரை இருக்கும்.

புவியின் உயிர்கோளம் வளிமண்டலத்தில் குறிப்பிடத்தக்க மாற்றங்களை ஏற்படுத்தியுள்ளது.

2.7 பில்லியன் ஆண்டுகளுக்கு முன்னர் ஏற்பட்ட பிராணவாயு ஒளிச்சேர்க்கை முதன்முதலில் தற்போதுள்ள நைட்ரஜன் - ஆக்சிஜன் வளி மண்டலத்தை உருவாக்கியது. இந்த மாற்றமானது வளி சார்ந்த உயிரினங்கள் வளர்ச்சி மற்றும் ஓசோன் படலத்தையும் உருவாக்கியதோடு, புவியின் காந்தபுலம் புற ஊதாக் கதிர்கள் சூரியனின் கதிர்வீச்சு ஆகியவற்றை தடுத்து, புவியில் உயிரினங்கள் வாழ வழிசெய்கிறது. புவியில் உயிரினங்கள் வாழ்வதற்கு தேவையான நீராவி பரிமாற்றம், வாயுக்கள், சிறிய விண்கற்களை புவியை தாக்கும்முன் எரியசெய்தல் மற்றும் மிதமான வெப்பநிலை போன்றவற்றை அளிப்பதில் வளி மண்டலம் முக்கியப் பங்கு வகிக்கிறது. இறுதியாக குறிப்பிட்ட வளிமண்டல வெப்பநிலை மாற்றத்தை கிரீன் ஹவுஸ் மாற்றம் என குறிப்பிடுவர் (Greenhouse Effect): இது நிலத்தில் இருந்து வெளிவரும் வெப்ப ஆற்றலை வளிமண்டலத்தில் உள்ள சிறிதளவிலான மூலக்கூறுகள் சிறைப்படுத்தி அதன் மூலம் வளி மண்டலத்தின் சராசரி வெப்பத்தை உயர்த்துவதை குறிக்கும். கார்பன் டை ஆக்சைடு, நீராவி, மீத்தேன் மற்றும் ஓசோன் போன்றவை புவியின் வளி மண்டலத்தில் உள்ள பிரதான கிரீன் ஹவுஸ் வாயுக்கள் ஆகும். இந்த வெப்பம் தக்கவைத்தல் நடக்காவிடில் புவியின் மேற்புற வெப்பம் −18° செ ஆக இருந்திருக்கும் மற்றும் உயிரினங்கள் வாழ ஏதுவாய் இருந்திருக்காது.

 வானிலை மற்றும் பருவ நிலை
புவியின் வளிமண்டலத்திற்கு ஒரு குறிப்பிட்ட எல்லை கிடையாது, அது உயரே செல்ல செல்ல மெலிந்து அண்ட வெளியில் மறைந்து போகின்றது. வளி மண்டலத்தின் மொத்த நிறையில் மூன்றில் ஒரு பகுதி பூமியின் மேற் பரப்பிலிருந்து முதல் 11 கி.மீ.ரிலேயே அடங்கி விடுகின்றது. இந்த அடியில் உள்ள அடுக்கே அடிவளிமண்டலம் ஆகும். சூரியனிலிருந்து வரும் வெப்ப சக்தி இந்த அடுக்கை மற்றும் இதனடியில் உள்ள பூமியின் மேற்பரப்பையும் சூடு படுத்தி பிறகு இதனுடன் தொடர்புள்ள காற்றை விரிவாக்குகின்றது. இந்த குறைந்த அடர்த்தியுடைய காற்று மேலெழுகிறது, அவ்விடத்தை அதிக அடர்த்தியுள்ள குளிர்ந்த காற்று நிரப்புகின்றது. இவ்வாறு ஏற்படும் செயல் வளிமண்டலத்தில் சுழற்சியை ஏற்படுத்துகின்றது அதனால் வெப்ப சக்தி நகர்ந்து வானிலை மற்றும் பருவநிலை ஏற்பட காரணமாகின்றது.

முதன்மை வளிமண்டல சுழற்சியின் தடத்தில் நிலநடுக்கோட்டிலிருந்து 30° பாகைகள் உருவாகும் வியாபாரக் காற்றுகள் மற்றும் மேற்கத்திய காற்றுகள் இவை மத்திய-நில நேர்ககோட்டில்
30° மற்றும் 60° பாகைக்குள் உருவாகின்றன. பெருங்கடல்களின் ஓட்டமும் வானிலை மாற்றத்தில் பெரும் பங்கு வகிக்கின்றன, முக்கியமாக வெப்ப ஹேலைன் சுழற்சி பூமத்திய கடல்களில் இருந்து துருவக்கடல்களுக்கு வெப்ப ஆற்றலைப் பரப்புகிறது.

பூமியின் மேற்பரப்பில் ஏற்படும் நீராவி, சுழற்சியான முறையில் வளிமண்டலத்தை சென்றடைகிறது.

வளிமண்டலத்தின் நிலை அனுமதிக்கும் போது சூடான ஈரப்பதம் மிக்க காற்று மேலெழும்பி, பிறகு குளிர்ந்து, மழையாகி, பூமியை அடைகின்றது. இது பெரும்பாலும் ஆற்றின் மூலமாக பெருங்கடல் அல்லது ஏரிகளை சென்றடைகிறது இந்நீரின் சுழற்சி பூமியில் உயிரினங்கள் வாழ மிக முக்கியமானது மற்றும் வெகு காலமாக ஏற்பட்டுக்கொண்டிருக்கும் புவியின் மேற்புற அமைப்புகளின் அரிப்புகளுக்கும் காரணமாகின்றது. மழை பொழிவது இடத்திற்கு இடம் வெகுவாக வேறுபடுகின்றது, அது பல மீட்டரில் இருந்து சில மில்லி மீட்டர் வரை மாறுபடுகின்றது. ஒவ்வொரு இடத்திலும் காணப்படும் வளிமண்டல சுழற்சி, மேற்புற அமைப்பு மற்றும் வெப்ப மாற்றத்தை பொறுத்தே அவ்விடத்து மழை அமையும்.

பூமியின் பகுதிகளை அதன் நில நேர்க்கோட்டின் படி சராசரியான ஒரே தட்பவெப்ப நிலைகள் உள்ளவைகளாக பிரிக்கலாம். பூமத்திய ரேகையிலிருந்து துருவங்கள் வரையிலான தட்பவெப்பத்தை வெப்ப வளையம் (அல்லது ஈக்வடோரியல்), மிதவெப்ப வளையம், மிதமான வளையம் மற்றும் துருவ வளைய தட்பவெப்பம் என பிரிக்கலாம். தட்பவெப்பத்தை வெப்பம் மற்றும் பெய்யும் மழையைக்கொண்டும் வகைப்படுத்தலாம், அதாவது அவ்வவ்விடத்தின் சீரான காற்றின் அடர்த்தியைக் கொண்டும் பிரிக்கலாம். பொதுவாக உபயோகத்தில் உள்ள கோப்பெனின் தட்பவெப்ப முறையின் படி (விளாடிமிர் கோப்பெனின் மாணாக்கர் ருடால்ப் கைகர் மாற்றியமைத்தது) தட்பவெப்பங்களை ஐந்து பெரும் பிரிவுகளாக (ஈரப்பதம் மிக்க வெப்ப பகுதி, வறண்ட பகுதிகள், ஈரப்பதம் மிக்க மத்திய நில நேர்க்கோட்டு பகுதிகள், மிதமான குளிர் பகுதிகள் மற்றும் மிகக்குளிர் துருவ பகுதிகள்) பிரித்துள்ளார், மேலும் இவை குறிப்பிட்ட உட்பிரிவுகளாகவும் பிரிக்கப்பட்டுள்ளன.

 மேல் வளிமண்டலம்
thumbnail|right|300px|இந்த சுற்றுப் பாதையிலிருந்து பார்க்கும் போது, புவியின் வளிமண்டலம் முழுநிலவை பாதி மறைக்கிறது. நாசா படம்.
வளிமண்டலத்தில், அடி வளிமண்டலத்தின் மேற்பகுதி, வழக்கமாக ஸ்ட்ரடோ அடுக்கு (stratosphere), மீசோ அடுக்கு (mesosphere), வெப்பஅடுக்கு என பிரிக்கப்படுகிறது. ஒவ்வொரு அடுக்கும், அதன் உயரத்திற்கு ஏற்ப, தோன்றும் வெப்ப மாறுபாட்டிற்கு ஏற்றாற்போல் வெவ்வேறு இழப்பு விகிதத்தைக் கொண்டிருக்கும். இவற்றை தாண்டி, எக்சோ அடுக்கு எனப்படும் வெளி அடுக்கு மெலிந்து காந்த அடுக்கில் கலந்துவிடுகிறது. இந்த அடுக்கில்தான், பூமியின் காந்த புலம் சூரியக் கதிர் காற்றுடன் ஊடாடுகிறது. பூமியில் உயிர்கள் வாழ்வதற்கு தேவையான ஒரு பகுதி வளிமண்டலத்தில் உள்ள ஓசோன் அடுக்கு ஆகும், இது ஸ்ட்ரடோ அடுக்கில் இருந்துகொண்டு பூமியின் மேற்பரப்பை புற ஊதா கதிர்களிடமிருந்து பாதுகாக்கிறது. பூமியின் மேற்பரப்பிலிருந்து 100 கி.மீ. தொலைவில் உள்ள கார்மன் கோடு வளிமண்டலத்திற்கும் விண்வெளிக்கும் இடையே உள்ள எல்லையை நிர்ணயிக்கிறது.

வெப்ப ஆற்றலால், வளிமண்டலத்தின் வெளி விளிம்பில் உள்ள சில மூலக்கூறுகளின் வேகம் அதிகரித்து ஒரு சமயம் அவை புவியின் ஈர்ப்பு சக்தியிலிருந்த விடுபடுகின்றது. இதன் விளைவாக நிதானமாக அதே சமயம் நிலையாக வளிமண்டலம் விண்வெளியில் நுழைகிறது. ஏனெனில், நிலையற்ற ஹைட்ரஜன் மூலக்கூறு நிறை குறைவாக இருப்பதால், அது மிக விரைவிலேயே விடுபடும் வேகத்தை அடைகிறது. மேலும் மற்ற வாயுக்களை விட மிக வேகமாக விண்வெளிக்குள் நுழைகிறது. இதுவே பூமி ஆரம்ப ஒடுக்க நிலையிலிருந்து தற்போதைய ஆக்சிஜனேற்ற நிலையை அடைவதற்கு காரணமாகும். ஒளிச்சேர்க்கை ஆக்சிஜன் மிகுதியாக கிடைக்க வழி செய்கிறது. அதே சமயத்தில், ஒடுக்கும் காரணியான ஹைட்ரஜன் குறைவதற்கும் காரணமாகிறது. வளிமண்டலத்தில் ஆக்சிஜன் அதிகமாக பரவுவதற்கு இதுவே காரணமாக இருந்திருக்கும் என நம்பப்படுகிறது.
எனவே, பூமியின் வளிமண்டலத்திலிருந்து வெளியேறக்கூடிய ஹைட்ரஜனின் தன்மை, பூமியில் வாழ்க்கையின் முன்னேற்றத்திற்கு வழி வகுத்திருக்கிறது. தற்போதைய ஆக்சிஜன் நிறைந்த வளிமண்டலத்தில், ஹைட்ரஜன் வளிமண்டலத்தை விட்டு வெளியேறும் முன்னரே, நீராக மாற்றப்படுகிறது. அதற்கு பதிலாக, வளிமண்டலத்தின் மேல்பகுதியில் ஏற்படும் மீத்தேனின் அழிவே, ஹைட்ரஜன் இழப்பிற்கு காரணமாகிறது.

 காந்தப்புலம்
thumbnail|right|300px|புவியின் காந்தப்புலம், இருதுருவங்களை ஒத்திருக்கிறது.
புவியின் காந்தப்புலத்தின் காந்த இரு துருவங்கள், அதன் இரு புவியியல் துருவங்களுக்கு அருகில் தற்போது அமைந்திருப்பதாக தோராயமாக கருதப்படுகிறது. இயக்கவியல் கொள்கையின்படி, காந்தப்புலமானது, பூமியின் உருகிய நிலையில் உள்ள வெளிக்கருவில், வெப்பம் கடத்தும் பொருள்களின் கடத்துத் திறனை உருவாக்கி மின்சாரத்தை உற்பத்தி செய்யும் இடத்தில், உருவாக்கப்படுகிறது. இதுவே, பூமியின் காந்தப்புலத்தை உருவாக்குகிறது. வெளிக்கருவில், வெப்ப கடத்துத் திறன் ஒழுங்கற்ற நிலையில் இருக்கும். மேலும், அது அவ்வப்போது மாறிக்கொண்டேயிருக்கும். இந்த காந்தப்புல மாற்றம் ஒவ்வொரு மில்லியன் வருடத்திற்கு சில முறை ஒழுங்கற்ற இடைவெளியில் மாறிக்கொண்டேயிருக்கும். இறுதியாக இந்த மாற்றம் 700,000 வருடங்களுக்கு முன் நிகழ்ந்தது.

இந்த புலமானது காந்த அடுக்கை (magnetosphere) ஏற்படுத்தி, சூரியக் கதிர் காற்றுக்கு அருகில் உள்ள துகள்களை விலக்குகிறது. சூரிய கதிரின் பௌ ஷாக் (bow shock) நுனி புவியின் ஆரத்தை போன்று 13 மடங்கைக் கொண்டது. காந்தப்புலதிற்கும் சூரிய காற்றுக்கும் நிகழும் மோதலினால் வான் ஆலன் கதிர்வீச்சு வளையம் உண்டாகிறது. அது பொது மையமாகக்கொண்ட, டாரஸ் (torus) வடிவமுள்ள மின்னூட்டதுகள்கள் கொண்ட பகுதியாகும். பிளாஸ்மா புவியின் வளிமண்டலத்தில் காந்த துருவங்களில் நுழையும்போது கனல் (அரோரா) ஆக மாறுகிறது.

 பூமியின் கோளப்பாதை மற்றும் சுழற்சி
 சுழற்சி
thumbnail|right|280px|புவியின் சாய்ந்த அச்சுக்கும் (அல்லது சாய்நிலை) அதன் சுழலும் அச்சு மற்றும் கோளப்பாதைக்கும் இடையே உள்ள தொடர்பு.
பூமியின் சுழலும் காலம் சூரியனை ஒப்பிடுகையில்-அதன் சராசரி சூரிய நாள்-அதாவது சராசரி சூரிய நேரத்தில் 86,400 விநாடிகளாகும். இந்த ஒவ்வொரு வினாடியும் எஸ்.ஐ (SI) முறை வினாடியை விட சிறிது கூடுதல். ஏனெனில் 19 ஆம் நூற்றாண்டை ஒப்பிடும் போது தற்போதைய பூமியின் சூரிய நாள் அலை முடுக்கத்தால் சிறிதே நீண்டிருக்கிறது.

புவியின் சுழற்சிக் காலத்தை நிலையான விண்மீன்களுடன் ஒப்பிடுவதை, அதன் ஸ்டெல்லர் நாள் என சர்வதேச புவி சுழற்சி மற்றும் ஒப்பிடு காரணி அமைப்பு (IERS) கூறுகிறது, இது சராசரி சூரிய நேரத்தில் (UT1)  அல்லது இந்த எண்களின் மூலத்தில், "சராசரி சூரிய நேர நிமிடங்கள்" என்பதற்குப் பதிலாக "UT1 நிமிடங்கள்" என்ற சொற்றொடர் பயன்படுத்தப்பட்டுள்ளது.— பூமியின் சுழற்சிக் காலத்தை அதன் ஈர்ப்பு விசையால் உந்தப்பட்ட மாற்றம் அல்லது சராசரி வெர்னல் இஃகுவினாக்ஸ் உடன் ஒப்பிடுவதை, ஒரு விண்மீன் நாள் என தவறாக பெயரிடப்பட்டது, இது  சராசரி சூரிய நேரம் (UT1) ஆகும். எனவே ஒரு விண்மீன் நாள் ஸ்டெல்லர் நாளை விட 8.4 ms. சிறியது. SI நிமிடங்களில் 1623–2005—இறுதியில் உள்ள வரைபடம். மற்றும் 1962–2005 காலங்களுக்கு சராசரி சூரிய நேரம் IERS -லிருந்து கிடைக்கப் பெறும்.

வளிமண்டலத்துள் விண் கற்கள் (meteor) தாழ் சுழற்சி விண்கலங்கள் மற்றும் அனைத்து விண்ணுலக பொருட்களையும் பூமியின் மீதிருந்து பார்க்கும் போது மேற்கு நோக்கி மணிக்கு 15° = நிமிடத்திற்கு 15' என்ற அளவில் போவது போல் தோன்றும். இந்நகர்தல் இரு நிமிடத்தில் சூரியன் அல்லது சந்திரன் அடையும் விட்டமாகும்; நம் கண்களுக்கு சூரியனும் சந்திரனும் ஒரே அளவினவாகத் தோன்றும்.—சூரியன் மற்றும் சந்திரன் பக்கங்களில் உள்ள விட்டத்தைப் பார்க்கவும்.

 கோளப்பாதை
பூமி சூரியனைச் சுற்றி தன் கோளப்பாதையில் சராசரியாக 365.2564 சூரிய நாட்களில் 150 மில்லியன் கி.மீ. அல்லது ஒரு விண்மீன் ஆண்டை (sidereal year) கடக்கின்றது. இதனால் சூரியன், நட்சத்திரங்களை ஒப்பிடுகையில் கிழக்கு நோக்கி நாளொன்றுக்கு 1° நகர்வதாக அல்லது சூரியன் அல்லது சந்திரன் விட்டத்தை 12 மணி நேரத்தில் கடப்பதாகத் தோன்றுகிறது. இந்தச் செயலால் சராசரியாக ஒரு சூரிய நாள் அல்லது 24 மணி நேரத்தில் பூமி தன் அச்சிலேயே ஒருமுறை சுழன்று சூரியன் அதன் ஆரம்ப நிலை மெரிடியனை வந்தடைகின்றது. பூமி தன்னைத்தானே விநாடிக்கு 30 கி.மீ. (மணிக்கு 108,000 கி.மீ.) வேகத்தில் சுழல்கிறது, இது பூமியின் விட்டத்தை (ஏறத்தாழ 12,600 கி.மீ.) ஏழு நிமிடங்களிலும், சந்திரனுக்கு செல்லும் தூரத்தை (384,000 கி.மீ.) நான்கு மணி நேரத்திலும் கடக்க ஏதுவான வேகமாகும்.

சந்திரன் பூமியுடன் சேர்ந்து பொதுவான ஒரு பேரி மையத்தை (barycenter), அதன் பின் காணப்படும் விண்மீன்களை ஒப்பிடுகையில் 27.32 நாட்களில் சுழன்று வருகிறது. சூரியனைச் சுற்றி, பூமி மற்றும் சந்திரன் ஆகியவற்றின் பொதுவான சுழற்சியைச் சேர்த்தால், சைனோடிக் மாத காலமாகும், பௌர்ணமியிலிருந்து பௌர்ணமி வரை 29.53 நாட்களாகும். விண்வழி வட துருவத்திலிருந்து காணும் போது பூமி, சந்திரன் மற்றும் அவற்றின் அச்சு சுழற்சி, எதிர்மறை சுழற்சியாக தோன்றும். பூமி மற்றும் சூரியன் ஆகியவற்றின் வட துருவத்திலிருந்து காணும் போது பூமி சூரியனை எதிர்மறையாக சுழன்று வருவது தெரியும். பூமியின் கோளப்பாதையும் அச்சுத் தட்டும் ஒன்றி அமையவில்லை: பூமி சூரிய தட்டின், செங்குத்தான கோட்டிலிருந்து 23.5 கோணங்கள் பூமியின் அச்சு சாய்ந்து காணப்படுகிறது மற்றும் பூமி சந்திரன் தட்டு பூமி சூரிய தட்டிலிருந்து ஐந்து கோணங்கள் பெயர்ந்து உள்ளது. இந்தச் சாய்வான அமைப்பு இல்லையென்றால் சந்திர கிரகணமும் சூரிய கிரகணமும் இருவாரங்களுக்கு ஒருமுறை ஏற்படும் அமைப்பு இருக்கும்.

ஹில் அடுக்கு (Hill sphere) அல்லது புவியீர்ப்பு அடுக்கு பூமியிலிருந்து 1.5 கிகா மீட்டர் (அல்லது 1,500,000 கிலோமீட்டர்கள்) ஆரமுடையதாகும்.புவிக்கு, ஹில் ஆரம் என்பது

,
m என்பது புவியின் நிறை, a என்பது வானியல் அலகு மற்றும் M என்பது சூரியனின் நிறை. A.U. வில் உள்ள ஆரம்:

. பூமியின் புவியீர்ப்பு விசை மற்ற விண் பொருட்களாகிய சூரியன் மற்றும் மற்ற கிரகங்களின் ஈர்ப்பு விசையை விட அதிகமாக இருக்கும் மற்றும் அதிகபட்ச தொலைவில் இருக்கும் இடமுமாகும். பூமியின் கட்டில் இருக்கும் அனைத்து பொருட்களும் இந்த தொலைவுக்குள் இருக்க வேண்டியது அவசியம் மீறினால் அவை சூரியனின் ஈர்ப்பு விசையினால் பூமியை விட்டு வெளியேறி விடும்.

thumbnail|சூரியனின் இடத்தைக் காட்டும், பால்வெளி மண்டல விளக்கப்படம்.

பூமி சூரிய மண்டலத்தோடு பால்வெளி (Milky Way) கேலக்ஸியில் (galaxy) அதன் மையத்தை 28,000 ஒளி ஆண்டுகளில் சுழலும் பாதையில் அமைந்துள்ளது. இது தற்போது இந்த மண்டலத்தின் நில நடுதட்டிலிருந்து (equatorial plane) 20 ஒளி ஆண்டுகள் மேலேயும் ஓரியன் மண்டலத்தின் சுழல் கையிலும் (Orion spiral arm) அமைந்துள்ளது.

 பூமி அச்சின் சாய்வும் காலங்களும்
பூமியின் அச்சு சாய்ந்திருப்பதால், பூமியின் மேற்பரப்பில் விழும் சூரிய ஒளியின் அளவு வெவ்வேறு இடங்களில் பெரிதும் வேறுபடுகின்றது. இது பல காலம் சார்ந்த தட்பவெப்பநிலை மாற்றங்களை, ஏற்படுத்துகின்றது, வடதுருவம் சூரியனை நோக்கி உள்ள போது வட கோளார்தத்தின் கோடை காலமும், அதுவே சூரியனை விட்டு விலகி உள்ள போது குளிர்காலமாகவும் ஏற்படுகின்றது. கோடை காலத்தின் நாட்கள் நீண்டும் சூரியன் வானில் உயரேயும் காணப்படுகின்றது. குளிர் காலத்தில், தட்பவெப்ப நிலை பொதுவாக குளிர்ச்சியாகவும் மற்றும் நாட்கள் குறுகியும் காணப்படும். ஆர்க்டிக் வளையத்திற்கு மேல் ஓர் அதீதமான செயல் காணப்படுகின்றது, அங்கே வருடத்தின் ஒரு பகுதி காலத்தில் வெளிச்சமே இருப்பதில்லை - இது துருவ இரவு என்றழைக்கப்படுகின்றது. தென் துருவம் வடதுருவத்திற்கு எதிர்புறம் அமைந்திருப்பதால், தென் கோளார்த்த காலங்கள் வட கோளார்த்த காலங்களுக்கு எதிர்மறையாக அமைந்திருக்கிறது.

200px|thumbnail|left|செவ்வாயிலிருந்து புவி மற்றும் சந்திரன், செவ்வாய் உலக ஆய்வாளரால் எடுக்கப்பட்ட படம். விண்வெளியிலிருந்து காணும் போது, சந்திரன் வெவ்வேறு தோற்றங்களை பெறுவதைப் போல பூமியும் மாறுபட்ட தோற்றங்களை பெறுவதைக் காணலாம்.
வானியல் மரபுப்படி, நான்கு பருவ காலங்களும், புவி தனது கோளப் பாதையில் சூரியனை நோக்கி அல்லது சூரியனிலிருந்து விலகும் அதிகபட்ச அச்சு சாய்வுப் புள்ளியான சால்ஸ்டிஸ் (solstice) என்பதையும், இஃவினாக்ஸ் (equinox) சாயும் திசை சூரியனை நோக்கிச் செங்குத்தாக இருக்குமானால், இவை இரண்டையும் வைத்து நிர்ணயிக்கப்படுகிறது. குளிர் கால சால்ஸ்டிஸ் டிசம்பர் 21 அன்று ஏற்படும், கோடை கால சால்ஸ்டிஸ் ஜூன் 21 தேதி வாக்கில் ஏற்படும், வசந்தகால இஃவினாக்ஸ் மார்ச் 20 ஆம் தேதி வாக்கில் ஏற்படும், இலையுதிர்கால இஃவினாக்ஸ் செப்டம்பர் 23 ஆம் தேதி வாக்கில் ஏற்படும்.

புவியின் சாய்வு கோணம் பல காலங்களுக்கு நிலையாக இயங்கக்கூடியது. இருப்பினும் இந்தச்சாய்வும் சிறிதளவு ஒழுங்கற்ற இயக்கம் (nutation) கொண்டிருக்கிறது, அதாவது மிகச்சிறிய ஒழுங்கற்ற இயக்கம் 18.6 ஆண்டுகளில் ஏற்படுகின்றது. புவி அச்சின் நிலையும் (கோணமல்லாது) காலவாக்கில் மாறுகின்றது, 25,800 ஆண்டு காலம் ஒரு முழு வட்டப்பாதையில், சிறிய ஆனால் தொடர்ச்சியான ஈர்ப்பு விசையால் உந்தப்பட்ட மாற்றத்துடன் (precessing) சுழன்று வருகிறது; இந்த மாற்றமே விண்மீன் ஆண்டு மற்றும் வெப்ப ஆண்டிற்கு இடையே உள்ள வேறுபாட்டிற்கான காரணமுமாகும். இந்த இரண்டு நகர்தலும் புவியின் நிலநடுக்கோட்டைச் சார்ந்த வீக்கத்தின் மீது சூரியன் மற்றும் சந்திரனின் வேறுபட்ட கவர்ச்சியினால் ஏற்படுகிறது. புவியிலிருந்து காணும் போது, துருவங்கள் கூட சில மீட்டர் தூரம் மேற்பரப்பில் நகர்கிறது. இந்த துருவ நகர்தல் பல சுழற்சி பகுதிகள் அடங்கியதாகும், இந்த பல பகுதிகள் மொத்தமாக பகுதி கால நகர்தல் என்றழைக்கப்படுகின்றது. இந்த நகர்தலுக்கு ஒரு வருட சுற்றோடு 14 மாத சுற்றும் உள்ளது, அதை சாண்ட்லேர் தள்ளாட்டம் என குறிப்பிடுகின்றனர். பூமியின் சுழல் வேகமும் தின நேர மாற்றம் என்ற செயலால் பாதிக்கப்படுகின்றது.

இந் நாட்களில் புவியின் சூரிய சிறும வீச்சு ஜனவரி மூன்றாம் தேதியும் சூரிய பெரும வீச்சு ஜூலை நான்காம் தேதியும் ஏற்படுகின்றது. இந்த நாட்கள் நிலையானதல்ல, இவை காலப்போக்கில் புவியின் சுழற்சியாலும் ஈர்ப்பு விசையால் உந்தப்பட்ட மாற்றங்களாலும் மாறிக்கொண்டே இருக்கின்றது மேலும் இது மிலன்கோவிட்ச் சுற்று எனும் சுழல் அமைப்பை பின்பற்றுகின்றது. சூரியன் மற்றும் பூமிக்கிடையே ஆன தூரம் அதிகமாகிக்கொண்டிருப்பதால் சூரிய சிறும வீச்சுக்கும் பெரும வீச்சுக்கும் இடையே பூமியை அடையும் கதிர் வீச்சில் 6.9% சூரிய பெரும வீச்சு, சூரிய சிறும வீச்சிலிருந்து 103.4% தூரத்தில் உள்ளது. இன்வர்ஸ் ஸ்குயர் விதியால், சூரிய சிறும வீச்சிலிருந்து வரும் கதிர்வீச்சு, சூரிய பெரும வீச்சிலிருந்து வரும் ஆற்றலிலிருந்து 106.9% மாக இருக்கும். வேறுபாடு உள்ளது. பூமி சூரியனின் மிக அருகே செல்லும் போது அதன் தென் துருவம் சூரியனை நோக்கி இருப்பதால் அதற்கு சூரிய சக்தி வட துருவத்தை ஒப்பிடுகையில் ஒரு வருடத்தில் அதிகமாகக் கிடைக்கின்றது. ஆனால் தென் துருவம் இந்த வகையில் அடையும் சக்தி அது புவி அச்சின் சாய்வு மற்றும் அதிக ஆற்றலை உறிஞ்சும் தென் துருவ நீரினால் கிடைக்கும் மொத்த சக்தியை விட மிக குறைவே ஆகும்.

 நிலா

+ சிறப்பியல்புகள்  விட்டம் 3,474.8 கி.மீ.2,159.2 mi நிறை 	 7.349கிகி8.1 (குறுகிய டன்கள்) அரை-முதன்மை அச்சு 384,400 கிமீ238,700 mi சுற்றிவரும் காலம் 27 நா 7 ம 43.7 நி

சந்திரன் பூமியை விட பெரிய, நிலம் சம்பந்தப்பட்ட, செயற்கைக்கோள் போன்ற ஒரு கோளாகும், இதன் விட்டமானது பூமியின் விட்டத்தைப் போன்று கால் மடங்கு பெரியதாகும். அதன் கோளோடு ஒப்பிடுகையில் சந்திரன்தான் சூரியக் குடும்பத்திலேயே மிகப் பெரியதாகும். (சாரன் (Charon) என்பது சிறிய கோளான ப்ளூடோவை விட பெரியதாகும்) மற்ற கோள்களைச் சுற்றி வரும் இயற்கையான செயற்கைக்கோள்கள் பூமியினுடையதைப் போலவே "சந்திரன்கள்" என்று அழைக்கப்படுகின்றன.

புவிக்கும் சந்திரனுக்கும் இடையே உள்ள புவிஈர்ப்பு சக்திதான் புவியில் பேரலைகள் உண்டாகக் காரணமாக இருக்கிறது. இதுவே சந்திரனில் பேரலை நிறுத்தத்திற்கும் காரணமாகிறது: இதன் சுழற்சிக் காலமானது அது பூமியைச் சுற்றி வரும் காலத்திற்குச் சமமாகும். இதன் காரணமாகவே, இது பூமிக்கு எப்பொழுதும் ஒரே பகுதியைக் காட்டுகிறது. சந்திரன் பூமியைச் சுற்றி வருவதால், அதன் வெவ்வேறு பகுதிகள் சூரியனால் ஒளிரச் செய்யப் படுகின்றன. மேலும், இது சந்திரனின் முகங்களைக் காட்டுகிறது; சந்திரனின் இருள் பகுதிகள் ஒளிர்கின்ற பகுதியிலிருந்து சூரியனின் ஒளிக்கற்றைகளால் பிரிக்கப்படுகிறது.

இந்தப் பேரலைகள் ஊடாடுவதன் காரணமாக, சந்திரன் பூமியை விட்டு வருடத்திற்கு 38 மி.மீ. விலகிச் செல்கிறது. பல மில்லியன் வருடங்களுக்கு மேலாக, இந்த சிறு மாற்றங்களும்-ஒரு வருடத்திற்கு 23 µs வீதம் பூமியின் ஒரு நாள் நீள்வதும், பல குறிப்பிடத்தகுந்த மாற்றங்களை ஏற்படுத்தியுள்ளன. எடுத்துக்காட்டாக, தேவோனியன் காலத்தின் பொழுது, (தோராயமாக 410 மில்லியன் ஆண்டுகளுக்கு முன்) ஒரு வருடத்திற்கு 400 நாட்களும், ஒரு நாளுக்கு 21.8 மணிநேரமுமாக இருந்தது.

பூமியின் தட்பவெப்பநிலையை மாற்றுவதன் மூலம் சந்திரன் பூமியில் வாழ்க்கையின் முன்னேற்றத்தை பெரிதும் பாதித்திருக்கிறது. தொல்லுயிர் ஆராய்ச்சியின் முடிவுகளும் மற்றும் கணினியின் மாதிரிகளும் பேரலைகளுக்கு சந்திரனுடன் உள்ள கவர்ச்சியினால்தான் பூமியினுடைய அச்சின் சாய்வு நிலையாக உள்ளது என்பதை நமக்கு காட்டுகிறது. சூரியனும் இதர கோள்களும் பூமியின் நிலநடுக்கோட்டைச் சார்ந்த வீக்கத்திற்கு கொடுக்கும் உந்து அழுத்தத்திற்கு எதிராக இந்த நிலைப்புத்தன்மை இல்லையெனில் பூமியின் சுழலும் அச்சு ஒரு நிலையிலன்றி குழப்பமானதாக இருந்திருக்கும், மேலும் செவ்வாய் கோளில் நடப்பதைப் போல மில்லியன் வருடங்களுக்கு மேல் நிலைமாறான மாற்றங்களை ஏற்படுத்தியிருக்கும் என சில கொள்கையாளர்கள் நம்புகிறார்கள். பூமியின் சுழலும் அச்சு நீள்வட்டப்பாதையை அடைய நேர்ந்தால் உயர்ந்தபட்ச காலநிலை மாறுபாடுகளினால் உயர்ந்தபட்ச மோசமான தட்பவெப்ப நிலையை எதிர்கொள்ள வேண்டியிருக்கும். ஒரு துருவம் கோடைக்காலத்தில் சூரியனை நோக்கியும் குளிர்காலத்தில் சூரியனுக்கு எதிர் திசையிலும் அமைந்திருக்கும். இதனை ஆராய்ந்த வான் கோள் அறிவியலாளர்கள் இது எல்லா பெரிய விலங்குகளையும் மற்றும் உயர்ந்த தாவரங்களையும் அழிக்கக்கூடும் என கருதுகின்றனர். எனினும் இது ஒரு சர்ச்சைக்குரிய கருத்தாகும், மேலும் பூமியைப் போலவே சுழற்சியையும் சுழலும் காலத்தையும் உடைய ஆனால் பெரிய சந்திரனும் திரவ உட்கருவும் இல்லாத செவ்வாய் கோளை பற்றிய ஆராய்ச்சி இதற்கு ஒரு தீர்வைக் கொடுக்கலாம்.

பூமியிலிருந்து பார்க்கும்பொழுது, சந்திரன் வெகு தொலைவில் இருப்பது போலவும் சூரியனைப் போன்றே சிறிய கோள வடிவத்திலும் காட்சியளிக்கிறது. இந்த இரண்டின் கோண அளவும் (அல்லது திட கோணம்) ஒத்திருக்கிறது ஏனெனில், சூரியனுடைய விட்டம் சந்திரனுடையதைப் போல 400 மடங்கு பெரியதாக இருந்தாலும், அது சந்திரனை விட 400 மடங்கு அதிக தொலைவிலும் இருக்கிறது. இது பூமியில் முழு மற்றும் வருடாந்திர கிரகணம் ஏற்பட காரணமாகவும் இருக்கின்றது.

thumbnail|center|800px|புவி மற்றும் சந்திரனுக்கு இடையிலான தூரத்தின் அளவீட்டு மாதிரி

சந்திரனின் தோற்றம் பற்றிய உலகம் முழுதும் ஏற்றுக்கொள்ளப்பட்ட பெருந்தாக்க விதியின்படி (giant impact), செவ்வாயின் அளவை ஒத்த தேயியா (Theia) எனப்படும் மாதிரி கோளும் ஆதிகால பூமியும் மோதிக்கொண்டதனால் ஏற்பட்டது. இந்தக் கூற்றின்படி (மற்றவைகளுடன்) சந்திரனில், பூமியை ஒப்பிடுகையில் குறைந்த அளவு இரும்பு மற்றும் ஆவியாகக்கூடிய தனிமங்கள் இருப்பதும் மற்றும் அதனுடைய கட்டமைப்பு ஏறக்குறைய பூமியின் மேலோட்டை ஒத்திருப்பதும் தெளிவாகத் தெரிகிறது.

பூமிக்கு குறைந்தது இரண்டு துணை-சுற்று பெரு விண்கற்கள், 3753 க்ருதினே மற்றும் 2002 AA29 என இருக்கிறது.

 புவியில் உயிர்களின் புழக்கம்
ஒரு கோள், உயிர்களை தக்க வைத்துக் கொள்ளுமானால் உயிர்கள் அங்கே தோன்றாவிடினும் அது உயிர்கள் புழங்கத்தக்கதாக கருதப்படுகிறது. பூமி (தற்போதைய கூற்றுகளின் படி) உயிர்கள் வாழ்வதற்கு வேண்டிய திரவ நீர், சுற்றுச் சூழலில் கடினமான உயிர் வேதியல் மூலக்கூறுகள் உருவாகும் தன்மை மற்றும் வளர்ச்சிதை மாற்றத்திற்கு தேவையான சக்தி ஆகியவற்றைப் பெற்றிருக்கிறது. பூமி சூரியனிலிருந்து உள்ள தூரம், அதன் சுழற்சியில் காணப்படும் முரண், சுழலும் வேகம், அச்சுச் சாய்வு, புவியின் வரலாறு, வளிமண்டல தக்க வைத்துக் கொள்ளல் மற்றும் பாதுகாக்கும் காந்தப்புலன் இவையாவும் இந்த கிரகத்தில் உயிர்கள் உருவாக மற்றும் தக்க வைத்துக் கொள்ள காரணிகளாகச் செயல்பட்டுள்ளன.

 உயிர்க்கோளம்
புவியின் உயிர்கள் சேர்ந்து அதன் "உயிர்க்கோள"த்தை அமைக்கின்றது. இந்த உயிர்க்கோளம் பூமியில் 3.5 மில்லியன் வருடங்களுக்கு முன் உருவாகி பரிணாம வளர்ச்சி அடையத் தொடங்கியது. அண்டத்தில் பூமியில் மட்டுமே உயிர்கள் இருப்பதாக தற்போது நாமறிவோம். சில அறிவியலாளர்கள் பூமியைப் போன்ற உயிர்க்கோளம் அரிதானது என நம்புகின்றனர்.

இந்த உயிர்க் கோளம் பல உயிர்க்கட்டுகளாக பிரிக்கப்பட்டுள்ளது, அதாவது ஒத்த தாவர மற்றும் விலங்கு வகைகளை வைத்து பிரிக்கப்பட்டுள்ளது. நிலத்தில் நிலநீர்க்கோடு மற்றும் கடல் மட்டத்திற்கு மேல் உள்ள உயரம் இரண்டும் உயிர்க்கட்டுகளைப் பிரிக்கிறது. ஆர்க்டிக், அண்டார்க்டிக் வளையங்களுக்குள் அல்லது அதிக உயரமான இடங்களிலும் காணப்படும் நில உயிர்க்கட்டுகளில் மிக அரிதாகவே தாவரங்களும் விலங்குகளும் காணப்படுகின்றன, ஆனால் பூமத்திய ரேகை அருகே காணப்படும் உயிர்க்கட்டில் நீண்ட பலவகை உயிரினங்கள் காணப்படுகின்றன.

 இயற்கை வளங்கள் மற்றும் நிலம் பயன்பாடு

பூமி, பயனுள்ள பல நோக்கங்களுக்காகப் பயன்படுத்தும் வகையில் பல வளங்களை மனிதனுக்கு அளிக்கிறது. இவற்றில் சில புதுப்பிக்க இயலாத வளங்கள் (non-renewable), அதாவது தாது எரிபொருள் போன்றவை குறுகிய காலத்தில் உருவாவதில்லை.

அதிக அளவிலான தொல்லுயிர் படிம எரிபொருட்கள் பூமியின் மேலோட்டிலிருந்து கிடைக்கின்றது, அவை நிலக்கரி, பெட்ரோல், இயற்கை வாயு மற்றும் மீத்தேன் கிளாத்ரேட்டுகளாம். இந்த எரிபொருட்களை ஆற்றல் உருவாக்குதலுக்கும், வேதி பொருட்கள் உருவாக்க முன்னோடியாகவும் பயன்படுத்தப்படுகிறது. பூமியின் மேலோட்டில் கனிம தாதுக்கள் படிமங்களாக தாது உருவாக்கல் மூலம் மற்றும் அரித்தல், பலகை டெக்டோனிக் மூலம் உருவாகி படிந்துள்ளன. இவை உலோகம் மற்றும் உபயோகமுள்ள தனிமங்கள் உருவாக்குவதற்கு ஒருநிலைப்பட்ட மூலமாக பயன்படுத்தப்படுகிறது.

புவியின் உயிர்க்கோளம் மனிதனுக்குத் தேவையான பல உயிர் பொருட்களை உருவாக்குகின்றது, இவை உணவு, மரம், ஆக்சிஜன், மருந்துப் பொருட்கள் மற்றும் உயிர்க்கழிவுகளின் மறுசுழற்சி ஆகியவையாகும். நில ஆதாரமான சூழலமைப்பு மேல்மண் மற்றும் தூயநீரை சார்ந்தும் மற்றும் கடல் சூழலமைப்பு நிலத்திலிருந்து கரைந்து கடலை அடையும் ஊட்ட பொருட்களைச் சார்ந்தும் உள்ளது. மனிதர்களும் நிலத்தில் கட்டுமானப் பொருட்களைக் கொண்டு குடில்கள் அமைத்து வாழ்கின்றனர். 1993 கணக்கெடுப்பின் படி, மனிதர்கள் உபயோகப்படுத்தும் நிலம் தோராயமாக:

நில உபயோகம்விழுக்காடு விவசாயம்: 13.13% நிலையான பயிர்: 4.71% நிலையான மேய்ச்சல் நிலம்: 26% காடுகள் மற்றும் வனப்பகுதி: 32% நகரங்கள்:  1.5% மற்றவை: 30%

1993 ஆம் ஆண்டு கணக்கெடுப்பின் படி விவசாயம் செய்யப்படும் நிலம் 2,481,250 சதுர கி.மீ.

 இயற்கை மற்றும் சுற்றுச் சூழல் அபாயம்
பூமி மீதுள்ள பல இடங்கள் அதீதமான வானிலையால் அதாவது புயல், சூறாவளி, சுழல்காற்று ஆகியவற்றால் பாதிப்படைகின்றன. மேலும் பல இடங்களில் நில நடுக்கம், நில சறுக்கம், ஆழிப் பேரலைகள், எரிமலைகள், சுழற்காற்று, புதைகுழிகள், பனிப்புயல், வெள்ளம், வறட்சி மற்றும் விபத்துகளும் பேரழிவுகளும் ஏற்படுகின்றன.

பல இடங்களில் மனிதனால் உருவாக்கப்பட்ட சுற்றுப்புற மாசு, காற்று மற்றும் நீரை பாதித்ததோடல்லாமல், அமில மழை, நச்சுப்பொருட்கள், பயிரழித்தல் (மிகையான மேய்ச்சல், காட்டை அழித்தல், பாலைவனமாக்கல்), வன உயிர்கள் அழித்தல், உயிரினங்களின் மறைவு, மண் அழிப்பு, மண் மறைவு, மண் அரிப்பு மற்றும் ஆக்கிரமிக்கும் உயிரினங்களை அறிமுகப்படுத்தல் போன்றவற்றையும் ஏற்படுத்தியுள்ளது.

ஒரு அறிவியல் அமைப்பு மனிதனால் ஏற்படுத்தப்பட்ட தொழிற்சாலைகளிலிருந்து வெளிவரும் கரியமில வாயுவினால் கோள வெதும்பல் ஏற்பட்டுள்ளதாக கூறுகிறது. இதனால் பனிக்கட்டியாறு மற்றும் பனிக்கட்டி மலை (ice sheet) உருகுதல், அதீதமான வெப்பநிலை மாற்றங்கள், வானிலையில் குறிப்பிடத்தக்க மாற்றங்கள் மற்றும் கடல் மட்ட அளவு உயருதல் போன்ற இயற்கைச் சீற்றங்கள் ஏற்படும் எனக் கண்டறிந்துள்ளனர்.
பூமியின் மேல் வளிமண்டலத்தில் மனிதனால் அனுப்பப்பட்ட செயற்கைக்கோள்களில் 3,000 தான் தற்சமயம் இயங்கிக்கொண்டிருக்கின்றன. ஆனால் இதுவரை 8,000 செயற்கைக்கோள்களை உலக நாடுகள் அனுபிவைத்துள்ளன. இவை அனைத்தும் பூமிக்கு மேலே 250 கிலோ மீட்டர் முதல் 850 கிலோ மீட்டர்கள் உயரத்தில் சுற்றிக்கொண்டு இருக்கின்றன.விண்வெளி? இந்து தமிழ் பார்த்த நாள் ஏப்ரல் 22 2015 புதன்

 மனிட புவியியல்

வரைபடவியல், வரைபடங்களைப் பற்றி அறிந்து, அவற்றை உருவாக்கும் முறை மற்றும் புவியியல் இவை இரண்டும் புவியை வரையறுக்க உதவியாய் இருந்தன. ஆய்வின் மூலம் இடங்கள் மற்றும் தூரங்களை தீர்மானிப்பதும் மற்றும் சிறு அளவில் பயண திசை தீர்மானம் செய்தல், மேலும் ஒன்றின் நிலையையும் அதன் திசையும் கண்டறிதல் யாவும் வரைபடவியல் மற்றும் புவியியலோடு சேர்ந்து வளர்ந்து தேவையான மற்றும் பொருந்தக்கூடிய விளக்கங்களை அளித்திருக்கின்றது.

நவம்பர் 2008 ஆம் ஆண்டு கணக்கெடுப்பின் படி புவியில் 6,740,000,000 மனிதர்கள் வாழ்கின்றனர். உலக மக்கள் தொகை 2013 ஆம் ஆண்டுக்குள் 7 பில்லியனை எட்டும் எனவும் 2050 ஆம் ஆண்டுக்குள் 9.2 பில்லியனை எட்டும் எனவும் நம்பப்படுகிறது. இந்த வளர்ச்சி வளர்ந்து வரும் நாடுகளிலேயே ஏற்படும் என எதிர்பார்க்கப்படுகிறது. மக்கள் நெருக்கம் உலகில் வெவ்வேறு விதமாக உள்ளது, ஆனால் பெரும்பான்மையினர் ஆசியாவில் வாழ்கின்றனர். 2020 ஆம் ஆண்டிற்குள், உலக மக்கள் தொகையில் 60% மக்கள் கிராமபுரங்களில் அல்லாமல் நகரங்களில் வாழ்வார்கள் என எதிர்பார்க்கப்படுகிறது.

புவியின் மேற்பரப்பில் எட்டில் ஒரு பங்கு மட்டுமே மனிதன் வாழ உகந்ததாக கணக்கெடுப்பு காட்டுகின்றது மேலும் மூன்றில் ஒரு பங்கு நீராலும் மற்றும் நிலத்தில் பாதி பாலைவனமாகவோ,(14%) உயர்ந்த மலைகளாகவோ (27%), அல்லது குறைந்த தகுதி உடைய இடங்களாகவோ உள்ளன. புவியின் வடகோடியில் இருக்கும் நிரந்தர குடியிருப்பு கனடா நாட்டிலுள்ள நுனாவட் (Nunavut) மாகாணத்திலுள்ள, எல்லெஸ்மியர் தீவிலுள்ள (Ellesmere) அலர்ட் (Alert) நகரமாகும்.(82°28′N) அதே போன்று தென் கோடியில் இருக்கும் குடியிருப்பு, அண்டார்க்டிகாவில் தென் துருவத்திலிருக்கும், அமண்ட்சன் - ஸ்காட் தென் துருவ நிலையம் ஆகும். (90°S)

400px|right|thumbnail|புவியின் இரவுத் தோற்றம், DMSP/OLS என்ற சேர்மத்தின் உதவியால் இரவு நேர உலகின் மாதிரியை வடிவமைத்து எடுத்த நிலத்தின் ஒளிர்வு படம். இந்த படம் நிழற்படம் அல்ல, நேரடியாக பார்ப்பவருக்கு இதில் உள்ள பல அம்சங்கள் மிகவும் பிரகாசமாக காணப்படலாம்.

சுதந்திர ஏகாதிபத்ய நாடுகள் அன்டார்ட்டிகாவின் சில பகுதிகளைத் தவிர்த்து, பூமியின் மொத்த நிலப்பரப்பையும் ஆக்ரமித்துள்ளன. 2007 ஆம் ஆண்டின் படி பூமியில் 201 ஏகாதிபத்திய நாடுகள் உள்ளன இதில் 192 ஐக்கிய நாடுகளின் அங்கத்தினராக இருக்கும் நாடுகளும் அடங்கும். இதைத்தவிர 59 சார்ந்த இடங்களும், பல தனித்தியங்கும் இடங்களும் மற்றும் சர்ச்சைக்குரிய இடங்களும் இவற்றில் அடங்கும். புவியின் வரலாற்றில் அதன் மொத்த பரப்பும் ஓர் ஏகாதிபத்திய அரசின் கீழ் இருந்ததில்லை, ஆனால் பலமுறை பல நாடுகள் மொத்த உலக அதிகாரத்தையும் பெற முயற்சித்து தோல்வியுற்றுள்ளன.

ஐக்கிய நாடுகள் சபை உலகளாவிய அரசாங்கங்களுக்கிடையிலான அமைப்பு, இது நாடுகளுக்கிடையே ஏற்படும் கருத்து வேறுபாடுகளை போர்கள் மூலமல்லாது சுமுகமான முறையில் தீர்த்துக் கொள்ள நிறுவப்பட்டது. இருந்தாலும் இது ஓர் உலக அரசாங்கமன்று. ஐ.நா சபை சர்வதேச சட்டத்தை அளித்து, பொதுவான விதிகளைக் கடைபிடிக்கின்றது, மேலும் அங்கத்தினர்களால் ஒரு சேர தீர்மானிக்கும் போது ஆயுதமேற்றும் பிரச்சினைகளைத் தீர்க்கின்றனர், ஐநா சபை பெரும்பாலும் சர்வதேச அரசாங்க விவகாரங்களைத் தீர்ப்பதற்காகவே உருவாக்கப்பட்டது.

பூமியை சுற்றிய முதல் மனிதர் யூரி காகரின் ஆவார், இவர் ஏப்ரல் 12, 1961 அன்று இதைச் செய்தார். 2004ஆம் ஆண்டு வரை மொத்தம் 400 மனிதர்கள் வெளி அண்டத்திற்குச் சென்று மீண்டும் பூமியை அடைந்துள்ளனர், மேலும் இதில் அப்போலோ திட்டத்தின் கீழ் பனிரெண்டு பேர் சந்திரனில் நடந்துள்ளனர். பொதுவாக விண்வெளியில் வாழக்கூடிய மனிதர்களாக இருப்பவர்கள் சர்வதேச விண்வெளி மையத்தில் வசிப்பவர்கள் தான். இந்த மையத்தில் இருக்கும் மூன்று நபர்கள் ஆறு மாதங்களுக்கு ஒருமுறை மாற்றப்படுகின்றனர். இதுவரையில் பூமியிலிருந்து அதிகமான தூரத்தை மனிதர்கள் 1970 ஆம் ஆண்டில் அப்போல்லோ 13 விண்கலத்தில் பூமியிலிருந்து 400,171 கி.மீ. தூரத்தில் கடந்துள்ளனர்.

 கலாச்சார பார்வை
48px|left|🜨
thumbnail|right|விண்வெளி வீரர்களால் அப்போலோ 8-லிருந்து எடுக்கப்பட்ட முதல் "புவி உதய", நிழற்படம்
புவியின் வானியல் சின்னம் ஒரு வட்டத்தைச் சார்ந்த கூட்டல் குறியை உள்ளடக்கி இருந்தது.
தமிழில், ஆர்(பெரியது) →  தர் → தரை(terra) என்றாகும். மற்றும், ஓலா → உலா → நெலா → நிலா → நிலம் என்றும் ஆகும்.
புவியை ஒரு தெய்வமாக, குறிப்பாக ஒரு பெண் தெய்வமாக உருவகப்படுத்தி வழிபடுகின்றனர். பல கலாச்சாரத்தில் பெண் தெய்வத்தை, தாய் மண் என்று அழைப்பதோடு, மனித வள தெய்வமாக உருவகப்படுத்துகின்றனர். பல மதங்களின் படைப்பு இதிகாசங்களில் புவி உருவான வரலாறு பற்றி கூறும் போது புவி அதிக சக்தி வாய்ந்த ஒரு தெய்வம் அல்லது தெய்வங்களால் உருவாக்கப்பட்டதாக உள்ளது. பல்வேறு சமயப் பிரிவுகள், அடிப்படைவாத பிராட்டஸ்டண்ட் பிரிவினர் அல்லது இஸ்லாம் சமயத்தவர், புனித உரைகளில் படைப்பு இதிகாசத்தை பற்றிய தமது விளக்கங்கள் உண்மையானவை அவை உலகம் உருவான விதம் மற்றும் உயிர்களின் தோற்றம் மற்றும் வளர்ச்சி  பற்றிய அறிவியல் விளக்கங்களுடன் அல்லது அவற்றிற்கு பதிலாக அளிக்கப்பட வேண்டும் என வலியுறுத்துகின்றனர். இத்தகைய வாதங்களை அறிவியல் சமூகம்அறிவியல், பரிணாமம் மற்றும் படைப்பியல் தேசிய அகாடமி பிரஸ், வாஷிங்க்டன், டிசி 2005 மற்றும் மற்ற சமய குழுக்கள் எதிர்க்கின்றன. இதற்கு பிரபலமான எடுத்துக்காட்டு படைப்பு பரிணாம விவாதம்.

பண்டைய காலத்தில் பூமி தட்டையானது ; இதனையும் பார்க்கவும் காஸ்மஸ் இண்டிகோப்லூஸ்டஸ் (Cosmas Indicopleustes) என்ற நம்பிக்கை வெவ்வேறு நிலைகளில் நிலவியுள்ளது ஆனால் இதுவே மனிதன் உலகை சுற்றி வந்து பார்த்த பிறகு உலகம் உருண்டையானது தான் என்ற நிலைப்பாட்டை ஏற்படுத்தியது. விண்வெளி கலங்களில் வெளியே பறந்து அண்டத்திலிருந்து பூமியை பார்க்கும் போது அதன் பரிமாணம் வேறுபட்டதாய் தெரிந்தது, அதாவது தற்போது புவியின் உயிர்க்கோளம் என்பது உலகளாவிய நோக்கிலேயே கருதப்படுகின்றது.
இதன் பிரதிபலிப்பு வளரும் சுற்றுசூழ் பாதுகாப்பு அமைப்புகள் மனிதரால் புவிக்கு ஏற்படும் மாறுதல்கள் மற்றும் கேடுகளைப் பற்றி கவலையை வெளிப்படுத்தியுள்ளன.உதாரணத்திற்கு:

 குறிப்புகள்

 மேற்கோள்கள்

 ஆதார தொகுப்பு

 புற இணைப்புகள்
பூமிக்கு இவ்வளவு தண்ணீர் எங்கிருந்து வந்தது?
 விண்வெளி அதியசியங்கள்
 யுஎஸ்ஜிஎஸ் புவிகாந்தவியல் (Geomagnetism) திட்டம்
 நாசா (NASA) புவி கண்காணிப்பு மையம்
 நாசாவின் சூரிய அமைப்பு ஆய்வில் இருந்து புவி குறிப்பு
 பருவநிலை மாறுபாடு புவியின் உருவத்தில் மாறுபாட்டை ஏற்படுத்துகிறது - நாசா
 விண்வெளி வீரரின் புவி நிழற்பட நுழைவாயில்
 400 கோடி ஆண்டுகளுக்கு முன் சூரியனில் ஏற்பட்ட வெடிப்பே உயிர்கள் தோன்றக் காரணம்: நாசா

பகுப்பு:புவியியல்
பகுப்பு:நிலவியல்
*
பகுப்பு:புவியொத்த கோள்கள்

new:बँग्वारा

It is one of the greatest satellites in the sun's mountain in combination with light, full and sign. This universe, Telecom, Telecom, is used as the Blue Planet and the Blue Planet for the names of many images, because it is Levi (Australia) (Life).

The Incredible Year's 68 (The Incredible Year's 68) is a film of the New Year's Assistance and is a film of the New Year's Assistance.

கதிரவனிலிருந்து

ஒப்பிடுகையில்

பயன்படுத்தப்பட்டுள்ளது

Question: what is the name of the blue planet in the sun's mountain

It is one of the greatest satellites in the sun's mountain in combination with light, full and sign. This universe, Telecom, Telecom, is used as the Blue Planet and the Blue Planet for the names of many images, because it is Levi (Australia) (Life).

The Incredible Year's 68 (The Incredible Year's 68) is a film of the New Year's Assistance and is a film of the New Year's Assistance.

what is the name of the blue planet in the sun's mountain

Question: levi is the blue planet of which country

levi is the blue planet of which country

Question: what is the name of the blue planet

Question: what is the title of the film of the new year's assistance

what is the title of the film of the new year's assistance

Question: where is levi located

It is one of the greatest satellites in the sun 's mountain in combination with light , full and sign . This universe , Telecom , Telecom , is used as the Blue Planet and the Blue Planet for the names of many images , because it is Levi ( Australia ) ( Life ) .

The Incredible Year 's 68 ( The Incredible Year 's 68 ) is a film of the New Year 's Assistance and is a film of the New Year 's Assistance .

புவி (), கதிரவனிலிருந்து மூன்றாவதாக உள்ள கோள். விட்டம், நிறை மற்றும் அடர்த்தி கொண்டு ஒப்பிடுகையில் சூரிய மண்டலத்தில் உள்ள மிகப் பெரிய உட் கோள்களில் புவியும் ஒன்று. இதனை உலகம், நீலக்கோள் ,நீலக்கோள் என்பது பல படங்களின் பெயராக Blue Planet மற்றும் The Blue Planet என பயன்படுத்தப்பட்டுள்ளது, லைப் (பத்திரிக்கை) (Life) என்பதன் நம்பமுடியாத ஆண்டு '68 (The Incredible Year '68) என்ற இதழில் புவி உதயத்தின் படத்தை போடும் போது ஜேம்ஸ் டிக்கே என்ற கவியின் வரிகளாக Behold.

புவி (), கதிரவனிலிருந்து மூன்றாவதாக உள்ள கோள். விட்டம், நிறை மற்றும் அடர்த்தி கொண்டு ஒப்பிடுகையில் சூரிய மண்டலத்தில் உள்ள மிகப் பெரிய உட் கோள்களில் புவியும் ஒன்று. இதனை உலகம், நீலக்கோள் ,நீலக்கோள் என்பது பல படங்களின் பெயராக Blue Planet மற்றும் The Blue Planet என பயன்படுத்தப்பட்டுள்ளது, லைப் (பத்திரிக்கை) (Life) என்பதன்

நம்பமுடியாத ஆண்டு '68 (The Incredible Year '68) என்ற இதழில் புவி உதயத்தின் படத்தை போடும் போது ஜேம்ஸ் டிக்கே என்ற கவியின் வரிகளாக Behold.

It is one of the greatest satellites in the sun's mountain in combination with light, full and sign. This universe, Telecom, Telecom, is used as the Blue Planet and the Blue Planet for the names of many images, because it is Levi (Australia) (Life). The Incredible Year's 68 (The Incredible Year's 68) is a film of the New Year's Assistance and is a film of the New Year's Assistance.

It is one of the greatest satellites in the sun's mountain in combination with light, full and sign. This universe, Telecom, Telecom, is used as the Blue Planet and the Blue Planet for the names of many images, because it is Levi (Australia) (Life).

The Incredible Year's 68 (The Incredible Year's 68) is a film of the New Year's Assistance and is a film of the New Year's Assistance.

In the first verse of the Qur’an, the Qur’an was revealed in the first verse of the Qur’an, and the Qur’an was revealed in the first verse of the Qur’an.

So there are many of the survivors who have lived.

உயிர்க்கோளம்

குறிப்பிடும்

மாற்றியுள்ளது

How Many Species are There on Earth?
Abstract
This article surveys current answers to the factual question posed in the title and reviews the kinds of information that are needed to make these answers more precise. Various factors affecting diversity are also reviewed. These include the structure of food webs, the relative abundance of species, the number of species and of individuals in different categories of body size, along with other determinants of the commonness and rarity of organisms.
- Publication:
- Science
- Pub Date:
- September 1988
- DOI:
- 10.1126/science.241.4872.1441
- Bibcode:
- 1988Sci...241.1441M

Question: what is the first verse of the quran

In the first verse of the Qur’an, the Qur’an was revealed in the first verse of the Qur’an, and the Qur’an was revealed in the first verse of the Qur’an.

So there are many of the survivors who have lived.

Question: where is the qur'an revealed

Question: where is the qur'an revealed in the quran

உயிர்க்கோளம்

where is the qur'an revealed in the quran

In the first verse of the Qur’an , the Qur’an was revealed in the first verse of the Qur’an , and the Qur’an was revealed in the first verse of the Qur’an .

So there are many of the survivors who have lived .

அதுமுதல் புவியின் உயிர்க்கோளம் குறிப்பிடும் வகையில் அதன் வளிமண்டலம் மற்றும் உயிரற்ற காரணிகளை மாற்றியுள்ளது. அதனால் பல வளி சார்ந்த உயிரினங்கள் பெருகின.

அதுமுதல் புவியின் உயிர்க்கோளம் குறிப்பிடும் வகையில் அதன் வளிமண்டலம் மற்றும் உயிரற்ற காரணிகளை மாற்றியுள்ளது.

அதனால் பல வளி சார்ந்த உயிரினங்கள் பெருகின.

In the first verse of the Qur’an, the Qur’an was revealed in the first verse of the Qur’an, and the Qur’an was revealed in the first verse of the Qur’an. So there are many of the survivors who have lived.

In the first verse of the Qur’an, the Qur’an was revealed in the first verse of the Qur’an, and the Qur’an was revealed in the first verse of the Qur’an.

So there are many of the survivors who have lived.

The exhibition of the fountain is arranged in many end-of-the-art parts, or in a lot of detonical varieties.

It has been spotted for a few million years in the mining of the foam. About 71% of the foam has been spotted in the majority of the foam, but the other parts have been spotted in the sights, displays and all the lives.

அமைந்துள்ளது

மேற்பரப்பில்

பெருங்கடல்களாலும்

தீபகற்பங்கள்

உயிர்களுக்கும்

அதிமுக்கியமான

நிரப்பப்பட்டுள்ளது

PASADENA, Calif. - NASA’s Opportunity rover peeked over the rim of the crater in which it landed and was able to see the clamshell holder and parachute it discarded just before hitting the surface of Mars, scientists said Monday.
A color photograph from Opportunity, released at NASA’s Jet Propulsion Laboratory, showed the two objects distinctly, on a largely featureless surface.
|advertisement|
“There is the hardware that we’ve littered the surface with,” said Michael Malin, a member of the mission science team.
The rover was shielded by a clamshell-like device during its entry into the atmosphere of Mars.
The photograph, when combined with pictures taken from orbit, helped confirm exactly where Opportunity landed on Mars on Jan. 24. NASA planned for its orbiting Mars Global Surveyor satellite to begin looking for another Martian spacecraft, Britain’s ill-fated Beagle 2 lander, on Thursday.
NASA described the gray photograph shown Monday as an “approximate true-color image.” Mars’ iron-rich dust gives the planet its overall reddish color, but Opportunity landed in a relatively dust-free area.
Scientists likened Opportunity's landing to a hole-in-one by a golfer who cannot see the hole. Cushioned by airbags, the rover bounced and rolled across the Martian surface right into a 72-foot-wide (22-meter-wide) crater, where Opportunity has plenty of exposed bedrock in reach of its robotic geologic instruments.
NASA - JPL - Cornell - MSSS
The inset photo shows the Opportunity rover's backshell and parachute, as seen by the rover's panoramic camera. in which the rover sits. Scientists say Opportunity bounced 26 times after its landing and rolled to a stop in a small crater. The black-and-white photo, taken by the orbiting Mars Global Surveyor, is an aerial view of the debris (lower left) and the crater (upper right). The bright dot within the crater is Opportunity's landing platform.
Opportunity's first close-up images of the bedrock outcropping revealed fine-scale layering, with round beads of rock tucked within and scattered around the formation. Cornell University astronomer Steve Squyres, the mission's principal science investigator, compared the "spherules" to blueberries inside a muffin.
Scientists had three theories about the origin of the spherules, Squyres said. They could be:
- Droplets of molten rock, created during a volcanic eruption or a meteor impact, that hardened into spheres in midair.
- Concretions of minerals that accumulated when ground water percolated through layers of rock.
- Lapilli, or grains of volcanic ash that stuck together after an eruption.
Squyres said the lapilli explanation was the least likely of the three, since such beads are generally made of the same material they're embedded in. The Martian rock-berries, in contrast, appear to be made of material that's different from the bedrock layers.
"We think we should be able to test all of those" theories, Squyres said.
|FREE VIDEO|
|• Martian mystery novel|
Feb. 9: Cornell University astronomer Steve Squyres says unraveling the puzzles of Martian bedrock is like solving a mystery — and he shares the latest clues.
NASA
Over the next few days, Opportunity would roll along the length of the outcropping, now dubbed Opportunity Ledge. Along the way the rover would make a survey of the best spots for further study, Squyres said. Eventually, the rover will use its rock abrasion tool to grind away at the bedrock, then use its scientific instruments to determine the composition of the spherules as well as the surrounding rock matrix.
Just a few hours before Monday's news briefing, Opportunity's alpha proton X-ray spectrometer had completed an analysis of the bedrock's chemical composition, "and it has got a lot of sulfur in it," Squyres said. But he said it was too early to speculate on what that high sulfur content might mean.
Spirit moves on
Opportunity is just half of a two-rover, $820 million mission looking for geologic evidence that ancient Mars had liquid water long enough to allow for the development of life.
Opportunity's twin, the Spirit rover, is on the other side of the Red Planet, studying the rocks and soil of Gusev Crater. Over the weekend, Spirit's rock abrasion tool drilled a tenth of an inch (3 millimeters) into a pyramid-shaped basaltic rock named Adirondack and conducted a first-ever analysis of the rock's fresh interior.
All the evidence pointed toward Adirondack's volcanic origins — which meant the rock was unlikely to shed light on the liquid-water question. During its workday, Spirit moved on from Adirondack toward its next target, a stone called "White Boat."
Mobility software engineer Mark Maimone said the 21-foot (6.4-meter) drive was the "first test on Mars of the rover's autonomous navigation system." Engineers told Spirit where to drive, but the robotic rover decided on its own exactly how to get there.
Spirit had been stalled at Adirondack for more than two weeks due to a memory management glitch. Nevertheless, Maimone said Spirit's sprint briefly gave it the lead over Opportunity for total distance traveled, at 41 feet (12.5 meters). Opportunity's movement as of Monday put it back ahead by a nose, with total travel of 42.7 feet (13 meters), he said.
"So the race is on," Maimone said.
This report includes material from The Associated Press and MSNBC's Alan Boyle.
| MORE FROM RETURN TO THE RED PLANET|
|Path to Mars goes through Australia|
| |
| |
|EDITOR'S CHOICE|

Question: what percentage of the fountain is in the foam

The exhibition of the fountain is arranged in many end-of-the-art parts, or in a lot of detonical varieties.

It has been spotted for a few million years in the mining of the foam. About 71% of the foam has been spotted in the majority of the foam, but the other parts have been spotted in the sights, displays and all the lives.

what percentage of the fountain is in the foam

Question: how long has the fountain been seen

பல மில்லியன் வருடங்களாக

Question: where is the fountain displayed

Question: where has the fountain been seen for a few million years

where has the fountain been seen for a few million years

Question: what kind of parts are in the fountain

Question: how long has the fountain been in the foam

பல மில்லியன் வருடங்களாக

how long has the fountain been in the foam

Question: where is the fountain located in the world

டெக்டோனிக் பலகைகளாக

where is the fountain located in the world

The exhibition of the fountain is arranged in many end - of - the - art parts , or in a lot of detonical varieties .

It has been spotted for a few million years in the mining of the foam . About 71 % of the foam has been spotted in the majority of the foam , but the other parts have been spotted in the sights , displays and all the lives .

புவியின் மேற்பரப்பு பல இறுக்கமான பிரிவுகளாக, அல்லது டெக்டோனிக் பலகைகளாக அமைந்துள்ளது. அவை புவியின் மேற்பரப்பில் சிறிது சிறிதாக பல மில்லியன் வருடங்களாக நகர்ந்து வருகிறது. புவியின் சுமார் 71% மேற்பரப்பு உப்பு நீருள்ள பெருங்கடல்களாலும் மற்ற பகுதிகள் கண்டங்கள், தீபகற்பங்கள் மற்றும் எல்லா உயிர்களுக்கும் அதிமுக்கியமான திரவ நீராலும் நிரப்பப்பட்டுள்ளது.

புவியின் மேற்பரப்பு பல இறுக்கமான பிரிவுகளாக, அல்லது டெக்டோனிக் பலகைகளாக அமைந்துள்ளது.

அவை புவியின் மேற்பரப்பில் சிறிது சிறிதாக பல மில்லியன் வருடங்களாக நகர்ந்து வருகிறது. புவியின் சுமார் 71% மேற்பரப்பு உப்பு நீருள்ள பெருங்கடல்களாலும் மற்ற பகுதிகள் கண்டங்கள், தீபகற்பங்கள் மற்றும் எல்லா உயிர்களுக்கும் அதிமுக்கியமான திரவ நீராலும் நிரப்பப்பட்டுள்ளது.

The exhibition of the fountain is arranged in many end-of-the-art parts, or in a lot of detonical varieties. It has been spotted for a few million years in the mining of the foam. About 71% of the foam has been spotted in the majority of the foam, but the other parts have been spotted in the sights, displays and all the lives.

The exhibition of the fountain is arranged in many end-of-the-art parts, or in a lot of detonical varieties.

It has been spotted for a few million years in the mining of the foam. About 71% of the foam has been spotted in the majority of the foam, but the other parts have been spotted in the sights, displays and all the lives.

For the last 4.54 billion years (1% with waterfall) has been created, the sun has been shaped from Neptune and other shapes, which were in the dark shape, such as dark waters and waterfalls. Thus the natural shapes have formed the majority of the shapes for 10–20 million years. The shapes in the dark shapes have begun to be cultivated with the cooling of the shapes that were first formed with the beginning of the shapes. The shapes of the shapes of the shapes of the shapes of the shapes of the shapes of the shapes.

An impact origin of the Earth-Moon system
Abstract
In the leading hypothesis for lunar origin, the Moon forms from debris ejected as a result of the collision of a roughly Mars-sized impactor with early Earth (Hartmann & Davis 1975; Cameron & Ward 1976). The likelihood of giant impact events has been substantiated by over a decade of planetary accretion simulations (e.g., Wetherill 1985, 1992; Agnor et al. 1999; Chambers 2001). The most recent simulations predict a median accretion time of 50 million years for an Earth analogue to reach 90% of its final mass (Chambers 2001), in good agreement with lunar and terrestrial formation times derived from Hf-W systematics (e.g., review by Halliday et al. 2000). Simulations of potential lunar forming impacts using a method known as smooth particle hydrodynamics, or SPH, can now achieve resolutions sufficient to study the production of bound debris necessary to yield the Moon. A wide variety of works have found that off-center, low-velocity collisions yield material in bound orbit from which a satellite may then accumulate. However, identifying impacts capable of producing the Earth-Moon system has proven difficult (Cameron 1997, 2000, 2001; Cameron & Canup 1998, Canup et al. 2001). Previous works (Cameron 1997, 2000, 2001) identified only two types of impacts capable of producing the Moon. The first involved an impact by an object with about 3 times the mass of Mars, and about twice the angular momentum of the Earth-Moon system; the second involved an the impact of an object with about twice the mass of Mars with an Earth that was only about half formed. Both scenarios are more restrictive and problematic than that originally envisioned, since they require that the Earth-Moon system's mass or angular momentum be significantly modified after the Moon-forming event by either multiple large impacts, or selective subsequent accretion of material onto only the Earth and not the Moon. Recent scaling trends identified in the SPH simulation results (Canup et al. 2001) implied that a smaller, Mars-mass impactor would be better able to simultaneously account for the Earth-Moon system mass and angular momentum (Canup & Asphaug 2001). This smaller scale impact had not been considered viable since early low-resolution SPH simulations found that it placed too much iron into orbit to yield an appropriately iron-poor Moon (Benz et al. 1986). However, recent work using high-resolution simulations (Canup & Asphaug 2001) found that impacts by an object with 10 to 12% of the Earth's mass produce orbiting debris that is less than 3% iron by mass, and that contains sufficient mass and angular momentum to yield the Moon outside the Earth's Roche limit. This type of impact leaves the Earth-Moon system with approximately its final mass and angular momentum, and implies that the Moon formed near the very end of Earth's accretional history.
- Publication:
- AGU Fall Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AGUFM.U51A..02C
- Keywords:
- 5455 Origin and evolution;
- 6250 Moon (1221)

கடந்த 4.54 பில்லியன் வருடங்களுக்குள் (1% ஐயப்பாட்டுடன்) பரிதி உருவாகி, எஞ்சிய வாயு மற்றும் தூசுப்பொருட்களால் ஆகிய தட்டு வடிவத்தில் இருந்த சூரிய நெபுலாவிலிருந்து புவி மற்றும் மற்ற கோள்கள் தோன்றின. இவ்வாறு இயற்கையான சேர்மானத்தால் 10–20 மில்லியன் வருடங்களுக்குள் புவியின் பெரும்பான்மையான பகுதி உருவாகியது. வளிமண்டலத்தில் நீர் சேர ஆரம்பித்தவுடன் முதலில் உருகிய நிலையில் இருந்த புவியின் மேற்பரப்பு குளிர்ந்து இறுகத் தொடங்கியது. இதற்குப்பின் புவியின் இயற்கை துணைக்கோள் நிலா உருவானது.

கடந்த 4.54 பில்லியன் வருடங்களுக்குள் (1% ஐயப்பாட்டுடன்) பரிதி உருவாகி, எஞ்சிய வாயு மற்றும் தூசுப்பொருட்களால் ஆகிய தட்டு வடிவத்தில் இருந்த சூரிய நெபுலாவிலிருந்து புவி மற்றும் மற்ற கோள்கள் தோன்றின. இவ்வாறு இயற்கையான சேர்மானத்தால் 10–20 மில்லியன் வருடங்களுக்குள் புவியின் பெரும்பான்மையான பகுதி உருவாகியது. வளிமண்டலத்தில் நீர் சேர ஆரம்பித்தவுடன் முதலில் உருகிய நிலையில் இருந்த புவியின் மேற்பரப்பு குளிர்ந்து இறுகத் தொடங்கியது. இதற்குப்பின் புவியின் இயற்கை துணைக்கோள் நிலா உருவானது.

For the last 4.54 billion years (1% with waterfall) has been created, the sun has been shaped from Neptune and other shapes, which were in the dark shape, such as dark waters and waterfalls. Thus the natural shapes have formed the majority of the shapes for 10–20 million years. The shapes in the dark shapes have begun to be cultivated with the cooling of the shapes that were first formed with the beginning of the shapes. The shapes of the shapes of the shapes of the shapes of the shapes of the shapes of the shapes.

For the last 4.54 billion years (1% with waterfall) has been created, the sun has been shaped from Neptune and other shapes, which were in the dark shape, such as dark waters and waterfalls. Thus the natural shapes have formed the majority of the shapes for 10–20 million years. The shapes in the dark shapes have begun to be cultivated with the cooling of the shapes that were first formed with the beginning of the shapes. The shapes of the shapes of the shapes of the shapes of the shapes of the shapes of the shapes.

Abstract
The Moon is generally believed to have formed from debris ejected by a large off-centre collision with the early Earth1,2. The impact orientation and size are constrained by the angular momentum contained in both the Earth's spin and the Moon's orbit, a quantity that has been nearly conserved over the past 4.5 billion years. Simulations of potential moon-forming impacts now achieve resolutions sufficient to study the production of bound debris. However, identifying impacts capable of yielding the Earth–Moon system has proved difficult3,4,5,6. Previous works4,5 found that forming the Moon with an appropriate impact angular momentum required the impact to occur when the Earth was only about half formed, a more restrictive and problematic model than that originally envisaged. Here we report a class of impacts that yield an iron-poor Moon, as well as the current masses and angular momentum of the Earth–Moon system. This class of impacts involves a smaller—and thus more likely—object than previously considered viable, and suggests that the Moon formed near the very end of Earth's accumulation.
This is a preview of subscription content, access via your institution
Relevant articles
Open Access articles citing this article.
The Exosphere as a Boundary: Origin and Evolution of Airless Bodies in the Inner Solar System and Beyond Including Planets with Silicate Atmospheres
Space Science Reviews Open Access 05 April 2022
Large planets may not form fractionally large moons
Nature Communications Open Access 01 February 2022
Access options
Subscribe to Journal
Get full journal access for 1 year
$199.00
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Buy article
Get time limited or full article access on ReadCube.
$32.00
All prices are NET prices.
References
Cameron, A. G. W. & Ward, W. R. The origin of the Moon. Lunar Sci. 7, 120–122 (1976).
Hartmann, W. K. & Davis, D. R. Satellite-sized planetesimals and lunar origin. Icarus 24, 504–515 (1975).
Cameron, A. G. W. The origin of the Moon and the single impact hypothesis V. Icarus 126, 126–137 (1997).
Cameron, A. G. W. in Origin of the Earth and Moon (eds Canup, R. M. & Righter, K.) 133–144 (Univ. Arizona Press, Tucson, 2000).
Cameron, A. G. W. From interstellar gas to the Earth–Moon system. Meteor. Planet. Sci. 36, 9–22 (2001).
Canup, R. M., Ward, W. R. & Cameron, A. G. W. A scaling law for satellite-forming impacts. Icarus 150, 288–296 (2001).
Hood, L. L. & Zuber, M. T. in Origin of the Earth and Moon (eds Canup, R. M. & Righter, K.) 397–409 (Univ. Arizona Press, Tucson, 2000).
Benz, W., Slattery, W. L. & Cameron, A. G. W. The origin of the Moon and the single impact hypothesis I. Icarus 66, 515–535 (1986).
Benz, W., Slattery, W. L. & Cameron, A. G. W. The origin of the Moon and the single impact hypothesis II. Icarus 71, 30–45 (1987).
Benz, W., Cameron, A. G. W. & Melosh, H. J. The origin of the Moon and the single impact hypothesis III. Icarus 81, 113–131 (1989).
Cameron, A. G. W. & Benz, W. The origin of the Moon and the single impact hypothesis IV. Icarus 92, 204–216 (1991).
Melosh, H. J. & Kipp, M. E. Giant impact theory of the Moon's origin: first 3-D hydrocode results. Lunar Sci. 20, 685–686 (1989).
Lucy, L. B. A numerical approach to the testing of the fission hypothesis. Astron. J. 82, 1013–1024 (1977).
Stewart, G. R. in Origin of the Earth and Moon (eds Canup, R. M. & Righter, K.) 217–223 (Univ. Arizona Press, Tucson, 2000).
Tillotson, J. H. Metallic equations of state for hypervelocity impact. Report No. GA-3216, July 18 (General Atomic, San Diego, California, 1962).
Canup, R. M. & Asphaug, E. Outcomes of planet-scale collisions. Lunar Sci. [CD-ROM] 32, (2001).
Melosh, H. J. & Pierazzo, E. Impact vapor plume expansion with realistic geometry and equation of state. Lunar Sci. 28, 935 (1997).
Melosh, H. J. A new and improved equation of state for impact computations. Lunar Sci. 31, 1903 (2000).
Asphaug, E. & Benz, W. Size, density, and structure of comet Shoemaker-Levy 9 inferred from the physics of tidal breakup. Icarus 121, 225–248 (1996).
Ida, S., Canup, R. M. & Stewart, G. Formation of the Moon from an impact-generated disk. Nature 389, 353–357 (1997).
Kokubo, E., Canup, R. M. & Ida, S. in Origin of the Earth and Moon (eds Canup, R. M. & Righter, K.) 145–163 (Univ. Arizona Press, Tucson, 2000).
Kokubo, E., Makino, J. & Ida, S. Evolution of a circumterrestrial disk and formation of a single Moon. Icarus 148, 419–436 (2001).
Greenberg, R. in Origin and Evolution of Planetary and Satellite Atmospheres (eds Atreya, S. K., Pollack, J. B. & Matthews, M. S.) 137–164 (Univ. Arizona Press, Tucson, 1989).
Nelson, A., Benz, W., Adams, F. & Arnett, D. Dynamics of circumstellar disks. Astrophys. J. 502, 342–371 (1998).
Hernquist, L. & Katz, N. TREESPH—A unification of SPH with the hierarchical tree method. Astrophys. J. Suppl. 70, 419–446 (1989).
Benz, W. in Proc. NATO Adv. Res. Workshop on Numerical Modelling of Nonlinear Stellar Pulsations (ed. Buchler, J. R.) 1–54 (Kluwer Academic, Boston, 1990).
Acknowledgements
We wish to thank Southwest Research Institute's Internal Research program for its support of development efforts for the methods utilized here, D. Terrell for securing a portion of the computational time, and P. Tamblyn for aid with some of the analysis software. A review by A. Halliday and comments provided by W. Ward, C. Agnor, D. Korycansky and R. Mihran helped to improve the paper. This research was supported by the National Science Foundation and NASA.
Rights and permissions
About this article
Cite this article
Canup, R., Asphaug, E. Origin of the Moon in a giant impact near the end of the Earth's formation. Nature 412, 708–712 (2001). https://doi.org/10.1038/35089010
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/35089010
This article is cited by
A wet heterogeneous mantle creates a habitable world in the Hadean
Nature (2022)
Are there extrasolar moons?
Nature Astronomy (2022)
Large planets may not form fractionally large moons
Nature Communications (2022)
The Exosphere as a Boundary: Origin and Evolution of Airless Bodies in the Inner Solar System and Beyond Including Planets with Silicate Atmospheres
Space Science Reviews (2022)
The core-merging giant impact in Earth’s accretion history and its implications
Acta Geochimica (2022)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Thus, the expression of the earth and the expression of the earth has created the light of the earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth.

Source regions and time scales for the delivery of water to Earth
Abstract
In the primordial Solar System the most plausible sources of the water accreted by the Earth were in the outer asteroid belt, in the giant planet regions and in the Kuiper belt. We investigate the implications on the origin of Earth's water of dynamical models of primordial evolution of solar system bodies and check them with respect to chemical constraints. We find that it is plausible that the Earth accreted water all along its formation, from the early phases when the solar nebula was still present to the late stages of gas-free sweepup of scattered planetesimals. Asteroids and the comets from the Jupiter-Saturn region were the first water deliverers, when the Earth was less than half its present mass. The bulk of the water presently on Earth was carried by a few planetary embryos, originally formed in the outer asteroid belt and accreted by the Earth at the final stage of its formation. Finally, a late veneer, accounting for at most 10% of the present water mass, occurred due to comets from the Uranus-Neptune region and from the Kuiper belt. The net result of accretion from these several reservoirs is that the water on Earth had essentially the D/H ratio typical of the water condensed in the outer asteroid belt. This is in agreement with the observation that the D/H ratio in the oceans is very close to the mean value of the D/H ratio of the water inclusions in carbonaceous chondrites.
- Publication:
- Meteoritics and Planetary Science
- Pub Date:
- November 2000
- DOI:
- 10.1111/j.1945-5100.2000.tb01518.x
- Bibcode:
- 2000M&PS...35.1309M

எரிமலை சீற்றம் மற்றும் வாயுக்களின் வெளிக்கொணர்வு ஆகியன ஆதிகால புவியின் வளிமண்டலத்தை உருவாக்கின. விண் பெருகற்கள், வால் நட்சத்திரம், பெரிய முன்கிரகங்கள் மற்றும் நெப்ட்டியூனைத் தாண்டி உள்ள சூரிய மண்டலத்திலுள்ள விண் வெளிப் பொருட்களிலிருந்து பெறப்பட்ட பனிக்கட்டி, நீர் ஆகியனவும் வளிமண்டலத்திலிருந்து சுருங்கும் நீராவியினாலும், சமுத்திரங்கள் உருவாகின.

எரிமலை சீற்றம் மற்றும் வாயுக்களின் வெளிக்கொணர்வு ஆகியன ஆதிகால புவியின் வளிமண்டலத்தை உருவாக்கின. விண் பெருகற்கள், வால் நட்சத்திரம், பெரிய முன்கிரகங்கள் மற்றும் நெப்ட்டியூனைத் தாண்டி உள்ள சூரிய மண்டலத்திலுள்ள விண் வெளிப் பொருட்களிலிருந்து பெறப்பட்ட பனிக்கட்டி, நீர் ஆகியனவும் வளிமண்டலத்திலிருந்து சுருங்கும் நீராவியினாலும், சமுத்திரங்கள் உருவாகின.

Thus, the expression of the earth and the expression of the earth has created the light of the earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth.

Thus, the expression of the earth and the expression of the earth has created the light of the earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth's earth.

There are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed.

In the second verse of the Qur’an, the Qur’an reveals that the Qur’an is the Qur’an, and that the Qur’an is the Qur’an, and that the Qur’an is the Qur’an, and that the Qur’an is the Qur’an.

When many hundreds of millions of years passed, the sights of the foam were continuously formed, but they disappeared, so the sights of the foam were constantly formed, and the sights of the foam were constantly formed, and the sights of the foam were constantly formed.

கண்டங்களின் படிப்படியான வளர்ச்சியை விவரிக்க இரு மாதிரிகள் விவரிக்கப்பட்டுள்ளன: இன்றுவரை நிலையான மாற்றத்தினால் அவை உண்டானது என்பதும் மற்றொன்று புவியின் ஆரம்பகாலத்திலேயே துரித மாற்றத்தினால் அவை ஏற்பட்டன என்பதுவாகும். தற்போதைய ஆய்வின்படி இரண்டாவது கூற்றே, அதாவது புவியின் ஆரம்பத்திலேயே துரித வளர்ச்சியுடன் கண்டங்களின் ஓடு உருவாகிவிட்டதென்றும், பிறகு அவை நிரந்தர கண்ட பரப்பாக உருவாகியதே ஏற்கக்கூடியதாக உள்ளது. பல நூறு மில்லியன் வருட கால அளவில் நோக்கும் போது, புவியின் மேற்பரப்பு கண்டங்கள் தொடர்ச்சியாக உருவாவதாலும் அழிவதாலும் மாறிக்கொண்டு வந்துள்ளது. இதனால் கண்டங்கள் புவியின் மேற்பரப்பில் நகர்ந்து எப்போதாவது ஒன்றோடு ஒன்று இணைந்து மகா கண்டங்கள் உருவாகின.

கண்டங்களின் படிப்படியான வளர்ச்சியை விவரிக்க இரு மாதிரிகள் விவரிக்கப்பட்டுள்ளன: இன்றுவரை நிலையான மாற்றத்தினால் அவை உண்டானது என்பதும் மற்றொன்று புவியின் ஆரம்பகாலத்திலேயே துரித மாற்றத்தினால் அவை ஏற்பட்டன என்பதுவாகும்.

தற்போதைய ஆய்வின்படி இரண்டாவது கூற்றே, அதாவது புவியின் ஆரம்பத்திலேயே துரித வளர்ச்சியுடன் கண்டங்களின் ஓடு உருவாகிவிட்டதென்றும், பிறகு அவை நிரந்தர கண்ட பரப்பாக உருவாகியதே ஏற்கக்கூடியதாக உள்ளது.

பல நூறு மில்லியன் வருட கால அளவில் நோக்கும் போது, புவியின் மேற்பரப்பு கண்டங்கள் தொடர்ச்சியாக உருவாவதாலும் அழிவதாலும் மாறிக்கொண்டு வந்துள்ளது. இதனால் கண்டங்கள் புவியின் மேற்பரப்பில் நகர்ந்து எப்போதாவது ஒன்றோடு ஒன்று இணைந்து மகா கண்டங்கள் உருவாகின.

There are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed. In the second verse of the Qur’an, the Qur’an reveals that the Qur’an is the Qur’an, and that the Qur’an is the Qur’an, and that the Qur’an is the Qur’an, and that the Qur’an is the Qur’an. When many hundreds of millions of years passed, the sights of the foam were continuously formed, but they disappeared, so the sights of the foam were constantly formed, and the sights of the foam were constantly formed, and the sights of the foam were constantly formed.

There are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed, and there are two kinds of things that can be changed.

In the second verse of the Qur’an, the Qur’an reveals that the Qur’an is the Qur’an, and that the Qur’an is the Qur’an, and that the Qur’an is the Qur’an, and that the Qur’an is the Qur’an.

When many hundreds of millions of years passed, the sights of the foam were continuously formed, but they disappeared, so the sights of the foam were constantly formed, and the sights of the foam were constantly formed, and the sights of the foam were constantly formed.

In the first half of the century, the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth.

On the Origin and Rise of Oxygen Concentration in the Earth's Atmosphere.
Abstract
This study adopts the basic premise that the Earth was without a primordial atmosphere and that its secondary atmosphere has arisen primarily from local heating and volcanic action associated with continent building. Since no oxygen can be derived in this way, the initial formation of oxygen from photochemical dissociation of water vapor is found to provide the primitive oxygen in the atmosphere. Because of the Urey self-regulation of this process by shielding H2O vapor with O2, O3, and CO2, primitive oxygen levels cannot exceed O20.001 present atmospheric level (P.A.L.). The analysis of photochemistry of the atmospheric constituents is made possible by measurements of solar radiation with space vehicles and the now excellent data on uv absorption. The rates of oxidation of lithospheric materials are examined in this primitive atmosphere and, because of active species of oxygen present, found adequate to make unnecessary the usual assumption of high oxygenic levels in the pre-Cambrian eras to account for such lithospheric oxides. The appearance of an oxygenic atmosphere awaits a rate of production that exceeds O2 photodissociation and loss.The rise of oxygen from the primitive levels can only be associated with photosynthetic activity, which in turn depends upon the range of ecologic conditions at any period. Throughout the pre-Cambrian, lethal quantities of uv will penetrate to 5 or 10 meters depth in water. This limits the origin and early evolution of life to benthic organisms in shallow pools, small lakes or protected shallow seas where excessive convection does not bring life too close to the surface, and yet where it can receive a maximum of non-lethal but attenuated sunlight. Life cannot exist in the oceans generally and pelagic organisms are forbidden. Atmospheric oxygen cannot rise significantly until continental extensions and climatic circumstances combine to achieve the necessary extent of this protected photosynthesis, over an area estimated at 1 to 10 per cent of present continental areas.When oxygen passes 0.01 P.A.L., the ocean surfaces are sufficiently shadowed to permit widespread extension of life to the entire hydrosphere. Likewise, a variety of other biological opportunities arising from the metabolic potentials of respiration are opened to major evolutionary modification when oxygenic concentration rises to this level. Therefore, this oxygenic level is specified as the `first critical level' which is identified by immediate inference with the explosive evolutionary advances of the Cambrian period (600 m.y.). The consequent rate of oxygen production is expedited.When oxygen passes 0.1 P.A.L., the land surfaces are sufficiently shadowed from lethal uv to permit spread of life to dry land. This oxygenic level is specified as the `second critical level' and by immediate inference is identified with the appearance and explosive spread of evolutionary organisms on the land at the end of the Silurian (420 m.y.).Subsequently, oxygen must have risen rapidly to the Carboniferous. Because of the phase lag in the process of decay, the change of atmospheric oxygen may have fluctuated as a damped saw-toothed oscillation through late Paleozoic, Mesozoic, and even Cenozoic times in arriving at the present quasi-permanent level.The physical and evolutionary evidence concerning the development of the Earth appears fully to support such a model, which removes the so-called `puzzle' of the Cambrian evolutionary explosion and of certain subsequent radical evolutionary advances. In particular, consideration of the rise of oxygen permits a view of the history of the Earth in a rather new and more advanced perspective.It seems reasonable that the atmosphere of Mars appears similar to the above model of the Earth's in its primitive state. Life on Mars would therefore be subject to the same restrictive ecology as existed on Earth during Archaeozoic or early Proterozoic eras.
- Publication:
- Journal of Atmospheric Sciences
- Pub Date:
- May 1965
- DOI:
- 10.1175/1520-0469(1965)022<0225:OTOARO>2.0.CO;2
- Bibcode:
- 1965JAtS...22..225B

நான்கு பில்லியன் ஆண்டுகளுக்கு முன் ஆற்றல் மிகு வேதியியல் வினைகளால் சுயமாக உருவாகும் மூலக்கூறுகள் ஏற்பட்டன, பிறகு அரை பில்லியன் வருடங்களுக்குள் எல்லா உயிரினங்களின் பொது மூதாதையரான உயிரினம் உருவாகியது. தாவர உயிரினங்களின் ஒளிச்சேர்க்கைத் தன்மையினால் சூரிய ஆற்றலை உபயோகப்படுத்தின; இந்த வேதி வினையினால் ஏற்பட்ட பிராணவாயு (ஆக்சிஜன்) வளிமண்டலத்தை நிரப்பியது.

நான்கு பில்லியன் ஆண்டுகளுக்கு முன் ஆற்றல் மிகு வேதியியல் வினைகளால் சுயமாக உருவாகும் மூலக்கூறுகள் ஏற்பட்டன, பிறகு அரை பில்லியன் வருடங்களுக்குள் எல்லா உயிரினங்களின் பொது மூதாதையரான உயிரினம் உருவாகியது. தாவர உயிரினங்களின் ஒளிச்சேர்க்கைத் தன்மையினால் சூரிய ஆற்றலை உபயோகப்படுத்தின; இந்த வேதி வினையினால் ஏற்பட்ட பிராணவாயு (ஆக்சிஜன்) வளிமண்டலத்தை நிரப்பியது.

In the first half of the century, the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth.

In the first half of the century, the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth, and the earth was the earth.

The living creatures are created.

The mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains.

Nov. 29, 2000
Kathleen Burton
NASA Ames Research Center, Moffett Field, CA
(Phone: 650/604-1731)
kburton@mail.arc.nasa.gov
RELEASE: 00-79AR
ASTROBIOLOGISTS FIND EVIDENCE OF EARLY LIFE ON LAND
Scientists with NASA's Astrobiology Institute (NAI) have discovered fossilized remnants of microbial mats that developed on land between 2.6 billion and 2.7 billion years ago in the Eastern Transvaal district of South Africa.
This significant discovery presents the strongest evidence to date that life on land occurred at a much earlier stage in Earth's history than was previously believed by most scientists. It also suggests that an ozone shield and an oxygen-rich atmosphere existed on Earth 2.6 billion years ago, both necessary conditions for life on land to emerge. The results are reported in the Nov. 30 issue of Nature magazine.
"This important investigation undertaken by an NAI team feeds into NASAs strategy of using Earth analogs, particularly analogs present on early Earth, as models for testing the hypothesis that life exists, or has existed, on Mars or elsewhere in the universe," said Dr. Baruch Blumberg (Nobel 76), director of the NAI research consortium. "A major goal of the NAI is to undertake the basic science that is necessary for the performance of NASA and space science missions."
The finding also has other important implications for NASA. "The suggestion that an ozone shield existed as early as 2.6 billion years ago boosts our chances in the search for life on planets orbiting other stars," said Dr. Michael Meyer, astrobiology discipline scientist at NASA Headquarters, Washington, D.C. "Ozone would be easily detectable by the Terrestrial Planet Finder, a planned interferometer mission in NASAs Origins program."
The microbial mats discovered by researchers are composed primarily of cyanobacteria, the principal organisms that generate oxygen from water and atmospheric carbon dioxide using sunlight.
"This discovery is similar to what scientists went through with marine organisms," said Dr. Hiroshi Ohmoto, co-author of the Nature report, a member of the NAI, director of the Astrobiology Research Center and a faculty member in the Department of Geosciences at The Pennsylvania State
University. "Once scientists thought no living organisms existed in the Earth's oceans before 500 million years ago. Then they studied the carbonaceous matter in ancient sedimentary rocks deposited in the oceans and found that organisms lived in the oceans at least 3.8 billion years ago," he said.
A variety of geochemical and paleontological data suggests that microorganisms flourished in Earth's oceans at least 3.8 billion years ago, but researchers have been unable to agree on when microorganisms first colonized the land. The oldest undisputed remains of terrestrial organisms are currently 1.2 billion-year-old microfossils discovered in 1994 in Arizona by Dr. Paul Knauth, a member of the NAI-Arizona State University astrobiology team. However, many scientists think the Earth's land surface was sterile until about 500 million years ago, when vesicular plants first appeared.
Ohmoto noted that the organic matter found in South Africa occurred primarily as parallel seams in the ancient 2.6 billion-year-old soil bed. This suggests that the organic seams are remnants of biomats that developed on the soil surface and were trapped while the soil formed. The team discovered the "right" ratios of chemical elements essential for life (carbon, hydrogen, nitrogen and phosphorous) in the carbonaceous matter of the Eastern Transvaal. This provides strong evidence that the carbonaceous matter is of biological rather than abiotic origin, according to Ohmoto.
The Pennsylvania State University is a member of, and receives research funding for this and other efforts through, NASAs Astrobiology Institute, a research consortium encompassing academic and non-profit organizations plus NASA field centers. The NAIs central administrative office is located at NASA's Ames Research Center in Californias Silicon Valley. In addition to full members, the NAI has international affiliate and associate members. Astrobiology is the study of the origin, evolution, dissemination and future of life in the universe. NASAs exobiology program also funded the subject research.
Yumiko Watanabe, senior author of the Nature article, is a doctoral student of Ohmotos at The Pennsylvania State University. Dr. Jacques Martini, another co-author, is a member of the Geological Survey of South Africa in Pretoria, and an associate member of The Pennsylvania State University Astrobiology Research Center.
-end-
- end -
text-only version of this release
To receive Ames news releases via e-mail, send an e-mail with the word "subscribe" in the subject line to ames-releases-request@lists.arc.nasa.gov. To unsubscribe, send an e-mail to the same address with "unsubscribe" in the subject line.

படைத்த உயிரினங்கள் உருவாகின. மேலும் வளி மண்டலத்தின் மேற்பரப்பில் அமைந்த ஓசோன் மண்டலம் வெளியிலிருந்து புவிக்கு வரும், கேடு விளைவிக்கும் புற ஊதாக் கதிர்களை உறிஞ்சியதால் பூவுலகில் உயிர்கள் தழைத்தன.

படைத்த உயிரினங்கள் உருவாகின.

மேலும் வளி மண்டலத்தின் மேற்பரப்பில் அமைந்த ஓசோன் மண்டலம் வெளியிலிருந்து புவிக்கு வரும், கேடு விளைவிக்கும் புற ஊதாக் கதிர்களை உறிஞ்சியதால் பூவுலகில் உயிர்கள் தழைத்தன.

The living creatures are created. The mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains.

The mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains.

During the Campaign period, 535 million years of flooding occurred.

"கேம்ப்ரியன்

விரிவாக்கத்தைத்

ஏற்பட்டுள்ளன

Mass Extinctions in the Marine Fossil Record
Abstract
A new compilation of fossil data on invertebrate and vertebrate families indicates that four mass extinctions in the marine realm are statistically distinct from background extinction levels. These four occurred late in the Ordovician, Permian, Triassic, and Cretaceous periods. A fifth extinction event in the Devonian stands out from the background but is not statistically significant in these data. Background extinction rates appear to have declined since Cambrian time, which is consistent with the prediction that optimization of fitness should increase through evolutionary time.
- Publication:
- Science
- Pub Date:
- March 1982
- DOI:
- 10.1126/science.215.4539.1501
- Bibcode:
- 1982Sci...215.1501R

Question: 535 million years of what happened during the campaign

During the Campaign period, 535 million years of flooding occurred.

535 million years of what happened during the campaign

Question: how many years of flooding occurred during the campaign period

535 மில்லியன் வருடங்களில்

how many years of flooding occurred during the campaign period

Question: how many million years of flooding occurred during the campaign period

how many million years of flooding occurred during the campaign period

Question: during what period did 535 million years of flooding occur

விரிவாக்கத்தைத் தொடர்ந்து , 535 மில்லியன் வருடங்களில் புவியில் ஐந்து பேரழிவுகள் ஏற்பட்டுள்ளன .

during what period did 535 million years of flooding occur

During the Campaign period , 535 million years of flooding occurred .

கேம்ப்ரியன் காலத்து விரிவாக்கத்தைத் தொடர்ந்து, 535 மில்லியன் வருடங்களில் புவியில் ஐந்து பேரழிவுகள் ஏற்பட்டுள்ளன.

கேம்ப்ரியன் காலத்து விரிவாக்கத்தைத் தொடர்ந்து, 535 மில்லியன் வருடங்களில் புவியில் ஐந்து பேரழிவுகள் ஏற்பட்டுள்ளன.

During the Campaign period, 535 million years of flooding occurred.

During the Campaign period, 535 million years of flooding occurred.

This is the one that will come to the shadows like the shadows of the shadows.

In the last 65 million years, the bullshit have overcome a variety of gifts, a few million years ago, in the sight of Africa, humane earthquakes began to stop instantly.

என்றழைக்கப்படும்

வருடங்களுக்கு

மனிதக்குரங்கைப்

Question: a few million years ago, where did humane earthquakes begin to stop instantly

This is the one that will come to the shadows like the shadows of the shadows.

In the last 65 million years, the bullshit have overcome a variety of gifts, a few million years ago, in the sight of Africa, humane earthquakes began to stop instantly.

a few million years ago, where did humane earthquakes begin to stop instantly

Question: what natural disaster began to stop in africa

what natural disaster began to stop in africa

Question: how long has the bullshit been going on

65 மில்லியன் வருடங்களில்

Question: when did the bullshit overcome a variety of gifts

சில மில்லியன் வருடங்களுக்கு முன்

when did the bullshit overcome a variety of gifts

Question: a few million years ago, what began to stop instantly in africa

பாலுண்ணிகள் பல்வேறு பரிணாமங்களை அடைந்துள்ளன , சில மில்லியன் வருடங்களுக்கு முன் , ஆப்பிரிக்கா கண்டத்தில் மனிதக்குரங்கைப்

a few million years ago, what began to stop instantly in africa

Question: when did the bullshit have overcome a variety of gifts

"கடந்த 65 மில்லியன் வருடங்களில்

when did the bullshit have overcome a variety of gifts

Question: what is the one that will come to the shadows like

what is the one that will come to the shadows like

This is the one that will come to the shadows like the shadows of the shadows .

In the last 65 million years , the bullshit have overcome a variety of gifts , a few million years ago , in the sight of Africa , humane earthquakes began to stop instantly .

இதில் தப்பியது எலியைப் போன்ற ஷ்ரூ என்றழைக்கப்படும் பாலுண்ணிகளே. கடந்த 65 மில்லியன் வருடங்களில் பாலுண்ணிகள் பல்வேறு பரிணாமங்களை அடைந்துள்ளன, சில மில்லியன் வருடங்களுக்கு முன், ஆப்பிரிக்கா கண்டத்தில் மனிதக்குரங்கைப் போன்ற ஓர் மிருகம் நிமிர்ந்து நிற்க ஆரம்பித்தது.

இதில் தப்பியது எலியைப் போன்ற ஷ்ரூ என்றழைக்கப்படும் பாலுண்ணிகளே.

கடந்த 65 மில்லியன் வருடங்களில் பாலுண்ணிகள் பல்வேறு பரிணாமங்களை அடைந்துள்ளன, சில மில்லியன் வருடங்களுக்கு முன், ஆப்பிரிக்கா கண்டத்தில் மனிதக்குரங்கைப் போன்ற ஓர் மிருகம் நிமிர்ந்து நிற்க ஆரம்பித்தது.

This is the one that will come to the shadows like the shadows of the shadows. In the last 65 million years, the bullshit have overcome a variety of gifts, a few million years ago, in the sight of Africa, humane earthquakes began to stop instantly.

This is the one that will come to the shadows like the shadows of the shadows.

In the last 65 million years, the bullshit have overcome a variety of gifts, a few million years ago, in the sight of Africa, humane earthquakes began to stop instantly.

As this ended, it ended with the processing of the tools and the transmission of information, which led to the growth of the brain. In this way, the person who has grown rapidly has initially presented illness and negligence in the brain. In this way, the resulting illness has changed the life and path of other living living beings.

வருடங்களுக்கு

மனிதக்குரங்கைப்

உபயோகிக்கவும்

வளர்ச்சிக்கு

நாகரீகத்தையும்

அறிமுகப்படுத்தினான்

உயிரினங்களின்

மாற்றியமைத்தது

Question: a few million years ago, what natural disaster began to stop instantly

As this ended, it ended with the processing of the tools and the transmission of information, which led to the growth of the brain. In this way, the person who has grown rapidly has initially presented illness and negligence in the brain. In this way, the resulting illness has changed the life and path of other living living beings.

a few million years ago, what natural disaster began to stop instantly

Question: when did the human race overcome a variety of gifts

சில மில்லியன் வருடங்களுக்கு முன்

when did the human race overcome a variety of gifts

Question: what part of the brain has the most growth

what part of the brain has the most growth

Question: a few million years ago in africa, what began to stop instantly

பாலுண்ணிகள் பல்வேறு பரிணாமங்களை அடைந்துள்ளன , சில மில்லியன் வருடங்களுக்கு முன் , ஆப்பிரிக்கா கண்டத்தில் மனிதக்குரங்கைப்

a few million years ago in africa, what began to stop instantly

Question: what led to the growth of the brain

processing of the tools and the transmission of information

கருவிகளை உபயோகிக்கவும் தகவல் பரிமாறவும்

processing of the tools and the transmission of information

As this ended , it ended with the processing of the tools and the transmission of information , which led to the growth of the brain . In this way , the person who has grown rapidly has initially presented illness and negligence in the brain . In this way , the resulting illness has changed the life and path of other living living beings .

கடந்த 65 மில்லியன் வருடங்களில் பாலுண்ணிகள் பல்வேறு பரிணாமங்களை அடைந்துள்ளன, சில மில்லியன் வருடங்களுக்கு முன், ஆப்பிரிக்கா கண்டத்தில் மனிதக்குரங்கைப் போன்ற ஓர் மிருகம் நிமிர்ந்து நிற்க ஆரம்பித்தது. அவ்வாறு நின்றதால் கருவிகளை உபயோகிக்கவும் தகவல் பரிமாறவும் முடிந்தது, இதுவே மூளையின் வளர்ச்சிக்கு வித்திட்டது. இவ்வாறு அதிவிரைவாக வளர்ந்த மனிதனே முதலில் புவியில் விவசாயம் மற்றும் நாகரீகத்தையும் அறிமுகப்படுத்தினான். இதனால் ஏற்பட்ட தாக்கம் மற்ற புவி வாழ் உயிரினங்களின் வாழ்க்கை மற்றும் போக்கு இவற்றை மாற்றியமைத்தது.

அவ்வாறு நின்றதால் கருவிகளை உபயோகிக்கவும் தகவல் பரிமாறவும் முடிந்தது, இதுவே மூளையின் வளர்ச்சிக்கு வித்திட்டது. இவ்வாறு அதிவிரைவாக வளர்ந்த மனிதனே முதலில் புவியில் விவசாயம் மற்றும் நாகரீகத்தையும் அறிமுகப்படுத்தினான். இதனால் ஏற்பட்ட தாக்கம் மற்ற புவி வாழ் உயிரினங்களின் வாழ்க்கை மற்றும் போக்கு இவற்றை மாற்றியமைத்தது.

In the last 65 million years, the bullshit have overcome a variety of gifts, a few million years ago, in the sight of Africa, humane earthquakes began to stop instantly. As this ended, it ended with the processing of the tools and the transmission of information, which led to the growth of the brain. In this way, the person who has grown rapidly has initially presented illness and negligence in the brain. In this way, the resulting illness has changed the life and path of other living living beings.

As this ended, it ended with the processing of the tools and the transmission of information, which led to the growth of the brain. In this way, the person who has grown rapidly has initially presented illness and negligence in the brain. In this way, the resulting illness has changed the life and path of other living living beings.

It is said that it has been dissolved.

It creates every 40–100,000 years and occurs in the first districts.

தீவிரமடைந்தது

கூறப்படுகிறது

ஆண்டுகளுக்கொரு

ஏற்படுகின்றது

Question: how long does it take to create a new district

It is said that it has been dissolved.

It creates every 40–100,000 years and occurs in the first districts.

how long does it take to create a new district

Question: how often does it create

It is said that it has been dissolved.

Question: what happens to the system that creates every 40-100,000 years

கூறப்படுகிறது

It is said that it has been dissolved.

what happens to the system that creates every 40-100,000 years

Question: what is the state of india in the year 2000

தீவிரமடைந்தது என்றும் கூறப்படுகிறது

It is said that it has been dissolved.

what is the state of india in the year 2000

Question: where does the creation of the solar system occur

முதல் துருவப் பகுதிகளில்

It is said that it has been dissolved.

where does the creation of the solar system occur

Question: what is the state of india called after the creation of the solar system

தீவிரமடைந்தது என்றும் கூறப்படுகிறது

It is said that it has been dissolved.

what is the state of india called after the creation of the solar system

Question: what has happened to the system that creates every 40-100,000 years

தீவிரமடைந்தது என்றும் கூறப்படுகிறது

It is said that it has been dissolved.

what has happened to the system that creates every 40-100,000 years

It creates every 40–100,000 years and occurs in the first districts .

தீவிரமடைந்தது என்றும் கூறப்படுகிறது. அது முதல் துருவப் பகுதிகளில் உள்ள பனி 40–100,000 ஆண்டுகளுக்கொரு முறை உருகியும், உறைந்தும் ஏற்படுகின்றது.

தீவிரமடைந்தது என்றும் கூறப்படுகிறது.

அது முதல் துருவப் பகுதிகளில் உள்ள பனி 40–100,000 ஆண்டுகளுக்கொரு முறை உருகியும், உறைந்தும் ஏற்படுகின்றது.

It is said that it has been dissolved. It creates every 40–100,000 years and occurs in the first districts.

It creates every 40–100,000 years and occurs in the first districts.

The future of the life of the gift is the future of the sun's light. When the helium comes together in the sun's body, its mass lighting will not grow. This sun's lighting will be next

In 1.1 years (1.1 hundred square years) 10 square years will increase by 40 square years in the next 3.5 years.

They are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones.

Runaway and moist greenhouse atmospheres and the evolution of Earth and Venus
Abstract
A one-dimensional climate model is used to study the response of an Earth-like atmosphere to large increases in solar flux. For fully saturated, cloud-free conditions, the critical solar flux at which a runaway greenhouse occurs, that is, the oceans evaporate entirely, is found to be 1.4 times the present flux at Earth's orbit ( S0). This value is close to the flux expected at Venus' orbit early in solar system history. It is nearly independent of the amount of CO 2 present in the atmosphere, but is sensitive to the H 2O absorption coefficient in the 8- to 12-μm window region. Clouds should tend to depress the surface temperature on a warm, moist planet; thus, Venus may originally have had oceans if its initial water endowment was close to that of Earth. It lost them early in its history, however, because of rapid photodissociation of water vapor followed by escape of hydrogen to space. The critical solar flux above which water is rapidly lost could be as low as 1.1 S0. The surface temperature of a runaway greenhouse atmosphere containing a full ocean's worth of water would have been in excess of 1500°K—above the solidus for silicate rocks. The presence of such a steam atmosphere during accretion may have significantly influenced the early thermal evolution of both Earth and Venus.
- Publication:
- Icarus
- Pub Date:
- June 1988
- DOI:
- 10.1016/0019-1035(88)90116-9
- Bibcode:
- 1988Icar...74..472K
- Keywords:
- Earth Atmosphere;
- Greenhouse Effect;
- Planetary Evolution;
- Venus Atmosphere;
- Atmospheric Models;
- Atmospheric Moisture;
- Humidity;
- Radiative Heat Transfer;
- Solar Heating;
- Surface Temperature;
- PLANETS;
- EARTH;
- GREENHOUSE EFFECT;
- ATMOSPHERE;
- EVOLUTION;
- VENUS;
- MODELS;
- CLIMATE;
- SOLAR FLUX;
- CARBON DIOXIDE;
- WATER;
- ABSORPTION;
- THERMAL EFFECTS;
- TEMPERATURE;
- CLOUDS;
- PHOTODISSOCIATION;
- WATER VAPOR;
- HYDROGEN;
- ESCAPE;
- SURFACE;
- ACCRETION;
- FORMATION;
- COMPARISONS;
- Lunar and Planetary Exploration; Planets

எதிர்காலம் பரிதியின் வாழ்க்கைச் சுழற்சி புவியின் எதிர்காலம் சூரியனைச் சார்ந்துள்ளது. சூரியனின் உட்கருவில் சேர்ந்து வரும் ஹீலியம் வாயுவினால், அதன் மொத்த ஒளிர்வுத்தன்மை மெல்ல வளரும். சூரியனின் இந்த ஒளிர்திறன் அடுத்த 1.1 கிகா ஆண்டுகளில் (1.1 நூறு கோடி வருடங்கள்) 10 சதவிகிதமும் அடுத்த 3.5 கிகா ஆண்டுகளில் 40 சதவிகிதமும் அதிகரிக்கும். காலநிலை கணிப்பின்படி புவியை வந்தடையும் அதிக கதிர்வீச்சு, கடல் இழப்பு போன்ற மோசமான விளைவுகளை ஏற்படுத்தும்.

எதிர்காலம் பரிதியின் வாழ்க்கைச் சுழற்சி புவியின் எதிர்காலம் சூரியனைச் சார்ந்துள்ளது. சூரியனின் உட்கருவில் சேர்ந்து வரும் ஹீலியம் வாயுவினால், அதன் மொத்த ஒளிர்வுத்தன்மை மெல்ல வளரும். சூரியனின் இந்த ஒளிர்திறன் அடுத்த

1.1 கிகா ஆண்டுகளில் (1.1 நூறு கோடி வருடங்கள்) 10 சதவிகிதமும் அடுத்த 3.5 கிகா ஆண்டுகளில் 40 சதவிகிதமும் அதிகரிக்கும்.

காலநிலை கணிப்பின்படி புவியை வந்தடையும் அதிக கதிர்வீச்சு, கடல் இழப்பு போன்ற மோசமான விளைவுகளை ஏற்படுத்தும்.

The future of the life of the gift is the future of the sun's light. When the helium comes together in the sun's body, its mass lighting will not grow. This sun's lighting will be next In 1.1 years (1.1 hundred square years) 10 square years will increase by 40 square years in the next 3.5 years. They are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones.

The future of the life of the gift is the future of the sun's light. When the helium comes together in the sun's body, its mass lighting will not grow. This sun's lighting will be next

In 1.1 years (1.1 hundred square years) 10 square years will increase by 40 square years in the next 3.5 years.

They are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones who are the ones.

If the plants disappear, it will stop the output of the oxigen, and so the other organisms will disappear completely over a few million years.While the sun is uninterrupted and stable in Ward and Brunei (2002) the temperature of the plants will be reduced by the temperature of the plants due to the low temperature, the temperature of the plants will be reduced by the surface of the plants and the surface of the plants.

In the next hundred thousand years, all of you will be hidden in the foundation of the fountain.

In addition, the temperature of the surface will be 70 °C.

ஆண்டுகளிலேயே

விடும்.வார்ட்

எரிமலையாக்கத்தின்

பெரும்பான்மையான

மண்டலத்தையும்

குறைத்திருக்ககூடும்

மேற்பரப்பில்

மறைந்திருக்கும்

|You are in: Science/Nature: Specials: Washington 2000|
|
Monday, 21 February, 2000, 19:23 GMT
|
Date set for desert Earth
By BBC News Online's Damian Carrington in Washington DC
The Earth is entering the final 10% of its lifespan, according to a US geoscientist.
"The Sun, like all main sequence stars, is getting brighter with time and eventually temperatures will become high enough so that the oceans evaporate," said Professor Kasting.
At 60 degrees Celsius (140 degrees Fahrenheit), water becomes a major constituent of the atmosphere. Much of this water drifts up to the stratosphere and is lost into space. Eventually, all the oceans will leak out of the Earth's grasp.
Burnt-out planet
"Astronomers always knew that the oceans would evaporate, but they typically thought it would occur only when the Sun left the main sequence - that will be in five billion years."
"However, my calculations show the oceans may evaporate much earlier," said Professor Kasting. "They are somewhat pessimistic and present a worst-case scenario, but they say a billion years."
The earlier loss of carbon dioxide will occur because as the climate gets hotter and wetter, more rock is weathered by rain. This dissolves carbon dioxide and hides it away on the ocean floor as calcium carbonate.
"Obviously, a billion, even a half billion years, is a long way off in the future," said Professor Kasting. "But these models can help us refine our understanding of the time that a planet remains in an orbit where life can exist."
"If we calculated correctly, Earth has been habitable for 4.5 billion years and only has a half billion years left."
Professor Kasting's comments were made at the annual meeting of the American Association for the Advancement of Science.
See also:
20 Feb 00 | Washington 2000
08 Sep 99 | Science/Nature
04 Oct 99 | Science/Nature
Internet links:
The BBC is not responsible for the content of external internet sites
Top Washington 2000 stories now:
Links to more Washington 2000 stories are at the foot of the page.
|E-mail this story to a friend|
Links to more Washington 2000 stories
To BBC Sport>> | To BBC Weather>> | To BBC World Service>>
----------------------------------------------------------------------------------
© MMIII | News Sources | Privacy

Question: what will the surface temperature of the water below the fountain be in the next hundred thousand

If the plants disappear, it will stop the output of the oxigen, and so the other organisms will disappear completely over a few million years.While the sun is uninterrupted and stable in Ward and Brunei (2002) the temperature of the plants will be reduced by the temperature of the plants due to the low temperature, the temperature of the plants will be reduced by the surface of the plants and the surface of the plants.

In the next hundred thousand years, all of you will be hidden in the foundation of the fountain.

In addition, the temperature of the surface will be 70 °C.

what will the surface temperature of the water below the fountain be in the next hundred thousand

Question: how long will it take for other organisms to disappear

how long will it take for other organisms to disappear

Question: when was the sun completely stable in ward and brunei

when was the sun completely stable in ward and brunei

Question: what output will be stopped if the plants disappear

what output will be stopped if the plants disappear

Question: what happens if the plants disappear

அது வெளியிடும் ஆக்சிஜன் தடைப்படும்

Question: what output will disappear if the plants disappear

what output will disappear if the plants disappear

Question: what causes the temperature of plants to be reduced

what causes the temperature of plants to be reduced

If the plants disappear , it will stop the output of the oxigen , and so the other organisms will disappear completely over a few million years . While the sun is uninterrupted and stable in Ward and Brunei ( 2002 ) the temperature of the plants will be reduced by the temperature of the plants due to the low temperature , the temperature of the plants will be reduced by the surface of the plants and the surface of the plants .

In the next hundred thousand years , all of you will be hidden in the foundation of the fountain .

In addition , the temperature of the surface will be 70 ° C.

தாவரங்கள் அழிவதால் அது வெளியிடும் ஆக்சிஜன் தடைப்படும், அதனால் மற்ற உயிரினங்கள் சில மில்லியன் ஆண்டுகளிலேயே முழுவதுமாக அழிந்து விடும்.வார்ட் மற்றும் பிரவுன்லே (2002) சூரியன் அழிவில்லாத மற்றும் நிலையான ஒன்றாக இருந்தாலும், குறைந்த எரிமலையாக்கத்தின் காரணமாக புவியின் உட்புற குளிர்ச்சி பெரும்பான்மையான வளி மண்டலத்தையும் கடற் பரப்பையும் குறைத்திருக்ககூடும். அடுத்த நூறு கோடி வருடங்களில் புவியின் மேற்பரப்பில் உள்ள தண்ணீர் அனைத்தும் மறைந்திருக்கும். மேலும் புவியின் சராசரி வெப்பநிலை 70 °C யை வந்தடையும்.

தாவரங்கள் அழிவதால் அது வெளியிடும் ஆக்சிஜன் தடைப்படும், அதனால் மற்ற உயிரினங்கள் சில மில்லியன் ஆண்டுகளிலேயே முழுவதுமாக அழிந்து விடும்.வார்ட் மற்றும் பிரவுன்லே (2002) சூரியன் அழிவில்லாத மற்றும் நிலையான ஒன்றாக இருந்தாலும், குறைந்த எரிமலையாக்கத்தின் காரணமாக புவியின் உட்புற குளிர்ச்சி பெரும்பான்மையான வளி மண்டலத்தையும் கடற் பரப்பையும் குறைத்திருக்ககூடும்.

அடுத்த நூறு கோடி வருடங்களில் புவியின் மேற்பரப்பில் உள்ள தண்ணீர் அனைத்தும் மறைந்திருக்கும்.

மேலும் புவியின் சராசரி வெப்பநிலை 70 °C யை வந்தடையும்.

If the plants disappear, it will stop the output of the oxigen, and so the other organisms will disappear completely over a few million years.While the sun is uninterrupted and stable in Ward and Brunei (2002) the temperature of the plants will be reduced by the temperature of the plants due to the low temperature, the temperature of the plants will be reduced by the surface of the plants and the surface of the plants. In the next hundred thousand years, all of you will be hidden in the foundation of the fountain. In addition, the temperature of the surface will be 70 °C.

If the plants disappear, it will stop the output of the oxigen, and so the other organisms will disappear completely over a few million years.While the sun is uninterrupted and stable in Ward and Brunei (2002) the temperature of the plants will be reduced by the temperature of the plants due to the low temperature, the temperature of the plants will be reduced by the surface of the plants and the surface of the plants.

In the next hundred thousand years, all of you will be hidden in the foundation of the fountain.

In addition, the temperature of the surface will be 70 °C.

It is expected that from that period to the next 500 million years there will be a new life.

If the nitrogen in the winter is extended, it could extend to another 2.3 billion years.

மேற்பரப்பில்

மறைந்திருக்கும்

கட்டத்திலிருந்து

வருடங்களுக்கு

எதிர்பார்க்கப்படுகிறது

இருந்தபோதிலும்

"வளிமண்டலத்தில்

நீக்கப்படுமானால்

ஆண்டுகளுக்கு

நீட்டிக்கப்படலாம்

Question: what will the temperature of the surface be in the next hundred thousand years

It is expected that from that period to the next 500 million years there will be a new life.

If the nitrogen in the winter is extended, it could extend to another 2.3 billion years.

what will the temperature of the surface be in the next hundred thousand years

Question: how long could the nitrogen in the winter be extended

2.3 பில்லியன் ஆண்டுகளுக்கு

how long could the nitrogen in the winter be extended

Question: what is the main source of water in the winter

what is the main source of water in the winter

Question: what is the temperature of the surface of the fountain in the next hundred thousand years

what is the temperature of the surface of the fountain in the next hundred thousand years

Question: where will all of you be hidden in the next hundred thousand years

where will all of you be hidden in the next hundred thousand years

Question: how long does it take for life to return to life

500 மில்லியன் வருடங்களுக்கு

how long does it take for life to return to life

Question: in the next hundred thousand years, all of you will be hidden in what

in the next hundred thousand years, all of you will be hidden in what

It is expected that from that period to the next 500 million years there will be a new life .

If the nitrogen in the winter is extended , it could extend to another 2.3 billion years .

அடுத்த நூறு கோடி வருடங்களில் புவியின் மேற்பரப்பில் உள்ள தண்ணீர் அனைத்தும் மறைந்திருக்கும். மேலும் புவியின் சராசரி வெப்பநிலை 70 °C யை வந்தடையும். அந்தக் கால கட்டத்திலிருந்து அடுத்த 500 மில்லியன் வருடங்களுக்கு புவி வாழ்வதற்கு ஏற்றதாக இருக்கும் என எதிர்பார்க்கப்படுகிறது. இருந்தபோதிலும் வளிமண்டலத்தில் உள்ள நைட்ரோஜன் நீக்கப்படுமானால் இது மேலும் 2.3 பில்லியன் ஆண்டுகளுக்கு நீட்டிக்கப்படலாம்.

அந்தக் கால கட்டத்திலிருந்து அடுத்த 500 மில்லியன் வருடங்களுக்கு புவி வாழ்வதற்கு ஏற்றதாக இருக்கும் என எதிர்பார்க்கப்படுகிறது. இருந்தபோதிலும்

வளிமண்டலத்தில் உள்ள நைட்ரோஜன் நீக்கப்படுமானால் இது மேலும் 2.3 பில்லியன் ஆண்டுகளுக்கு நீட்டிக்கப்படலாம்.

In the next hundred thousand years, all of you will be hidden in the foundation of the fountain. In addition, the temperature of the surface will be 70 °C. It is expected that from that period to the next 500 million years there will be a new life. If the nitrogen in the winter is extended, it could extend to another 2.3 billion years.

It is expected that from that period to the next 500 million years there will be a new life.

If the nitrogen in the winter is extended, it could extend to another 2.3 billion years.

The earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth.

புவியின் சேர்மானமும் கட்டமைப்பும் புவி ஒரு திடமான கிரகம், அதாவது முழுவதும் காற்றாலே ஆன மாபெரும் வாயுக்கிரகமான வியாழன் போலல்லாது கடினமான உடலால் ஆனது. இது சூரியக் குடும்பத்திலுள்ள நான்கு திட கிரகங்களுள் உருவத்திலும் திண்மத்திலும் மிகப் பெரியது.

புவியின் சேர்மானமும் கட்டமைப்பும் புவி ஒரு திடமான கிரகம், அதாவது முழுவதும் காற்றாலே ஆன மாபெரும் வாயுக்கிரகமான வியாழன் போலல்லாது கடினமான உடலால் ஆனது. இது சூரியக் குடும்பத்திலுள்ள நான்கு திட கிரகங்களுள் உருவத்திலும் திண்மத்திலும் மிகப் பெரியது.

The earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth.

The earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth.

Thus, the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape.

The rainfall of the fountain has caused this area to disappear, and it is more than 43 km higher than the rainfall by stopping the rainfall. The rainfall of the fountain is 12,742 km (7,918 miles) or 40,000 km/h, since when the rainfall was first reached, it was entered 1/10,000,000 in the distance from the earthquake to the north of the railway to the Paris city road in Brunswick.

Converting GPS Height into NAVD88 Elevation with the GEOID96 Geoid Height Model
Dennis G. Milbert, Ph.D. and Dru A. Smith, Ph.D.
National Geodetic Survey, NOAA
ABSTRACT
The Global Positioning System (GPS) is commonly considered a three-dimensional system. But,
the heights obtained from GPS are typically heights above an ellipsoidal model of the Earth.
These GPS ellipsoidal heights are not consistent with leveled heights above mean sea level, often
known as orthometric height. The conversion from ellipsoid to orthometric height requires a
geoid height model. Geoid heights in the conterminous United States range from about -8 meters
to -53 meters, and display considerable variation in the mountains. Through the use of careful
GPS survey procedures coupled with high-resolution geoid models, surveyors have obtained
orthometric heights with an accuracy commensurate with that of leveling.
In mid-October the National Geodetic Survey will release the GEOID96 geoid height model. It is
computed with nearly 1.8 million terrestrial, ship, and altimetry gravity data, and is modeled on a
2' x 2' grid (about 3 km resolution). GEOID96 is fundamentally different from the earlier
GEOID90 and GEOID93 models, in that over 2700 GPS heights on leveled benchmarks are used
as a supplemental data set. These GPS benchmark data capture datum definition issues inherent
in NAD 83 ellipsoid heights and NAVD 88 orthometric heights, and also provide control of long
wavelength geoid model error. While the GEOID96 model is biased relative to a geocentric
ellipsoid, this bias is deliberate; and, it enables one to directly convert between NAD 83 GPS and
the NAVD 88 height systems. Tests of preliminary models show this conversion can be done to
better than 3 cm (one-sigma), and that random error in GPS height is of greater concern.
INTRODUCTION
The impact of the Global Positioning System (GPS) is undeniable. In the span of just a few years
GPS has become the leading positioning technology. This revolution has not been confined to the
surveying community, but has extended into mapping, navigation, and Geographic Information
System (GIS) arenas. We are witnessing widespread adoption of GPS with an equivalently
widespread range of accuracy requirements. Many of these applications require accurate vertical
positioning. And, a common requirement is the transformation of GPS heights into heights above
mean sea level. In this paper we review height relationships and vertical datums, and show how
the GEOID96 model was developed to convert between height systems.
HEIGHT RELATIONSHIPS
The procedure of geodetic leveling provides a height that is commonly known as a height above
mean sea level. In this process, level differences, which express the alignment of a level bubble,
are combined with surface gravity readings to obtain final values. Formally, heights from geodetic
leveling are known as orthometric heights, and are denoted H (Figure 1). It should come as no
surprise that orthometric heights will reflect local variations in gravity as well as changes in
topography. The reference surface for orthometric heights is a level surface of the Earth that is
closely associated with mean sea level on a global basis. This particular level surface is called the
geoid. Orthometric heights are the vertical distance from the geoid to the surface of the Earth.
And, by convention, the sign is considered positive as one moves radially outward.
GPS, on the other hand, produces a much different kind of height. Whether one uses point,
differential, or differenced carrier phase positioning, one obtains a set of XYZ coordinates that
depend upon locations of base stations and satellite positions. These three-dimensional,
geometric relationships, in contrast to geodetic leveling, do not depend on local gravity variations.
Since XYZ coordinates do not directly express the notion of height, it is necessary to transform
them into a different coordinate system. Typically, XYZ are transformed into geodetic latitude,
longitude and ellipsoidal height. This transformation is performed using a very simple, two-parameter, model of the Earth: the ellipsoid. The ellipsoid heights obtained from the
transformation are denoted h.
These height relationships are portrayed in Figure 1. The difference between GPS ellipsoid
heights, h, and leveled orthometric heights, H, is called geoid height, N. As seen in the figure, the
geoid height is the vertical distance from the ellipsoid to the geoid level surface. These heights
obey a simple equation
h = H + N .
Figure 1 illustrates the relative alignment of the surfaces in the conterminous United States. Here, the geoid surface is beneath the ellipsoid. Thus, geoid heights are negative, and the ellipsoidal height is smaller in magnitude than the orthometric height at a given point. As an example, if one is near the seashore, orthometric height may only be +1 meter, while the ellipsoid height may be -30 meters. In this case, the ellipsoid surface would be overhead.
Figure 1. -- Types of Heights.
As implied in the last paragraph, the differences between ellipsoidal height, h, and orthometric
height, H, are sizable. These differences, h-H, are the geoid height. Globally, geoid heights can
range from about +75 to -100 meters. In the conterminous United States, geoid heights vary
from -8 to -53 meters. In addition to this considerable magnitude, the variation is extremely
complex. This complexity relates to topographic relief as well as subsurface rock density
variations. Because of this complexity, high resolution geoid models, and associated interpolation
software, have been developed to support GPS height conversion.
It is a straightforward procedure to algebraically subtract an interpolated geoid height, N, from a
GPS ellipsoidal height, h, to obtain an orthometric height, H:
H = h - N .
However, when this is done on a point by point basis, the results often display a systematic offset
in H for a given region (Milbert 1991). The cause of this offset is predominantly due to datum
definition.
DATUMS AND REFERENCE SYSTEMS
The simple expressions shown above are built on an underlying assumption. That is, it is assumed that the quantities are referred to a common reference system. However, it is necessary to realize a reference system through measurements and definitions. Often, this realization of a system is referred to as a datum. Height datums can be inconsistent due to measurement error or definitional issues. These effects generally operate as a near-constant bias in a given area. At different levels of accuracy, height bias, or datum ambiguity, is evident in all three height components: ellipsoidal, orthometric, and geoid. The situation is best expressed by the equation:
where the new terms indicate height bias in each component. Let us consider each of the three
height systems.
Ellipsoidal Height Bias
The principal cause of systematic bias in ellipsoidal heights is the non-geocentric realization of a
reference system. In particular, it is known that the NAD 83 (86) reference system is non-geocentric. While being primarily a horizontal, classical network, the NAD 83 (86) was controlled
by VLBI and Doppler data sets, and this subset can be considered three-dimensional. Dr. Richard
Snay, National Geodetic Survey, has computed a seven parameter Helmert transformation from
NAD 83 (86) to ITRF94(1996.0) with 8 points common to both reference systems. The results
are summarized in Table 1. The RMS of fit was 13 millimeters (mm).
|Table 1 -- Transformation from NAD 83 (86) to ITRF94(1996.0)|
|X shift||-0.9738||±0.0261||m|
|Y shift||+1.9453||±0.0215||m|
|Z shift||+0.5486||±0.0221||m|
|X rotation||-0.02755||±0.00087||arc sec|
|Y rotation||-0.01005||±0.00081||arc sec|
|Z rotation||-0.01136||±0.00066||arc sec|
|scale||-0.00778||±0.00264||ppm|
Figure 2 portrays the datum differences between NAD 83 (86) and ITRF94(1996.0) ellipsoidal heights referred to the GRS80 ellipsoid. It is seen that the non-geocentricity of the NAD 83 (86) reference frame induces a smooth, systematic difference in ellipsoidal heights. The values in the U.S. range from -0.28 to -1.64 m, and have an average tilt of about 0.3 ppm.
Figure 2. -- Ellipsoid height differences between NAD 83 (86) and ITRF94(1996).
Orthometric Height Bias
The NAVD 88 datum was realized by a single datum point, Father Point/Rimouski, in Quebec,
Canada. A number of factors entered into selection of the datum and its adopted value. But, the
primary requirement was to minimize the recompilation of national mapping products (Zilkoski et
al. 1992). There was no guarantee that the NAVD 88 datum corresponds to the theoretical level
surface defined by the GRS80 definitions. A recent study by Rapp (1996) compares ITRF93 GPS
positions and a global geopotential model against the NAVD 88 vertical datum. Rapp found a
mean offset for the NAVD88 datum of -27 cm when computed with a set of 397 GPS points.
The sense of the offset is portrayed in Figure 3.
__________________________________________________ Global Geoid Model 27 cm __________________________________________________ NAVD 88 Reference
Figure 3. -- NAVD 88 offset.
Geoid Height Bias
Modern high resolution geoid height models are invariably computed by a remove/restore
technique (Schwarz et al., 1990). In this process, a global geopotential model is evaluated to
obtain base geoid and gravity anomaly grids. Measured gravity data are reduced and the base
gravity anomalies are subtracted in the removal stage. Some type of Fast Fourier Transform
(FFT) technique is used to evaluate Stokes integral, and the residual geoid quantities are added
back to the base geoid grid in the restore stage. However, due to its problematic nature, most
practitioners do not perform trend removal prior to invocation of the FFT. While such trends are
small, their spectrum will be folded, or aliased, across the recoverable frequency band (Hamming
1989, pp. 224-227). This effect is expected to be of long wavelength, and certainly deserves
future study by the geodetic community.
THE GEOID96 AND G96SSS GEOID MODELS
Because of the increasing use of GPS in the United States for both horizontal and vertical positioning, the National Geodetic Survey (NGS) must support the surveying, mapping, navigational, and GIS communities in obtaining heights referred to the NAVD 88 datum using GPS technology. Studies by Milbert (1995) have found that it is possible to relate a given high-resolution gravimetric geoid model to the reference system of GPS ellipsoidal heights and to the vertical datum of an orthometric height system by means of an empirical conversion surface. Such conversion values, s, contain the datum definition and realization problems discussed above. Formally,
It is possible to absorb the datum biases contained in the conversion surface, s, into a gravimetric geoid model, N. If this is done, then a new geoid model, denoted N96, is obtained.
The advantage of such a geoid model is that it will support direct conversion between an ellipsoidal reference system and orthometric vertical datum, even if they are not defined on a common reference. This procedure was followed in GEOID96. If subscripts are used to denote the datums associated with the height systems, then we may write:
The equation shown above is the conversion we supply to our users. The major component of the
datum definition error is the non-geocentricity of NAD 83, illustrated in Figure 2. In essence,
GEOID96 has been defined relative to a non-geocentric ellipsoid. Alternatively, it is correct to
state that GEOID96 is biased with respect to a geocentric ellipsoid. However, this bias is
deliberate. GEOID96 supports the direct conversion between NAD 83 GPS heights and NAVD
88 orthometric heights.
The technique for obtaining the gravimetric geoid model, G96SSS, is to use gravity data to
compute high frequency corrections to an existing model of the Earth's geoid heights. This base
model was obtained by evaluating the new, EGM96, global geopotential model computed by the
joint NASA Goddard Space Flight Center and DoD Defense Mapping Agency project (Rapp and
Nerem 1994). By means of a one-dimensional, spherical FFT algorithm, we computed the high
frequency geoid component from nearly 1.8 million point gravity data in the NGS data base. The
high frequency geoid grid was combined with the EGM96 geoid heights, and a correction derived
from digital terrain data, to yield the final gravimetric geoid heights. We are particularly grateful
for the support of the Defense Mapping Agency in supplying certain gravity and digital terrain
data.
The technique for obtaining the GEOID96 geoid model in the conterminous United States is to compute an empirical conversion surface that is added to the G96SSS model. We first compute the departures of the G96SSS geoid heights from the NAD 83 ellipsoid heights and NAVD 88 orthometric heights at nearly 3000 points. We remove a tilted plane trend, which captures the non-geocentricity of the NAD 83 (86) reference system, as well as vertical datum bias in NAVD 88. Then an empirical covariance function is fit to the covariance statistics of the detrended geoid residuals (Figure 4). The fit is made using a simple function of the form
where d is the spherical distance between points; characteristic length, L = 400 km; and function variance C0 = (9.7)2 cm2. Through collocation, predictions of the detrended residuals are made on a regular grid. In the prediction, GPS heights are assigned a random noise component of 5.8 cm. The trend is then restored to prediction grid, generating the final empirical conversion surface (See Figure 5 for an example). The similarity of the conversion surface and the non-geocentric effect in Figure 2 is evident.
Figure 4. -- Sample empirical covariance function fit.
Figure 5. -- Example of a conversion surface between GEOID96 and G96SSS.
The smoothness of the conversion surface is remarkable. This is directly related to the long characteristic length, L = 400 km, that was obtained in the function fit. The conversion surface incorporates datum definition effects, as well as smoothly varying errors in ellipsoid, orthometric, and geoid height. A shaded relief image of a preliminary version of GEOID96 is shown in 6.
Figure 6. -- Preliminary version of GEOID96 geoid height model.
RESULTS WITH THE GEOID96 PROCEDURE
Our objective has been to develop a geoid model that directly converts between the inconsistent definitions of our height systems. To evaluate a preliminary GEOID96 model, the relationship
was tested at 2729 GPS points on leveled benchmarks. It was found that the RMS error was 5.8
cm, with no offsets or trends removed. Thus, the conversion process is seen to be quite
successful.
Perhaps of even more interest, the covariance statistics for the residuals to the preliminary GEOID96 model were computed, and an empirical covariance function was then developed. These results are portrayed in Figure 7. Unlike Figure 4, which was plotted to a distance of 1000 km, Figure 7 is only plotted out to 100 km. At this much closer scale, a drop is seen in the statistics from 5.8 cm at d = 0, down to 2.6 cm at d = 5 km. This reduction is evidence of an uncorrelated (white-noise) process. The source of the 5.8 cm of uncorrelated error is random error in the GPS ellipsoidal heights. The sources of the 2.6 cm of correlated error are not obvious, but geoid error is certainly one component. Further discussion on the error sources can be found in Milbert (1995).
Figure 7. -- Empirical covariance function fit, preliminary GEOID96 model.
In closing this section, two points must be made. The GEOID96 model does not eliminate the
need for leveled benchmark ties in geodetic surveys. However, one should obtain better results
with adjustment procedures (as described in Milbert 1991) when benchmark distribution is not
ideal. And, it has been found that particular care must be taken to get accurate GPS ellipsoidal
heights. Zilkoski (1996), for example, gives guidelines that address numerous error sources; such
as antenna phase center variation with elevation angle, tropospheric scaling parameters, and
multipathing.
CONCLUSIONS
Gravimetric geoid models, such as GEOID93 or G96SSS, show systematic departures from NAD
83 GPS ellipsoidal heights at leveled benchmarks with NAVD 88 orthometric heights. These
departures are dominated by datum definition and datum realization problems. It is possible to fit
these departures into a very smooth conversion surface, and add this surface to a gravimetric
geoid model. The GEOID96 geoid height model, which incorporates such a conversion surface,
displays about 2.5 cm of accuracy (one sigma) between points spaced at 50 km or greater. GPS
ellipsoidal height error of about 6 cm was observed after the computations.
AVAILABILITY
The geoid height and deflection of the vertical components have a target release date of mid-October 1996. They will be available on a single CD-ROM from the NGS Information Services Branch. GEOID96 is organized into 9 regions; 6 for the conterminous United States, and the remainder for Alaska, Hawaii, Puerto Rico, and the Virgin Islands. The GEOID96 model in the conterminous United States incorporates NAD 83 GPS heights on NAVD 88 benchmarks. For specialized studies, the G96SSS gravimetric geoid model is supplied in 6 regions covering the conterminous United States. The DEFLEC96 model, which is compatible with the GEOID96 model, is organized in 17 regions; spanning the conterminous United States, Alaska, Hawaii, Puerto Rico, and the Virgin Islands. In addition to the CD-ROM, users may obtain regional groupings individually on diskette. These models will also be available for anonymous FTP access at ftp.ngs.noaa.gov; on the World Wide Web at http://www.ngs.noaa.gov; and on the electronic bulletin board system -- telephone 301-713-4181 and 301-713-4182 (8-bit, no parity, 1 stop bit, 300 to 14400 baud). For more information, please contact:
Information Services Branch National Geodetic Survey, NOAA, N/NGS12 1315 East-West Highway, Station 9202 Silver Spring, MD 20910-3282 Phone: 301-713-3242; Fax: 301-713-4172
REFERENCES
Hamming, R. W., 1989: Digital Filters, Third Edition. Prentice-Hall, Inc., Englewood Cliffs, 284
pp.
Milbert, D.G., 1995: Improvement of a high resolution geoid height model in the United States
by GPS height on NAVD 88 benchmarks. In: Balmino G., F. Sanso (ed), New Geoids in the
World, International Association of Geodesy, Bulletin d'Information N. 77, IGeS Bulletin N. 4,
13-36.
Milbert, D. G., 1991: Computing GPS-derived orthometric heights with the GEOID90 geoid
height model. Technical Papers of the 1991 ACSM-ASPRS Fall Convention, Atlanta, Oct. 28 to
Nov. 1, 1991. American Congress on Surveying and Mapping, Washington, D.C., pp. A46-55.
Moritz, H., 1992: Geodetic Reference System 1980. Bull. Geod., 66(2), 187-192.
Rapp, R.H., 1996: Use of potential coefficient models for geoid undulation determinations using
a spherical harmonic representation of the height anomaly/geoid undulation difference. Submitted
to Journal of Geodesy.
Rapp, R. H. and R. S. Nerem, 1994: A joint GSFC/DMA project for improving the model of the
Earth's gravitational field. Presented at Joint Symposium of the International Gravity Commission
and the International Geoid Commission, Graz, Austria, September, 1994.
Schwarz, K.P., M.G. Sideris, and R. Forsberg, 1990: The use of FFT techniques in physical
geodesy. Geophysical Journal International, 100, pp. 485-514.
Zilkoski, D.B., 1996: Guidelines for establishing GPS-derived ellipsoid heights (Standards: 2 cm
and 5 cm), Version 4.1. Internal Draft Document. National Geodetic Survey, Silver Spring, MD.
Zilkoski, D.B., J.H. Richards, and G.M. Young, 1992: Results of the general adjustment of the North American Vertical Datum of 1988. Surv. and Land Info. Sys., 52(3), 133-149.

வடிவம் உட்கிரகங்களின் அளவு ஒப்பீடு (இடமிருந்து வலமாக): புதன், வெள்ளி, புவி மற்றும் செவ்வாய் புவியின் உருவம் துருவங்களில் தட்டையாகவும் நிலநடுக் கோட்டிற்கு அருகில் விரிவடைந்தும் உள்ள நீள்வட்ட கோளத்தைப் போல் காணப்படுகின்றது. புவியின் சுழற்சியால் இந்த இடை விரிவாக்கம் ஏற்பட்டுள்ளது, மேலும் விட்டங்களை ஒப்பிடுகையில் நிலநடுக்கோடு துருவங்களை விட 43 கிமீ அதிகமாயுள்ளது. இக் கோளத்தின் சராசரி விட்டம் 12,742 கிமீ (7,918 மைல்) அதாவது 40,000 கிமீ/π, ஏனென்றால் மீட்டரை முதலில் வரையறுக்கும் போது அது பூமத்திய ரேகையிலிருந்து வட துருவத்திற்கு பிரான்ஸில் உள்ள பாரிஸ் நகர வழியாக கணக்கிடும் தூரத்தில் 1/10,000,000 ஈடாக கொள்ளப்பட்டது.

வடிவம் உட்கிரகங்களின் அளவு ஒப்பீடு (இடமிருந்து வலமாக): புதன், வெள்ளி, புவி மற்றும் செவ்வாய் புவியின் உருவம் துருவங்களில் தட்டையாகவும் நிலநடுக் கோட்டிற்கு அருகில் விரிவடைந்தும் உள்ள நீள்வட்ட கோளத்தைப் போல் காணப்படுகின்றது.

புவியின் சுழற்சியால் இந்த இடை விரிவாக்கம் ஏற்பட்டுள்ளது, மேலும் விட்டங்களை ஒப்பிடுகையில் நிலநடுக்கோடு துருவங்களை விட 43 கிமீ அதிகமாயுள்ளது. இக் கோளத்தின் சராசரி விட்டம் 12,742 கிமீ (7,918 மைல்) அதாவது 40,000 கிமீ/π, ஏனென்றால் மீட்டரை முதலில் வரையறுக்கும் போது அது பூமத்திய ரேகையிலிருந்து வட துருவத்திற்கு பிரான்ஸில் உள்ள பாரிஸ் நகர வழியாக கணக்கிடும் தூரத்தில் 1/10,000,000 ஈடாக கொள்ளப்பட்டது.

Thus, the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape. The rainfall of the fountain has caused this area to disappear, and it is more than 43 km higher than the rainfall by stopping the rainfall. The rainfall of the fountain is 12,742 km (7,918 miles) or 40,000 km/h, since when the rainfall was first reached, it was entered 1/10,000,000 in the distance from the earthquake to the north of the railway to the Paris city road in Brunswick.

Thus, the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape of the shape.

The rainfall of the fountain has caused this area to disappear, and it is more than 43 km higher than the rainfall by stopping the rainfall. The rainfall of the fountain is 12,742 km (7,918 miles) or 40,000 km/h, since when the rainfall was first reached, it was entered 1/10,000,000 in the distance from the earthquake to the north of the railway to the Paris city road in Brunswick.

|Information
at the foundation of modern science and technology from the Physical Measurement
Laboratory of
NIST
|
Note
In the meantime, users may refer to the Bureau International des Poids et Mesures (BIPM) website. Now that the 9th edition of the SI Brochure (2019) has been made available, we are in the process of revising SP 330, SP 811, and the contents of this site.
Essentials of the SI
Introduction
SI units and prefixes
Units outside the SI
Rules and style conventions
Background
Bibliography
Detailed contents | About
this reference | Feedback
Privacy Policy / Security Notice | NIST Disclaimer
Online: February 1998 - Last update: June 2019

The bulk turns to the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk.

புவி அதன் இடவமைப்பான (topography) சிறு மேடு பள்ளங்களை வைத்து காணும் போது கோள வடிவிலிருந்து புவி மாறுபடும் ஆனால் மொத்தத்தில் இந்த வேறுபாடு மிகவும் சிறியது: உண்மையான கோளத்தோடு ஒப்பிடுகையில் புவி 584 அல்லது 0.17% விலகியுள்ளது, இது பில்லியர்ட்ஸ் விளையாட்டில் பயன்படுத்தப்படும் பில்லியர்ட் பந்திற்கு ஏற்றுக் கொள்ளக்கூடிய 0.22% மாற்றத்தை விட சிறியதே. புவியின் மேற்பரப்பில் மிக அதிகமாக கோள வடிவிலிருந்து விலகியுள்ள இரு இடங்கள் எவரஸ்ட் சிகரம் (கடல் மட்டத்திலிருந்து 8,848 உயரம்) மற்றும் மரியானா ட்ரென்ச் (கடல் மட்டத்திலிருந்து 10,911 மீ கீழுள்ளது).

புவி அதன் இடவமைப்பான (topography) சிறு மேடு பள்ளங்களை வைத்து காணும் போது கோள வடிவிலிருந்து புவி மாறுபடும் ஆனால் மொத்தத்தில் இந்த வேறுபாடு மிகவும் சிறியது: உண்மையான கோளத்தோடு ஒப்பிடுகையில் புவி 584 அல்லது 0.17% விலகியுள்ளது, இது பில்லியர்ட்ஸ் விளையாட்டில் பயன்படுத்தப்படும் பில்லியர்ட் பந்திற்கு ஏற்றுக் கொள்ளக்கூடிய 0.22% மாற்றத்தை விட சிறியதே. புவியின் மேற்பரப்பில் மிக அதிகமாக கோள வடிவிலிருந்து விலகியுள்ள இரு இடங்கள் எவரஸ்ட் சிகரம் (கடல் மட்டத்திலிருந்து 8,848 உயரம்) மற்றும் மரியானா ட்ரென்ச் (கடல் மட்டத்திலிருந்து 10,911 மீ கீழுள்ளது).

The bulk turns to the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk.

The bulk turns to the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk of the bulk.

The surface of the earth is 5.98 cc.

Earth, thumbnail (32.1%), oxygen (30.1%), amygdala (15.1%), mechanics (13.9%), sulphur (2.9%), nitrogen (1.8%), chloride (1.5%), and amygdala (1.4%); the lower 1.2% were very low-dimensional individuals.

Question: what is the surface of the earth

5.98 கி.கி . ஆகும் .

The surface of the earth is 5.98 cc.

Earth, thumbnail (32.1%), oxygen (30.1%), amygdala (15.1%), mechanics (13.9%), sulphur (2.9%), nitrogen (1.8%), chloride (1.5%), and amygdala (1.4%); the lower 1.2% were very low-dimensional individuals.

Question: what percentage of the earths amygdala is located in the amygdala

The surface of the earth is 5.98 cc.

what percentage of the earths amygdala is located in the amygdala

Question: what percentage of earths surface is made up of thumbnail

The surface of the earth is 5.98 cc.

what percentage of earths surface is made up of thumbnail

Question: what percentage of the earths surface is amygdala

The surface of the earth is 5.98 cc.

what percentage of the earths surface is amygdala

Question: what percentage of the earths surface is mechanics

% ) , மெக்னீஷியம் ( 13.9

The surface of the earth is 5.98 cc.

what percentage of the earths surface is mechanics

Question: what percentage of earths surface is oxygen

The surface of the earth is 5.98 cc.

what percentage of earths surface is oxygen

Question: what percentage of the earths surface is chloride

% ) , கால்சியம் ( 1.5

The surface of the earth is 5.98 cc.

what percentage of the earths surface is chloride

Question: what percentage of earths surface is nitrogen

% ) , நிக்கல் ( 1.8

The surface of the earth is 5.98 cc.

what percentage of earths surface is nitrogen

Earth , thumbnail ( 32.1 % ) , oxygen ( 30.1 % ) , amygdala ( 15.1 % ) , mechanics ( 13.9 % ) , sulphur ( 2.9 % ) , nitrogen ( 1.8 % ) , chloride ( 1.5 % ) , and amygdala ( 1.4 % ) ; the lower 1.2 % were very low - dimensional individuals .

புவியின் இரசாயன சேர்மானம் பூமியின் நிறை ஏறக்குறைய 5.98 கி.கி. ஆகும். பூமி, இரும்பு (32.1%), ஆக்சிஜன் (30.1%), சிலிக்கன் (15.1%), மெக்னீஷியம் (13.9%), சல்பர் (2.9%), நிக்கல் (1.8%), கால்சியம் (1.5%), மற்றும் அலுமினியம் (1.4%); மீதமுள்ள 1.2% மிகவும் குறைந்த அளவிலுள்ள தனிமங்களால் ஆனது.

புவியின் இரசாயன சேர்மானம் பூமியின் நிறை ஏறக்குறைய 5.98 கி.கி. ஆகும்.

பூமி, இரும்பு (32.1%), ஆக்சிஜன் (30.1%), சிலிக்கன் (15.1%), மெக்னீஷியம் (13.9%), சல்பர் (2.9%), நிக்கல் (1.8%), கால்சியம் (1.5%), மற்றும் அலுமினியம் (1.4%); மீதமுள்ள 1.2% மிகவும் குறைந்த அளவிலுள்ள தனிமங்களால் ஆனது.

The surface of the earth is 5.98 cc. Earth, thumbnail (32.1%), oxygen (30.1%), amygdala (15.1%), mechanics (13.9%), sulphur (2.9%), nitrogen (1.8%), chloride (1.5%), and amygdala (1.4%); the lower 1.2% were very low-dimensional individuals.

Earth, thumbnail (32.1%), oxygen (30.1%), amygdala (15.1%), mechanics (13.9%), sulphur (2.9%), nitrogen (1.8%), chloride (1.5%), and amygdala (1.4%); the lower 1.2% were very low-dimensional individuals.

The heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth.

The isodones that generate higher heat on Earth are Mantathyum-40, Yereum-238, Yereum-235 and Pear-232 .

Radioactive potassium may be major heat source in Earth's core
BERKELEY – Radioactive potassium, common enough on Earth to make potassium-rich bananas one of the "hottest" foods around, appears also to be a substantial source of heat in the Earth's core, according to recent experiments by University of California, Berkeley, geophysicists.
Radioactive potassium, uranium and thorium are thought to be the three main sources of heat in the Earth's interior, aside from that generated by the formation of the planet. Together, the heat keeps the mantle actively churning and the core generating a protective magnetic field.
But geophysicists have found much less potassium in the Earth's crust and mantle than would be expected based on the composition of rocky meteors that supposedly formed the Earth. If, as some have proposed, the missing potassium resides in the Earth's iron core, how did an element as light as potassium get there, especially since iron and potassium don't mix?
Kanani Lee, who recently earned her Ph.D. from UC Berkeley, and UC Berkeley professor of earth and planetary science Raymond Jeanloz have discovered a possible answer. They've shown that at the high pressures and temperatures in the Earth's interior, potassium can form an alloy with iron never before observed. During the planet's formation, this potassium-iron alloy could have sunk to the core, depleting potassium in the overlying mantle and crust and providing a radioactive potassium heat source in addition to that supplied by uranium and thorium in the core.
Lee created the new alloy by squeezing iron and potassium between the tips of two diamonds to temperatures and pressures characteristic of 600-700 kilometers below the surface - 2,500 degrees Celsius and nearly 4 million pounds per square inch, or a quarter of a million times atmospheric pressure.
"Our new findings indicate that the core may contain as much as 1,200 parts per million potassium -just over one tenth of one percent," Lee said. "This amount may seem small, and is comparable to the concentration of radioactive potassium naturally present in bananas. Combined over the entire mass of the Earth's core, however, it can be enough to provide one-fifth of the heat given off by the Earth."
Lee and Jeanloz will report their findings on Dec. 10, at the American Geophysical Union meeting in San Francisco, and in an article accepted for publication in Geophysical Research Letters.
"With one experiment, Lee and Jeanloz demonstrated that potassium may be an important heat source for the geodynamo, provided a way out of some troublesome aspects of the core's thermal evolution, and further demonstrated that modern computational mineral physics not only complements experimental work, but that it can provide guidance to fruitful experimental explorations," said Mark Bukowinski, professor of earth and planetary science at UC Berkeley, who predicted the unusual alloy in the mid-1970s.
Geophysicist Bruce Buffett of the University of Chicago cautions that more experiments need to be done to show that iron can actually pull potassium away from the silicate rocks that dominate in the Earth's mantle.
"They proved it would be possible to dissolve potassium into liquid iron," Buffet said. "Modelers need heat, so this is one source, because the radiogenic isotope of potassium can produce heat and that can help power convection in the core and drive the magnetic field. They proved it could go in. What's important is how much is pulled out of the silicate. There's still work to be done "
If a significant amount of potassium does reside in the Earth's core, this would clear up a lingering question - why the ratio of potassium to uranium in stony meteorites (chondrites), which presumably coalesced to form the Earth, is eight times greater than the observed ratio in the Earth's crust. Though some geologists have asserted that the missing potassium resides in the core, there was no mechanism by which it could have reached the core. Other elements like oxygen and carbon form compounds or alloys with iron and presumably were dragged down by iron as it sank to the core. But at normal temperature and pressure, potassium does not associate with iron.
Others have argued that the missing potassium boiled away during the early, molten stage of Earth's evolution.
The demonstration by Lee and Jeanloz that potassium can dissolve in iron to form an alloy provides an explanation for the missing potassium.
"Early in Earth's history, the interior temperature and pressure would not have been high enough to make this alloy," Lee said. "But as more and more meteorites piled on, the pressure and temperature would have increased to the point where this alloy could form."
The existence of this high-pressure alloy was predicted by Bukowinski in the mid-1970s. Using quantum mechanical arguments, he suggested that high pressure would squeeze potassium's lone outer electron into a lower shell, making the atom resemble iron and thus more likely to alloy with iron.
More recent quantum mechanical calculations using improved techniques, conducted with Gerd Steinle-Neumann at the Universität Bayreuth's Bayerisches Geoinstitüt, confirmed the new experimental measurements.
"This really replicates and verifies the earlier calculations 26 years ago and provides a physical explanation for our experimental results," Jeanloz said.
The Earth is thought to have formed from the collision of many rocky asteroids, perhaps hundreds of kilometers in diameter, in the early solar system. As the proto-Earth gradually bulked up, continuing asteroid collisions and gravitational collapse kept the planet molten. Heavier elements - in particular iron - would have sunk to the core in 10 to 100 million years' time, carrying with it other elements that bind to iron.
Gradually, however, the Earth would have cooled off and become a dead rocky globe with a cold iron ball at the core if not for the continued release of heat by the decay of radioactive elements like potassium-40, uranium-238 and thorium-232, which have half-lives of 1.25 billion, 4 billion and 14 billion years, respectively. About one in every thousand potassium atoms is radioactive.
The heat generated in the core turns the iron into a convecting dynamo that maintains a magnetic field strong enough to shield the planet from the solar wind. This heat leaks out into the mantle, causing convection in the rock that moves crustal plates and fuels volcanoes.
Balancing the heat generated in the core with the known concentrations of radiogenic isotopes has been difficult, however, and the missing potassium has been a big part of the problem. One researcher proposed earlier this year that sulfur could help potassium associate with iron and provide a means by which potassium could reach the core.
The experiment by Lee and Jeanloz shows that sulfur is not necessary. Lee combined pure iron and pure potassium in a diamond anvil cell and squeezed the small sample to 26 gigapascals of pressure while heating the sample with a laser above 2,500 Kelvin (4,000 degrees Fahrenheit), which is above the melting points of both potassium and iron. She conducted this experiment six times in the high-intensity X-ray beams of two different accelerators - Lawrence Berkeley National Laboratory's Advanced Light Source and the Stanford Synchrotron Radiation Laboratory - to obtain X-ray diffraction images of the samples' internal structure. The images confirmed that potassium and iron had mixed evenly to form an alloy, much as iron and carbon mix to form steel alloy.
In the theoretical magma ocean of a proto-Earth, the pressure at a depth of 400-1,000 kilometers (270-670 miles) would be between 15 and 35 gigapascals and the temperature would be 2,200-3,000 Kelvin, Jeanloz said.
"At these temperatures and pressures, the underlying physics changes and the electron density shifts, making potassium look more like iron," Jeanloz said. "At high pressure, the periodic table looks totally different."
"The work by Lee and Jeanloz provides the first proof that potassium is indeed miscible in iron at high pressures and, perhaps as significantly, it further vindicates the computational physics that underlies the original prediction," Bukowinski said. "If it can be further demonstrated that potassium would enter iron in significant amounts in the presence of silicate minerals, conditions representative of likely core formation processes, then potassium could provide the extra heat needed to explain why the Earth's inner core hasn't frozen to as large a size as the thermal history of the core suggests it should."
Jeanloz is excited by the fact that theoretical calculations are now not only explaining experimental findings at high pressure, but also predicting structures.
"We need theorists to identify interesting problems, not only check our results after the experiment," he said. "That's happening now. In the past half a dozen years, theorists have been making predictions that experimentalists are willing to spend a few years to demonstrate."
The work was funded by the National Science Foundation and the Department of Energy.

பூமியின் வெப்பம் பூமியின் உட்புற வெப்பம் கிரகச் சேர்க்கையினால் உண்டாகும் மீத வெப்பத்தாலும் (சுமார் 20%) மற்றும் அணுச் சிதைவுகளாலும் (80%) உருவானது. பூமியில் அதிகமான வெப்பத்தை உருவாக்கும் ஐசோடோப்புகள் பொட்டாசியம்-40, யுரேனியம்-238, யுரேனியம்-235 மற்றும் தோரியம்-232 ஆகும்.

பூமியின் வெப்பம் பூமியின் உட்புற வெப்பம் கிரகச் சேர்க்கையினால் உண்டாகும் மீத வெப்பத்தாலும் (சுமார் 20%) மற்றும் அணுச் சிதைவுகளாலும் (80%) உருவானது.

பூமியில் அதிகமான வெப்பத்தை உருவாக்கும் ஐசோடோப்புகள் பொட்டாசியம்-40, யுரேனியம்-238, யுரேனியம்-235 மற்றும் தோரியம்-232 ஆகும்.

The heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth. The isodones that generate higher heat on Earth are Mantathyum-40, Yereum-238, Yereum-235 and Pear-232 .

The heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth and the heat of the earth is the heat of the earth.

The isodones that generate higher heat on Earth are Mantathyum-40, Yereum-238, Yereum-235 and Pear-232 .

The temperature of the earth is 7,000 km2 and the temperature is 360 kPa (GPa).

ஐசோடோப்புகள்

பொட்டாசியம்-40

யுரேனியம்-238

யுரேனியம்-235

கெல்வினையும்

Question: what is the temperature of the earth

The isodones that generate higher heat on Earth are Mantathyum-40, Yereum-238, Yereum-235 and Pear-232 .

The temperature of the earth is 7,000 km2 and the temperature is 360 kPa (GPa).

Question: what is the gpaa of earth

Question: what type of animal generates more heat on earth

ஐசோடோப்புகள்

what type of animal generates more heat on earth

Question: what is the earth's temperature

360 கிகாபா ( GPa)-வையும்

Question: what is the gpa of the earth

Question: what is the name of the isodones that generate higher heat on earth

what is the name of the isodones that generate higher heat on earth

Question: what type of animals generate more heat on earth

ஐசோடோப்புகள்

what type of animals generate more heat on earth

Question: what are some of the isodones that generate higher heat on earth

Mantathyum-40, Yereum-238, Yereum-235 and Pear-232

what are some of the isodones that generate higher heat on earth

The isodones that generate higher heat on Earth are Mantathyum-40 , Yereum-238 , Yereum-235 and Pear-232 .

The temperature of the earth is 7,000 km2 and the temperature is 360 kPa ( GPa ) .

பூமியில் அதிகமான வெப்பத்தை உருவாக்கும் ஐசோடோப்புகள் பொட்டாசியம்-40, யுரேனியம்-238, யுரேனியம்-235 மற்றும் தோரியம்-232 ஆகும். பூமியின் மத்தியில் வெப்பம் 7,000 கெல்வினையும் மற்றும் அழுத்தம் 360 கிகாபா (GPa)-வையும் அடையலாம்.

பூமியின் மத்தியில் வெப்பம் 7,000 கெல்வினையும் மற்றும் அழுத்தம் 360 கிகாபா (GPa)-வையும் அடையலாம்.

The isodones that generate higher heat on Earth are Mantathyum-40, Yereum-238, Yereum-235 and Pear-232 . The temperature of the earth is 7,000 km2 and the temperature is 360 kPa (GPa).

The temperature of the earth is 7,000 km2 and the temperature is 360 kPa (GPa).

The total heat loss arising from the earth 163 a portion of the heat is transmitted to the threshold by the threshold of the threshold (mantle plumes) in the threshold of the threshold; this may be a portion of the threshold. This threshold will not cause the threshold of the threshold or the threshold of the threshold.

பூமியிலிருந்து

மூடகத்திற்கு

கடத்தப்படுகிறது

மையங்களையும்

வெள்ளத்தையும்

ஏற்படுத்தவல்லது

Flood Basalts and Hot-Spot Tracks: Plume Heads and Tails
Abstract
Continental flood basalt eruptions have resulted in sudden and massive accumulations of basaltic lavas in excess of any contemporary volcanic processes. The largest flood basalt events mark the earliest volcanic activity of many major hot spots, which are thought to result from deep mantle plumes. The relative volumes of melt and eruption rates of flood basalts and hot spots as well as their temporal and spatial relations can be explained by a model of mantle plume initiation: Flood basalts represent plume ``heads'' and hot spots represent continuing magmatism associated with the remaining plume conduit or ``tail.'' Continental rifting is not required, although it commonly follows flood basalt volcanism, and flood basalt provinces may occur as a natural consequence of the initiation of hot-spot activity in ocean basins as well as on continents.
- Publication:
- Science
- Pub Date:
- October 1989
- DOI:
- 10.1126/science.246.4926.103
- Bibcode:
- 1989Sci...246..103R

Question: what is another name for the threshold of the earth's heat loss

The total heat loss arising from the earth 163 a portion of the heat is transmitted to the threshold by the threshold of the threshold (mantle plumes) in the threshold of the threshold; this may be a portion of the threshold. This threshold will not cause the threshold of the threshold or the threshold of the threshold.

what is another name for the threshold of the earth's heat loss

Question: how much of the earth's heat is transmitted to the threshold

how much of the earth's heat is transmitted to the threshold

Question: how much of the earth's heat is transmitted to the threshold by mantle plumes

how much of the earth's heat is transmitted to the threshold by mantle plumes

Question: what is the threshold of which the heat is transferred to

mantle plumes) in the threshold of the threshold

mantle plumes ) மூலமாக மூடகத்திற்கு கடத்தப்படுகிறது ; இது ஒருவகை

mantle plumes ) in the threshold of the threshold

what is the threshold of which the heat is transferred to

Question: where does the majority of the earths heat come from

பூமியிலிருந்து ஏற்படும் மொத்த வெப்ப இழப்பு 163

where does the majority of the earths heat come from

Question: what is the heat loss from the earth called

ஏற்படும் மொத்த வெப்ப இழப்பு

what is the heat loss from the earth called

Question: what is the source of most of the earths heat

பூமியிலிருந்து

what is the source of most of the earths heat

Question: what type of heat is generated by earths mantle plumes

மொத்த வெப்ப இழப்பு

what type of heat is generated by earths mantle plumes

The total heat loss arising from the earth 163 a portion of the heat is transmitted to the threshold by the threshold of the threshold ( mantle plumes ) in the threshold of the threshold ; this may be a portion of the threshold . This threshold will not cause the threshold of the threshold or the threshold of the threshold .

பூமியிலிருந்து ஏற்படும் மொத்த வெப்ப இழப்பு 163 உட்கருவின் வெப்ப ஆற்றலில் ஒரு பகுதி மூடக ஆழ் கிணறுகளின் (mantle plumes) மூலமாக மூடகத்திற்கு கடத்தப்படுகிறது; இது ஒருவகை அதி வெப்பப் பாறை எனலாம். இந்த வெப்ப ஆழ் கிணறுகள் வெப்ப மையங்களையும் வெப்ப பாறை வெள்ளத்தையும் ஏற்படுத்தவல்லது.

பூமியிலிருந்து ஏற்படும் மொத்த வெப்ப இழப்பு 163 உட்கருவின் வெப்ப ஆற்றலில் ஒரு பகுதி மூடக ஆழ் கிணறுகளின் (mantle plumes) மூலமாக மூடகத்திற்கு கடத்தப்படுகிறது; இது ஒருவகை அதி வெப்பப் பாறை எனலாம். இந்த வெப்ப ஆழ் கிணறுகள் வெப்ப மையங்களையும் வெப்ப பாறை வெள்ளத்தையும் ஏற்படுத்தவல்லது.

The total heat loss arising from the earth 163 a portion of the heat is transmitted to the threshold by the threshold of the threshold (mantle plumes) in the threshold of the threshold; this may be a portion of the threshold. This threshold will not cause the threshold of the threshold or the threshold of the threshold.

The total heat loss arising from the earth 163 a portion of the heat is transmitted to the threshold by the threshold of the threshold (mantle plumes) in the threshold of the threshold; this may be a portion of the threshold. This threshold will not cause the threshold of the threshold or the threshold of the threshold.

See:78.0 Antarctic Gate60.9 Antarctic Gate47.2 North American Gate67.8 North American Gate75.9 South American Gate43.6 Basque Gate103.3 is known as the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range.

Scientists now have a fairly good understanding of how the plates move and how such movements relate to earthquake activity. Most movement occurs along narrow zones between plates where the results of plate-tectonic forces are most evident.
There are four types of plate boundaries:
Divergent boundaries occur along spreading centers where plates are moving apart and new crust is created by magma pushing up from the mantle. Picture two giant conveyor belts, facing each other but slowly moving in opposite directions as they transport newly formed oceanic crust away from the ridge crest.
Perhaps the best known of the divergent boundaries is the Mid-Atlantic Ridge. This submerged mountain range, which extends from the Arctic Ocean to beyond the southern tip of Africa, is but one segment of the global mid-ocean ridge system that encircles the Earth. The rate of spreading along the Mid-Atlantic Ridge averages about 2.5 centimeters per year (cm/yr), or 25 km in a million years. This rate may seem slow by human standards, but because this process has been going on for millions of years, it has resulted in plate movement of thousands of kilometers. Seafloor spreading over the past 100 to 200 million years has caused the Atlantic Ocean to grow from a tiny inlet of water between the continents of Europe, Africa, and the Americas into the vast ocean that exists today.
The volcanic country of Iceland, which straddles the Mid-Atlantic Ridge, offers scientists a natural laboratory for studying on land the processes also occurring along the submerged parts of a spreading ridge. Iceland is splitting along the spreading center between the North American and Eurasian Plates, as North America moves westward relative to Eurasia.
Map showing the Mid-Atlantic Ridge splitting Iceland and separating the North American and Eurasian Plates. The map also shows Reykjavik, the capital of Iceland, the Thingvellir area, and the locations of some of Iceland's active volcanoes (red triangles), including Krafla.
The consequences of plate movement are easy to see around Krafla Volcano, in the northeastern part of Iceland. Here, existing ground cracks have widened and new ones appear every few months. From 1975 to 1984, numerous episodes of rifting (surface cracking) took place along the Krafla fissure zone. Some of these rifting events were accompanied by volcanic activity; the ground would gradually rise 1-2 m before abruptly dropping, signalling an impending eruption. Between 1975 and 1984, the displacements caused by rifting totalled about 7 m.
In East Africa, spreading processes have already torn Saudi Arabia away from the rest of the African continent, forming the Red Sea. The actively splitting African Plate and the Arabian Plate meet in what geologists call a triple junction, where the Red Sea meets the Gulf of Aden. A new spreading center may be developing under Africa along the East African Rift Zone. When the continental crust stretches beyond its limits, tension cracks begin to appear on the Earth's surface. Magma rises and squeezes through the widening cracks, sometimes to erupt and form volcanoes. The rising magma, whether or not it erupts, puts more pressure on the crust to produce additional fractures and, ultimately, the rift zone.
East Africa may be the site of the Earth's next major ocean. Plate interactions in the region provide scientists an opportunity to study first hand how the Atlantic may have begun to form about 200 million years ago. Geologists believe that, if spreading continues, the three plates that meet at the edge of the present-day African continent will separate completely, allowing the Indian Ocean to flood the area and making the easternmost corner of Africa (the Horn of Africa) a large island.
The size of the Earth has not changed significantly during the past 600 million years, and very likely not since shortly after its formation 4.6 billion years ago. The Earth's unchanging size implies that the crust must be destroyed at about the same rate as it is being created, as Harry Hess surmised. Such destruction (recycling) of crust takes place along convergent boundaries where plates are moving toward each other, and sometimes one plate sinks (is subducted) under another. The location where sinking of a plate occurs is called a subduction zone.
The type of convergence -- called by some a very slow "collision" -- that takes place between plates depends on the kind of lithosphere involved. Convergence can occur between an oceanic and a largely continental plate, or between two largely oceanic plates, or between two largely continental plates.
If by magic we could pull a plug and drain the Pacific Ocean, we would see a most amazing sight -- a number of long narrow, curving trenches thousands of kilometers long and 8 to 10 km deep cutting into the ocean floor. Trenches are the deepest parts of the ocean floor and are created by subduction.
Off the coast of South America along the Peru-Chile trench, the oceanic Nazca Plate is pushing into and being subducted under the continental part of the South American Plate. In turn, the overriding South American Plate is being lifted up, creating the towering Andes mountains, the backbone of the continent. Strong, destructive earthquakes and the rapid uplift of mountain ranges are common in this region. Even though the Nazca Plate as a whole is sinking smoothly and continuously into the trench, the deepest part of the subducting plate breaks into smaller pieces that become locked in place for long periods of time before suddenly moving to generate large earthquakes. Such earthquakes are often accompanied by uplift of the land by as much as a few meters.
On 9 June 1994, a magnitude-8.3 earthquake struck about 320 km northeast of La Paz, Bolivia, at a depth of 636 km. This earthquake, within the subduction zone between the Nazca Plate and the South American Plate, was one of deepest and largest subduction earthquakes recorded in South America. Fortunately, even though this powerful earthquake was felt as far away as Minnesota and Toronto, Canada, it caused no major damage because of its great depth.
Oceanic-continental convergence also sustains many of the Earth's active volcanoes, such as those in the Andes and the Cascade Range in the Pacific Northwest. The eruptive activity is clearly associated with subduction, but scientists vigorously debate the possible sources of magma: Is magma generated by the partial melting of the subducted oceanic slab, or the overlying continental lithosphere, or both?
As with oceanic-continental convergence, when two oceanic plates converge, one is usually subducted under the other, and in the process a trench is formed. The Marianas Trench (paralleling the Mariana Islands), for example, marks where the fast-moving Pacific Plate converges against the slower moving Philippine Plate. The Challenger Deep, at the southern end of the Marianas Trench, plunges deeper into the Earth's interior (nearly 11,000 m) than Mount Everest, the world's tallest mountain, rises above sea level (about 8,854 m).
Subduction processes in oceanic-oceanic plate convergence also result in the formation of volcanoes. Over millions of years, the erupted lava and volcanic debris pile up on the ocean floor until a submarine volcano rises above sea level to form an island volcano. Such volcanoes are typically strung out in chains called island arcs. As the name implies, volcanic island arcs, which closely parallel the trenches, are generally curved. The trenches are the key to understanding how island arcs such as the Marianas and the Aleutian Islands have formed and why they experience numerous strong earthquakes. Magmas that form island arcs are produced by the partial melting of the descending plate and/or the overlying oceanic lithosphere. The descending plate also provides a source of stress as the two plates interact, leading to frequent moderate to strong earthquakes.
The Himalayan mountain range dramatically demonstrates one of the most visible and spectacular consequences of plate tectonics. When two continents meet head-on, neither is subducted because the continental rocks are relatively light and, like two colliding icebergs, resist downward motion. Instead, the crust tends to buckle and be pushed upward or sideways. The collision of India into Asia 50 million years ago caused the Indian and Eurasian Plates to crumple up along the collision zone. After the collision, the slow continuous convergence of these two plates over millions of years pushed up the Himalayas and the Tibetan Plateau to their present heights. Most of this growth occurred during the past 10 million years. The Himalayas, towering as high as 8,854 m above sea level, form the highest continental mountains in the world. Moreover, the neighboring Tibetan Plateau, at an average elevation of about 4,600 m, is higher than all the peaks in the Alps except for Mont Blanc and Monte Rosa, and is well above the summits of most mountains in the United States.
Above: The collision between the Indian and Eurasian plates has pushed up the Himalayas and the Tibetan Plateau. Below: Cartoon cross sections showing the meeting of these two plates before and after their collision. The reference points (small squares) show the amount of uplift of an imaginary point in the Earth's crust during this mountain-building process.
The zone between two plates sliding horizontally past one another is called a transform-fault boundary, or simply a transform boundary. The concept of transform faults originated with Canadian geophysicist J. Tuzo Wilson, who proposed that these large faults or fracture zones connect two spreading centers (divergent plate boundaries) or, less commonly, trenches (convergent plate boundaries). Most transform faults are found on the ocean floor. They commonly offset the active spreading ridges, producing zig-zag plate margins, and are generally defined by shallow earthquakes. However, a few occur on land, for example the San Andreas fault zone in California. This transform fault connects the East Pacific Rise, a divergent boundary to the south, with the South Gorda -- Juan de Fuca -- Explorer Ridge, another divergent boundary to the north.
The Blanco, Mendocino, Murray, and Molokai fracture zones are some of the many fracture zones (transform faults) that scar the ocean floor and offset ridges (see text). The San Andreas is one of the few transform faults exposed on land.
The San Andreas fault zone, which is about 1,300 km long and in places tens of kilometers wide, slices through two thirds of the length of California. Along it, the Pacific Plate has been grinding horizontally past the North American Plate for 10 million years, at an average rate of about 5 cm/yr. Land on the west side of the fault zone (on the Pacific Plate) is moving in a northwesterly direction relative to the land on the east side of the fault zone (on the North American Plate).
Oceanic fracture zones are ocean-floor valleys that horizontally offset spreading ridges; some of these zones are hundreds to thousands of kilometers long and as much as 8 km deep. Examples of these large scars include the Clarion, Molokai, and Pioneer fracture zones in the Northeast Pacific off the coast of California and Mexico. These zones are presently inactive, but the offsets of the patterns of magnetic striping provide evidence of their previous transform-fault activity.
Not all plate boundaries are as simple as the main types discussed above. In some regions, the boundaries are not well defined because the plate-movement deformation occurring there extends over a broad belt (called a plate-boundary zone). One of these zones marks the Mediterranean-Alpine region between the Eurasian and African Plates, within which several smaller fragments of plates (microplates) have been recognized. Because plate-boundary zones involve at least two large plates and one or more microplates caught up between them, they tend to have complicated geological structures and earthquake patterns.
We can measure how fast tectonic plates are moving today, but how do scientists know what the rates of plate movement have been over geologic time? The oceans hold one of the key pieces to the puzzle. Because the ocean-floor magnetic striping records the flip-flops in the Earth's magnetic field, scientists, knowing the approximate duration of the reversal, can calculate the average rate of plate movement during a given time span. These average rates of plate separations can range widely. The Arctic Ridge has the slowest rate (less than 2.5 cm/yr), and the East Pacific Rise near Easter Island, in the South Pacific about 3,400 km west of Chile, has the fastest rate (more than 15 cm/yr).
Evidence of past rates of plate movement also can be obtained from geologic mapping studies. If a rock formation of known age -- with distinctive composition, structure, or fossils -- mapped on one side of a plate boundary can be matched with the same formation on the other side of the boundary, then measuring the distance that the formation has been offset can give an estimate of the average rate of plate motion. This simple but effective technique has been used to determine the rates of plate motion at divergent boundaries, for example the Mid-Atlantic Ridge, and transform boundaries, such as the San Andreas Fault.
Current plate movement can be tracked directly by means of ground-based or space-based geodetic measurements; geodesy is the science of the size and shape of the Earth. Ground-based measurements are taken with conventional but very precise ground-surveying techniques, using laser-electronic instruments. However, because plate motions are global in scale, they are best measured by satellite-based methods. The late 1970s witnessed the rapid growth of space geodesy, a term applied to space-based techniques for taking precise, repeated measurements of carefully chosen points on the Earth's surface separated by hundreds to thousands of kilometers. The three most commonly used space-geodetic techniques -- very long baseline interferometry (VLBI), satellite laser ranging (SLR), and the Global Positioning System (GPS) -- are based on technologies developed for military and aerospace research, notably radio astronomy and satellite tracking.
Among the three techniques, to date the GPS has been the most useful for studying the Earth's crustal movements. Twenty-one satellites are currently in orbit 20,000 km above the Earth as part of the NavStar system of the U.S. Department of Defense. These satellites continuously transmit radio signals back to Earth. To determine its precise position on Earth (longitude, latitude, elevation), each GPS ground site must simultaneously receive signals from at least four satellites, recording the exact time and location of each satellite when its signal was received. By repeatedly measuring distances between specific points, geologists can determine if there has been active movement along faults or between plates. The separations between GPS sites are already being measured regularly around the Pacific basin. By monitoring the interaction between the Pacific Plate and the surrounding, largely continental plates, scientists hope to learn more about the events building up to earthquakes and volcanic eruptions in the circum-Pacific Ring of Fire. Space-geodetic data have already confirmed that the rates and direction of plate movement, averaged over several years, compare well with rates and direction of plate movement averaged over millions of years.
URL: https://pubs.usgs.gov/publications/text/understanding.html
Last updated: 09.15.14
Contact: bhanks@usgs.gov

See:78.0 Antarctic Gate60.9 Antarctic Gate47.2 North American Gate67.8 North American Gate75.9 South American Gate43.6 Basque Gate103.3 is known as the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range.

See:78.0 Antarctic Gate60.9 Antarctic Gate47.2 North American Gate67.8 North American Gate75.9 South American Gate43.6 Basque Gate103.3 is known as the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range of the highest range.

These arms contain end-to-end systems and also create arms with three kinds of arms: the arms that cross the way, the two arms to one to the other, the arms to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other.

Those who are in the midst of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains.

|
|
Introductory Note
Although the discussion below is a little dated (as noted at several places as part of editing for html, typographical and grammatical errors on Dec 5/6, 2014), almost all the information below is still perfectly accurate within the level of uncertainty stated in various places. In particular, the discussions of how we know what is going on inside the various Terrestrial planets is as accurate as ever, so this page should be a useful supplement to the material presented in any introductory textbook.
The Structure of the Earth
Students: Refer to the discussion of the Earth's structure in your text before going on.
Of all the planets, only the Earth's structure is well determined. As shown in the diagram below the Earth's interior consists of several layers: the crust, a relatively thin region of low-density silicates, the mantle, a thick region of higher-density iron-rich silicates, and the core, a central region of iron mixed with various impurities. Each of these layers is subdivided into different regions. The crust has continental regions which are made of even lower-density aluminum-rich silicates, and oceanic regions which are much richer in somewhat denser iron-rich silicates. The mantle is divided into an upper mantle within which the iron-rich silicates are gradually compressed from lower-density more open mineral structures, to higher density more compact mineral structures, and a lower mantle, where the mineral structures have been compacted to their densest forms and increase in density as one descends further into the mantle only because of the continually increasing weight compressing them. The core consists of a molten (liquid) outer core primarily consisting of iron but with substantial percentages of materials such as sulfur and silicon which lower its melting temperature, and a solid inner core which is almost certainly a crystalline mixture of iron and nickel similar to iron meteorites.
The layered structure of the Earth, as discussed in some detail above
It should be noted that it is often incorrectly stated in public media that the inner core is solid, while the outer core is liquid, because of the much greater weight compressing the inner core. This is completely wrong. For one thing, if the pressure was responsible for the change, then as you go downward the gradual increase of pressure would produce a gradual change from liquid, to a slushy mixture of liquid and solid, to solid material, which is not
what is observed. The boundary between the two regions is very sudden, as though there is some intrinsic reason unrelated to the pressure which causes the change in state from liquid to solid. Secondly, as discussed below, the pressure in the inner core is only slightly greater than that in the outer core, because regions near the center of a planet, although compressed and held in place by the materials above them, have relatively little weight of their own, being pulled more or less equally in all directions by the outer parts of the planet, and as a result having their weight determined only by their own gravity.
As can be seen in the diagram above the Earth's structure is very accurately known, with the actual depths of each layer (which vary only slightly from one place to another) being known to a fraction of one percent. This accurate determination of the Earth's structure is made possible by the study of seismic waves (earthquake waves) passing through the Earth. There are two types of waves which do so. One, called P-waves, moves about twice as fast as the other, called S-waves, and therefore arrives at a given seismic station before the other; the one that arrives first is called the Primary wave (hence P-wave), and the one that arrives second is called the Secondary wave (hence S-wave).
The velocities of P and S waves at different depths (shown in km)
The diagram above shows the velocities of P and S waves at different depths inside the Earth (it also shows the estimated densities of different parts of the Earth, but we will ignore that for the moment). Note that the P waves always move faster, as previously stated, that the velocities generally increase as you go downward, rapidly near the surface and more slowly in other regions, and that there is a nearly 50% drop in the velocity of P waves (and S wave velocities are not shown at all) in the region labeled as the Outer Core.
How do we know this? By studying how the waves arrive at seismographs scattered around the Earth -- when they arrive, what direction they appear to be coming from, and what intensity (strength) they have (as shown in the image below).
Waves moving through the Earth move at different velocities at different depths. Where the change in velocity is slow the waves bend smoothly; where it is sudden, the waves bend more sharply. (Eugene C. Robertson, USGS)
A more detailed look at the motion of P-waves, showing the paths of many waves emanating from a specific focus (at the top), the travel times (tick marks on the wave paths represent one minute intervals), and the shadow zone formed by the core of the Earth. Waves that should pass through the shadow zone are refracted and concentrated by the core, producing greater intensity in the region opposite the earthquake than would otherwise occur. For Mercury in particular, this effect seems to be very large due to its unusually large core. (S-waves are not shown, as they are absorbed by the core and do not reach the opposite side of the Earth, save for S-waves created at the base of the mantle by P-waves emerging from the core.) (Public domain image from USGS Visual Glossary)
As noted above, the structure of the Earth can be determined in considerable detail from the study of earthquake waves (seismology). Additional information (to be covered in the next iteration of this page) can be obtained from laboratory studies of the behavior of rocks exposed to various pressures and temperatures, and comparisons of those results with seismic studies, from the composition of melt-rock (lava) at various places, and from circumstantial evidence about the structures of other Solar System objects, in the form of meteorites.
Temperatures inside the Earth
Laboratory studies of rock behavior show that in order to mimic the behavior of rocks inside the Earth, laboratory samples must be exposed not only to high pressure (corresponding to the weight of rocks above any point inside the Earth), but also surprisingly high temperatures as shown below.
Temperatures inside the Earth (in red) inferred from comparison of laboratory studies with seismic results, schematic representation (in black) of typical melting temperatures, and (in blue) schematic representation of temperatures of rising plumes of hot mantle material. Where melt-temperatures are lower than actual temperatures (in the outer core), the material is molten (liquid). Where melt-temperatures are higher than actual temperatures (everywhere else), the material is solid. If the melt-temperature is well above the actual temperature (near the surface and in the lower mantle), the rocks are very stiff. If the melt-temperature is close to the actual temperature (in the inner core, at the crust/mantle boundary, and for rising plumes), the rocks are "soft" or "plastic" (easily deformable).
As the above diagram shows, near the surface of the Earth temperatures rise rapidly (as much as 100 Fahrenheit degrees per mile), so that a few tens of miles beneath the surface the temperature is close to the melting temperature of the rocks; and if that rapid temperature rise continued into the core the temperature would exceed the melting and vaporization temperatures of all known materials; but before that happens the temperature increase drops to only a few degrees per mile, so that 1800 miles down, at the base of the mantle, the temperature is only a few thousand degrees higher and well below the melting temperature of the rocks.
The velocity of earthquake waves depends upon the stiffness (rigidity) of the bonds between the molecules that make up the materials inside the Earth. Near the surface the bonds are relatively long and "loose" and the predominant materials (olivine and similar ferromagnesian silicates) have relatively low densities (3.5 to 4.5 tims the density of water, which is much less than the average density of the Earth); but at greater depths the weight of the overlying material pushes the atoms closer together, making the bonds between them shorter and stiffer, thereby (1) increasing the density of the material (since the atoms are closer together they take up less room), (2) increasing the melting temperature (shorter bonds are stiffer and harder to break, which is a requirement for melting the minerals), and (3) increasing seismic wave velocities (shorter, stiffer bonds cause the impulse received by one atom to be transferred to the next atom at a more rapid rate).
Wave velocities and composition changes in the crust and upper mantle
Effects near the crust / mantle boundary
In the diagram above, note the rapid increase in wave velocities near the surface of the Earth (in the crust) caused by the compression of the rocks by the weight of the rocks above them. Close to the surface the difference between actual and melting temperatures is very large (refer to the temperature diagram further above), and the increasing compression is the most significant factor in changing the wave velocity; but at depths of thirty to fifty miles the rapidly increasing temperature gets so close to the slowly increasing melt temperature that the bonds between the atoms, even though shorter than at lesser depths, are "softer" and the rocks, although remaining solid
, become relatively "soft", or less stiff. We see the effects of this in some rocks found at the surface of the Earth in which grains of individual minerals are stretched out into linear structures. The rocks, having been heated to nearly their melting temperature, can "flow", even though in the solid state, in the same way that hot metals can be squeezed between rollers, forming thin sheets (e.g., sheet metal and foils). The reduction in the stiffness of the bonds causes the wave velocities to drop sharply, leading to the terminology shown on the right side of the diagram -- "lithosphere" (rock sphere), for the stiffer, more brittle layers above, and "asthenosphere" (plastic sphere), for the softer, more pliable ("plastic" in that sense, not in the sense of the organic materials sold as plastics in stores) region caused by the small difference between the actual and melt temperatures. The boundary between the crust and mantle is defined by this low-velocity zone, also known as the Mohorovicic Discontinuity (or for short, the Moho).
Effects near the core / mantle boundary
At the core/mantle boundary there is an even larger, more rapid temperature increase -- three to five thousand Fahrenheit degrees in just a few miles distance. This causes large amounts of heat to flow from the core into the lower mantle. Portions of the lower mantle rock are heated to the point where, although still solid, they can slowly flow in a "plastic" way toward the surface (this is discussed below, with respect to the asthenosphere). Hot, solid but "soft" rock is forced upwards through cooler, stiffer rock at rates of 1/2 an inch to 1/2 a foot per year. In the diagram above the blue line represents temperatures in an imaginary "rising plume" of hot soft rock -- cooler than its melt temperature, but well above the temperature of surrounding rocks.
The probable distribution of radionuclides inside the Earth
The reason for the rapid temperature rise in the crust, down to the Mohorovicic Disconuity, is a concentration of radioactive materials near the surface of the Earth when it melted and differentiated, during or very soon after its formation, 4.5 billion years ago. As the short-lived radioactive materials present at that time decayed and disappeared (that is, were transformed into other materials), the heating that caused the Earth to melt also disappeared, and the Earth began to resolidify. The crust cooled rapidly by radiating heat to space, forming a thin low-density slag similar to the highland crust of the Moon, made primarily of silica and aluminosilicates; the deeper regions below, unable to radiate heat directly to space, cooled more slowly and remained hot for a much longer period of time (in fact the core is still extremely hot, partly as a result of the 1800 miles of solid rock insulating it from space, and partly because of heavy radioactive materials such as uranium which were dragged into the core as the heavy material sank to the center of the Earth).
As the Earth cooled minerals and rocks began to form, even in the depths of the mantle. At great depth, because of the large weights compressing the material, only very dense structures could form (as will be discussed in more detail below). Large atoms of uranium can't fit into dense structures unless in a nearly pure form (although pure uranium metal is nearly twenty times denser than water, most uranium ores are much lighter, and nearly pure carnotite, or uranium oxide, is only about the same density as rocks in the upper mantle, which are mostly less than five times the density of water), and even if they could fit into such structures the heat released by radioactive decay would soon melt them again, since when the mantle began to solidify temperatures were still very close to melt temperatures. As a result most of the uranium atoms not dragged into the core were gradually forced toward the surface, where lower density minerals where forming; and most of the uranium in the mantle is believed to lie within a hundred miles of the surface, which means most of the heating due to its radioactive decay is concentrated near the surface. This is believed to be the cause of the rapid temperature rise near the surface. In the top few tens of miles heat slowly flows through the rocks (even at 100 Fahrenheit degrees per mile temperature gradient this heat flow is slow), and is equally slowly replaced by radioactive heating. Below that depth heat flow is much slower, because the heat source is the heat of the core, which is nearly two thousand miles further down, and the temperature rise is much lower.
Before leaving this topic it might be noted that if large amounts of uranium were pulled into the core, the core would still be generating heat through the decay of that material and would still have a very high temperature; and as shown in the temperature graph, although the exact temperatures in the core are very uncertain (because the exact composition is not known, making laboratory simulations of uncertain accuracy), they are certainly much hotter than in the mantle, and there is a bigger, faster rise in temperature at the boundary between the mantle and the core than at the boundary between the crust and the mantle. So although the uranium present in the mantle is probably concentrated near the surface of the planet, much (or even most) of the uranium in the Earth may be in the core.
Mineralogical changes within the mantle
Referring to the diagrams above again, note that once the rate of temperature increase moderates, the greater weight compressing the material again becomes the most important determinant of the wave velocity and wave velocities begin to increase again. In the three or four hundred miles closest to the surface, however, there are two reasons for the increase in wave velocity. The first, which operates throughout the body of the Earth, is the increasing compression of the material, resulting in shorter, stiffer atomic bonds which promote faster exchange of wave impulses from one atom to the next. The other only operates near the surface, and as a result the wave velocity increases more rapidly there than in deeper parts of the mantle, as shown below.
Wave velocity (and density) changes inside the Earth
Note that in every part of the Earth, save for the sudden drop in wave velocity at the core/mantle boundary, wave velocities increase as you go downward; but in the uppermost part of the mantle, save for the drop in velocity at the Mohorovicic Disconuity, wave velocities increase even more rapidly than in other parts of the Earth. The reason for this is that as the weight of rocks compressing the rocks below increases as you go downward, not only can the atoms be pushed closer together, but they can be forced into completely different arrangements which are even denser and stiffer than the rocks above. This is analogous to the difference between graphite, a pure carbon compound formed at low pressures which has large inter-atom distances (particularly in some directions) and is relatively low in density; and diamond, a pure carbon compound formed at high pressures which has small inter-atom distances and is relatively high in density. In a similar way, as olivine and similar minerals are compressed more and more, for a while they remain the same minerals but in a denser state; but once the weight compressing them becomes too great they change to denser structures. This happens at two places inside the mantle. At a depth of about 250 miles olivine and similar minerals change to spinel-like structures (not true spinel, which has a different chemical composition) and other denser, stiffer, higher-melting temperature minerals; and at a depth of about 400 miles those structures change to an even denser mixture of magnesium oxide and perovskite-like structures (not true perovskite, which has a different chemical composition). The overall composition of the three regions is believed to be about the same, but the structure of the minerals is different due to the extreme weight of the layers above compressing the less-dense minerals in the upper layers into the denser structures of the layer lowers.
In that top 400 miles of mantle material the melting temperature, wave velocity and density all increase for the two reasons mentioned above -- the greater and greater weight of material above compressing the minerals and rocks more and more, and the occasional changes from one structure to a denser, stiffer, harder to melt structure. Below that depth, however, the materials are already in the densest possible form for materials of their overall composition, and regardless of how great a weight compresses them they will not change to still denser structures (or at least that is the conclusion drawn from laboratory experiments involving such materials). In the top 400 miles, with two separate factors at work, the density, wave velocity and melting temperatures of the mantle rocks rapidly increase, but below that, with no further structural changes, the rapid increase slows (as shown in the diagrams above).
Application to other planets
Now, what does this tell us about the other planets? After all, we do not have any samples of most of them (we do have samples from the surface of the Moon, and meteorites give us samples of asteroids and in rare cases, of surface rocks from the Moon and Mars), we have no earthquake studies of any value save for the Earth and Moon, and we have no samples of rocks from the interior of any planet (although as will be seen below we do have partial information for Earth mantle rocks as a result of studies of lavas formed from partial melting of rising plumes). So how can we know what is going on inside Venus or Mercury or Mars?
The way we know what is going on is to ask, "What would those planets be like if they were identical in structure to the Earth, save for their smaller size"? Since they all have smaller masses, diameters and gravities than the Earth, the weight compressing various parts of their interior must be less than in similar parts of the Earth, and you would have to go downward a greater distance to get the changes that were discussed above. For Venus, with only 90% of the Earth's gravity, instead of having changes from olivine to spinel at 250 miles depth and from spinel to perovskite at 400 miles depth, such changes would occur at 275 miles and 440 miles depth. In other words, there would be a little bit more of the lower density upper mantle rocks, and even if the mantle on Venus was the same size as the Earth's, there would be a little bit less of the higher density lower mantle rocks. But since Venus is 5% smaller in radius and diameter than the Earth, if its structure were a copy of ours its mantle would be 5% smaller as well, or only 1710 miles thick, instead of 1800 miles.
Combining these results -- a thinner mantle overall and a thicker upper mantle, Venus would have 440 miles of upper mantle material, and 1270 miles of lower mantle material, compared to 400 and 1400 miles respectively, for the Earth; and with more less-dense material and less more-dense material, Venus should be less dense than the Earth if it is otherwise similar in structure.
Comparing the inner planets
With this in mind, let's take a look at the inner planets and see how they compare. Venus has a density only 95% the density of the Earth. Taking everything we know about the Earth's structure into account and compensating for the 10% lower surface gravity, the 20% lower central pressure (if you'd like to see how we know that number, refer to Internal Pressures of the Planets
), the 5% smaller diameter and 20% lower mass, Venus should have a density of 95% of the density of the Earth, if save for differences caused by compressional forces they have identical structures. And that is the density we observe. This does not mean that Venus is a copy of the Earth, but it does mean that if there are any differences in the structure of the two planets, some of those differences must change the density in one direction and others must change them in the other direction, so that the overall density comes out as it does; and to date no structure has been suggested for Venus which is grossly different from that of the Earth, without yielding incorrect density results.
Now as already noted, the core of the Earth is 55% of the radius/diameter of the planet. We can't be certain what Venus is like, but if somewhat similar to the Earth, it is unlikely that the size of the core differs (in comparison to the overall size of the planet) by more than a few percent, so most models of Venus have a core which is close to 55% of the size of the planet, and a mantle which is close to 45% of the size of the planet (albeit with lower densities throughout and a thicker upper mantle, compared to the Earth). When, at some distant time in the future, we have detailed studies of the internal structure of Venus we may find that these numbers are slightly "off", but any large discrepancy is considered very unlikely.
So what about Mercury and Mars? They have much lower masses than either the Earth or Venus, much smaller sizes and much lower gravities. Mars is only a little over half the size of the Earth (smaller than our core and far less massive, as will be discussed below), so its mantle would be only a little over 900 miles deep if it were a smaller version of the Earth; but since its gravity is over 2 1/2 times less than ours, the 400 mile deep boundary between the upper and lower mantle on the Earth would be over a thousand miles deep on Mars. In other words, if merely a smaller copy of the Earth, Mars would have no lower mantle; the rocks found throughout the mantle would be like those in the upper mantle of the Earth. Obviously, this means (referring to the graph of density inside the Earth, above) that Mars should be even less dense than Venus; and Mercury, which is smaller yet, should be still less dense.
Now there are reasons for suspecting that Mars and Mercury might not be as similar to the Earth as Venus; but ignoring those for the moment, let's suppose that the above arguments are correct. How low might the density of Mars and Mercury be? Different calculations (again, refer to the Internal Pressures of the Planets for more details) give different results, but we would expect overall densities in the range of 80 to 85% the density of the Earth for Mars and a little less than that for Mercury, if they are smaller versions of the Earth. But unlike Venus, for which the calculated and observed densities are the same (within the errors produced by various assumptions necessary to the calculations), Mercury is much denser than we would expect, and Mars much less dense than we would expect. In other words, neither Mars nor Mercury can be merely a smaller version of the Earth. Still, they are both relatively dense compared to rocks found at the surface of the Earth and Moon, so they must be made of heavy materials that are in some way similar to the interior of the Earth; so how can we explain this odd result?
Review of the Earth's Structure (as discussed above)
We have already discussed the internal structure of the Earth in detail, as far as the mantle is concerned. Near the surface, the upper mantle consists of (relatively) low density minerals such as olivine, further down the increasing compression of the rocks changes the olivine to higher-density spinel-like structures, and still further down to still higher-density perovskite-like/magnesium oxide mixtures; but according to laboratory experiments, no further change in the structure can be accomplished at any pressure which might conceivably exist inside the Earth; and most importantly, if the entire Earth consisted of such deep-mantle rocks, even though they would gradually become denser and denser as you go deeper and deeper into the Earth, the overall density of the Earth would be nearly 20% lower than observed, if that were all the Earth were made of.
But that isn't all the Earth is made of, for the structures discussed so far only apply to the rocks in the mantle, and the core of the Earth, as it turns out, is made of much denser materials. The nature of those materials has been a matter of controversy for the best part of a century and even now there is considerable uncertainty about some of the details, but we are virtually certain that the central (inner) core is a crystalline structure consisting of pure or nearly pure nickel-iron, similar to the iron meteorites which fall on the Earth from outer space.
They Came From Space
(Students: refer to your text and the website discussion of meteorites
as background for this)
Each day the Earth runs into hundreds of tons of small bits of debris left over from the formation of the Solar System, or "recently" lost by other objects, primarily by collisions. Most of this debris is light, fluffy stuff which is vaporized by the heat of its passage (at tens of thousands of miles per hour) through our atmosphere; but a small percentage consists of denser, tougher stuff which if in the right size range can reach the surface, and in a very small minority of cases be picked up and studied in detail. These objects are called meteorites (the -ite ending meaning a rock, and the meteor- prefix meaning that it fell out of the sky).
The vast majority of meteorites have been established, by a number of lines of evidence, as being pieces left over from the formation of the asteroid belt, or recently broken off of asteroids. There are, as already noted, a very small minority that are pieces blasted off the surface of the Moon or Mars, but although these are of great interest in other circumstances, they are of little importance at this point in our discussion. It is the asteroidal pieces that tell us the most about the inside of the Earth and other "Terrestrial" objects, which includes, as it turns out, at least a large subset of the asteroids which are the parent bodies of the meteorites which were broken off of other objects.
Some of the asteroidal meteorites are "primitive" objects which, based on their chemical and physical characteristics, have never been exposed to very high temperatures, so the minerals in them are more or less as they were when they first formed, 4.5 billion years ago, during the formation of the Solar System. Most of the meteorites, however, have physical and chemical properties which imply that they were broken off of objects which at some point in their history melted and differentiated just as the Earth did, so that heavy materials sank to the center and lighter materials rose to the top. The vast majority (about 90%) of these "differentiated" meteorites consist of rocky materials very similar to those believed to exist in the uppermost part of the Earth's mantle (the olivine rich portion), suggesting that they came from objects that developed a rocky mantle like the Earth, but like Mars and Mercury were so small that they did not develop the denser mineral structures found at greater depths inside the Earth. In fact one of the original reasons for suspecting this structure for the outer portion of the Earth was the example set by these rocky meteorites, or "stones".
There is another type of meteorite, however, which is relatively rare (less than 10% of meteorites in situations where selection effects are minor) -- the "irons". These dense metallic meteorites are made of interlocking crystalline structures (see Widmanstatten structures in your text) caused by melt-materials with greater or lesser percentages of nickel crystallizing out of the molten interior of the bodies they were derived from. Most of the material is iron (close to 90%), but variations in the nickel content cause differences in the reaction of the crystals to etching by acids, which make the interlocking structures stand out when properly treated.
To create such structures requires a molten mixture of iron and nickel slowly cooling over long periods of time. If such a mixture is cooled on times short compared to a human lifetime, the crystalline structures still form, but are microscopic in size. The structures observed in iron meteorites are easily visible to the eye, and require cooling over very long periods of time, probably in excess of a million years; and the only way we can imagine this happening is if a fairly large body (hundreds of miles in diameter) melted, allowing heavy stuff to sink to the middle and light stuff to float to the top, then cooled and solidified. But this is exactly what we think the Earth must have done, and presumably some of the larger asteroids must have done the same in order for pieces of those objects to include such irons; and if so, every Terrestrial object that was more than a few hundred miles in size during the melting episode in the early history of the Solar System must have developed a rocky mantle and an iron core. The stones are therefore interpreted as pieces from the outside of such objects, and the irons as pieces from the inside.
Application of Information From Meteorite Studies to the Earth
But if that's the case, then the Earth and the other Terrestrial planets must have rocky mantles and iron cores; most likely, if they are solid, crystalline iron cores such as those in the iron meteorites. And the density of those cores would be much higher than that of the mantles, because the materials in the core are intrinsically about twice as dense as the rocky materials in the mantle, and with the entire weight of the planet compressing a core, its contents must be compressed in size and increased in density at least as much as the mantle. So when a calculation of the structure of a planet such as the Earth, based on a strictly rocky structure (as discussed above) gives a density which is too low to explain the overall density of the planet, the solution to the problem must be that the core, consisting primarily of much denser nickel-iron mixtures/crystals, must provide the extra mass required.
In the case of the Earth, of course, we know exactly how big the core is, and we have a very good idea of how much mass (and deficit of mass, compared to the average density of the Earth) the mantle has. The mantle of the Earth, despite being about 85% of its volume (100% minus the 15% corresponding to cubing the radius of the core), has a mass less than 70% of the mass of the Earth. The deficit of mass must be made up by the core, which despite being only 15% of the volume, must have more than 30% of the Earth's mass -- and as a result, twice as much mass as Mars and Mercury put together. This means that whatever the core is made of can't be rare stuff like gadolinium or ruthenium, but must be common stuff like iron (one of the most abundant metals in the Universe), which agrees with the evidence from meteorites, and allows us to more or less confidently say that the core must be "just like" the iron meteorites.
Of course, before it was possible to achieve pressures in the laboratory equal to those in the center of the Earth, it was conceivable that the higher than expected density of the Earth might be explained by yet another change in the structure of the materials, such as the olivine - spinel - perovskite changes in the mantle; but now that we can achieve such pressures, we know that no further such changes are likely to occur in the mantle, or to explain the Earth's high density. And if we test nickel-iron mixtures, we find that at the pressures which must exist in the core of the Earth, they have just the right density (and other properties such as wave velocities) to explain the density and structure of the Earth.
However, we don't believe that the entire core of the Earth is a crystalline mixture of nickel-iron similar to the iron meteorites. As shown in the temperature diagram and in the wave-velocity diagram, the outer core of the Earth must be a liquid, or given the materials and temperatures involved, a molten material (molten meaning a liquid form of a normally solid material that requires very high temperatures to melt); and the molten outer core of the Earth cannot be made of exactly the same materials as the solid inner core, because the temperature of the Earth must be higher the further down you go (heat only goes from hot places to cold places, and since it comes from inside the Earth and escapes at the surface, the temperature of necessity must increase all the way down, regardless of any details that we wouldn't want to consider in an introductory discussion and although there is a lot covered here, so it may seem complicated, this is actually a very simple discussion compared to what a student majoring in astronomy, geology, planetary geology or geophysics would encounter).
Now if the inner core of the Earth must be hotter than the outer core (at least 12000 Fahrenheit degrees, which is hotter than the surface of the Sun, based on the best current estimates), and despite that the inner core is solid, there must be some reason for that. One possible reason is that the greater weight compressing the inner core might raise the melting temperature; but this is unlikely to be the case. First, if that were true the boundary between the inner and outer core would be a broad transition zone, with molten material further out, partially molten and partially solid material further down, and more nearly completely solid material still further down; and the way in which earthquake waves penetrate the inner/outer core boundary tells us that there is a relatively sudden transition from liquid to solid. Second, as you near the center of the Earth, the weight of the materials drops to zero (see the afore-mentioned page on Internal Pressures of the Planets for a detailed discussion), because they are pulled equally hard in all directions by the various parts of the Earth all around them, so those forces cancel out, and the change in pressure is surprisingly low in the central regions of the Earth.
The internal pressures in a uniform planet
Near the surface (on the right) the weight compressing the interior rapidly increases as you go down; but near the center (on the left) the weight hardly changes, because as you near the center the weight of the materials drops to nearly zero (even though their mass is the same as if they were at the surface of the planet).
Since the outer/inner core boundary is sharp and the pressure on either side of the boundary is nearly equal (given the nearly flat curve for pressure near the center, as shown just above), there is only one way to explain the solid nature of the inner core and the molten nature of the outer core: the inner core must be made of a material that has a higher melting temperature. And the easiest (and based on laboratory experiments and theoretical calculations, the best) way to explain this is if the inner core is a crystalline structure consisting of nearly pure nickel-iron, as for the iron meteorites, while the outer core is a mixture of similar materials with additional materials that depress the melting temperature in the same way that salt depresses the melting temperature of ice (pure ice melting at 32 Fahrenheit, and very salty ice melting at 0 Fahrenheit, so that at intermediate temperatures pure ice can exist as a solid floating in a salty mixture of water and other materials, as in polar seas). The most likely candidates for the impurities that depress the melting temperature are silicon and oxygen, because those are the basic building blocks out of which the silicate materials in the mantle are formed, and lesser amounts of other materials. Different investigators favor different ratios of impurities to nickel-iron, leading to estimates of 10 to 30% other materials and 70 to 90% nickel-iron in the molten outer core (it is the uncertainty of these values that causes the large uncertainty in the temperature of the core); but no matter what the ratio is, the large amount of dense materials such as iron in the core give it the required extra mass to make up for the deficit of mass in the mantle, compared to the overall density of the Earth.
Volcanic eruptions and the composition of the mantle
One additional topic which should be briefly mentioned is that it is possible to directly test certain aspects of the theory that the outer portions of the Earth are at least vaguely similar to the stony meteorites. As already mentioned, the heat difference at the core/mantle boundary causes hot, relatively soft rock to rise toward the surface. As they approach the surface, the rocks cool, because at their (very slow) upward rate of motion it takes a long time for them to cover the 1800 miles from the lower mantle to the surface; but they always remain close to their melt temperatures (in the temperature graph at the top of this page, the black line represents an estimate of melt temperatures at various depths, and the blue line represents an estimate of rising plume temperatures), so when they reach the region near the Mohorovicic Discontinuity where the difference between normal and melt temperatures is small, the rising rocks are even closer to melt temperature, and lower-melting-temperature minerals within the rising plumes often do melt, and force their way to the surface. This is the source of most lavas expelled at the surface of the Earth. In some places, such as the west coast of the Americas, where continental plates ride over and push oceanic plates into the deep interior, friction between the plates can heat the downward-moving rock, partially melting it and causing volcanic eruptions. The rocks that melt in this way have very little gas or liquid trapped inside them, and the lavas are stiff and tend to produce explosive eruptions. At most places on Earth, however, fresh lava is produced from the melting of upward-moving mantle rock, and this lava always contains large amounts of dissolved gases, which make it very fluid and cause "fountain"-type eruptions such as those in the Hawaiian islands and Iceland (both being regions located above rising plumes of hotter than usual mantle rocks). The composition of these lavas and their gases provide important clues to the composition of the source material, which is of course mantle rock, and the results strongly suggest that mantle rock is indeed very similar in composition to the stony meteorites.
Summary, and Application to the Other Terrestrial Planets
For an object like the Earth (or Venus, since it appears to be similar to the Earth, as already discussed) we have an outer rocky mantle consisting of various forms of ferromagnesian silicates, depending upon the pressure compressing the material at various depths, and an overall density 20 to 25% less than the actual density of the Earth; and an inner primarily metallic core consisting mostly of iron, but with lesser amounts of nickel and in the outer core additional materials, which has an overall density two to three times that of the Earth. The much greater excess of density in the core, compared to the small deficit of density in the mantle, may be surprising, but keep in mind that the mantle has nearly six times the volume of the core, so that every 1% deficit in the mantle requires a more than 6% excess in the core.
At this point, we can essay a guess as to why Mars is about 20% less dense than expected and Mercury nearly 25% denser than expected if they were merely smaller copies of the Earth. Namely, Mercury's dense metallic core must be a much larger proportion of its volume and mass, and Mars' core must be a much smaller proportion of its volume and mass, than for the Earth. Whereas the Earth has a core which is 55% of its overall radius and Venus must have a core fairly close to that (certainly no less than 50% or more than 60% of the overall radius), Mars may well have a core less than a third the size of the planet, and Mercury's core is probably 70 to 80% of the size of the planet. So we can summarize by saying that the Earth and Venus have "average" size cores, Mars a "small" core, and Mercury a "large" core; but in saying that, keep in mind that the core of the Earth is bigger than all of Mars, and more than twice as heavy as Mars and Mercury put together; so although Mercury's core is large in comparison to the overall size of that planet, it is still very small in comparison to the core of the Earth.
These numbers are of course uncertain. We cannot know, at present, the exact nature of the rocks in the mantle of either Mercury or Mars (or for that matter, Venus), and if they are significantly different from the rocks in our mantle, that might affect the mass deficit of the mantle to a significant extent, and change the size the core of the planet has to be to make things come out right. For Mars the chances that the mantle rocks are significantly different from those in the asteroids (the source of the stony meteorties) or the Earth are relatively small; but for Mercury, we might well find (when we can finally find out anything about the structure of Mercury from direct observation) that the mantle is different from ours in various ways, so the actual size of the core is a bit uncertain (although most likely, closer to the description here than not).
 Note added in December 2014 during editing of this page for typographical and grammatical errors
: Thanks to the study of Mercury by the MESSENGER spacecraft in the years since this page was last updated, we now know far more about the structure and geological history of Mercury than implied in the previous paragraph; so a (separate) discussion of the structure of Mercury will add considerable detail to the discussion here. However, the overall results discussed above are, within the uncertainties stated, still correct. Similar improvements in the detailed structure of Mars have also been obtained by gravimetric studies of the planet by spacecraft orbiting the planet; and some of those details are already included in the page about the structure of Mars. However, no improvement has been made in our knowledge of Venus, because there have been no spacecraft sent to the planet in recent years.
Internal structures of the Terrestrial planets. For Venus the core must be similar to that of the Earth in comparison to its size, but for Mercury the core is relatively large in comparison to its size, and for Mars the core is either relatively small (as shown here), or made of lighter than usual materials (in particular, it appears that Mars' molten outer core may have considerably more sulfur than the Earth's). Note that although Mercury's core is large in comparison to the size of that planet, it is not large compared to the Earth's core. The Earth's core is larger than Mars and more than twice as massive as Mars and Mercury combined. (Image based on NASA image of some age; as a result, more recent models of Mars and Mercury show more detail)

இந்தத் தட்டுகள் இறுக்கமான அமைப்புகளைக் கொண்டது மேலும் அவை ஒன்றோடொன்று நகர்ந்து மூன்று வகைத் தட்டுளாக எல்லைகளை உருவாக்குகின்றன: அவை முறையே குறுகும் எல்லைகள், இரண்டு தட்டுகள் ஒன்றை நோக்கி மற்றொன்று நகர்தல், விலகும் எல்லைகள், பலகைகள் ஒன்றைவிட்டு மற்றொன்று விலகுதல் மற்றும் உருமாறும் எல்லைகள், இரண்டு தட்டுகள் ஒன்றோடு ஒன்று பக்கவாட்டில் உரசிச் செல்வது என்பனவாம். இந்த செயல்களால் தட்டுகளின் எல்லைகளில் பூகம்பம், எரிமலைகள், மலைகள் உருவாக்கம் மற்றும் ஆழ் கடலடிப் படுபள்ளங்கள் உருவாகுகின்றன.

நிலப்பலகைத் தட்டுகள் அசுதனோ அடுக்கின் மேல் நகர்ந்துச் செல்கின்றது, அதாவது இவ்வடுக்கின் பாகு நிலையிலுள்ள ஆனால் திடமான மேல் மூடகத்தின் பகுதிகள் நிலப்பலகைத் தட்டுகளுடன் நகரக்கூடிய தன்மையைக் கொண்டதாய் உள்ளது, மேலும் இவற்றின் இயக்கம் புவியின் மூடகத்தின் உள்ளே ஏற்படும் இயக்க மாதிரிகளை சார்ந்தே அமைகின்றது.

These arms contain end-to-end systems and also create arms with three kinds of arms: the arms that cross the way, the two arms to one to the other, the arms to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other. Those who are in the midst of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains.

These arms contain end-to-end systems and also create arms with three kinds of arms: the arms that cross the way, the two arms to one to the other, the arms to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other to the other.

Those who are in the midst of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains.

+ The main brakes of the brake are 250px, with the name size of 106m2 of the brake brake brake brake brake brake brake brake brake brake brake brake brake brake brake brake brake.

+ புவியின் முக்கிய தட்டுகள் 250pxதட்டின் பெயர்பரப்பளவு106கி.மீ.² ஆப்பிரிக்க தட்டுசோமாலியத் தட்டு உட்பட, இது தற்போது ஆப்பிரிக்க தட்டிலிருந்து தோன்றும் செயலில் உள்ளது.

+ புவியின் முக்கிய தட்டுகள் 250pxதட்டின் பெயர்பரப்பளவு106கி.மீ.² ஆப்பிரிக்க தட்டுசோமாலியத் தட்டு உட்பட, இது தற்போது ஆப்பிரிக்க தட்டிலிருந்து தோன்றும் செயலில் உள்ளது.

+ The main brakes of the brake are 250px, with the name size of 106m2 of the brake brake brake brake brake brake brake brake brake brake brake brake brake brake brake brake brake.

+ The main brakes of the brake are 250px, with the name size of 106m2 of the brake brake brake brake brake brake brake brake brake brake brake brake brake brake brake brake brake.

+ The main drives of the picture are 250pxThe name size of the picture is 106m2

250pxதட்டின்

பெயர்பரப்பளவு106கி

Question: what is the size of the main drives

+ The main drives of the picture are 250pxThe name size of the picture is 106m2

Question: how manypx are the main drives in the picture

how manypx are the main drives in the picture

Question: how many m2 drives are there in the picture

how many m2 drives are there in the picture

Question: 250px is the size of what part of the computer

250px is the size of what part of the computer

Question: what is the number of drives in the picture

what is the number of drives in the picture

+ The main drives of the picture are 250pxThe name size of the picture is 106m2

+ புவியின் முக்கிய தட்டுகள் 250pxதட்டின் பெயர்பரப்பளவு106கி.மீ.²

+ புவியின் முக்கிய தட்டுகள் 250pxதட்டின் பெயர்பரப்பளவு106கி.மீ.²

+ The main drives of the picture are 250pxThe name size of the picture is 106m2

+ The main drives of the picture are 250pxThe name size of the picture is 106m2

It is a shadow of the shadow, and it is a shadow of the shadow of the shadow.

See:78.0 Antarctic Gate60.9 Icelandic Gate47.2 North American Gate67.8 North American Gate75.9 South American Gate43.6 Baseball Gate103.3 is the upper area of the very long-distance gate, which is called the Lithuanian Gate, and is divided into the stationary gate.

தட்டுசோமாலியத்

தட்டிலிருந்து

"பார்க்க:78.0

அண்டார்க்டிக்

ஆத்திரேலியத்

பிரிந்திருக்கின்றது

Question: what is the upper area of the long distance gate called

It is a shadow of the shadow, and it is a shadow of the shadow of the shadow.

See:78.0 Antarctic Gate60.9 Icelandic Gate47.2 North American Gate67.8 North American Gate75.9 South American Gate43.6 Baseball Gate103.3 is the upper area of the very long-distance gate, which is called the Lithuanian Gate, and is divided into the stationary gate.

what is the upper area of the long distance gate called

Question: what is the difference between the stationary gate and the latinian gate

what is the difference between the stationary gate and the latinian gate

Question: what is the upper gate of the latinian gate called

what is the upper gate of the latinian gate called

Question: what is the difference between the latin and indian gate

what is the difference between the latin and indian gate

Question: what is the difference between the two types of gate

what is the difference between the two types of gate

Question: what is the difference between the north american and south american gate

"ஆப்பிரிக்க தட்டுசோமாலியத் தட்டு உட்பட , இது தற்போது ஆப்பிரிக்க தட்டிலிருந்து தோன்றும் செயலில் உள்ளது

what is the difference between the north american and south american gate

Question: what number is the antarctic gate

"பார்க்க:78.0

It is a shadow of the shadow , and it is a shadow of the shadow of the shadow .

See:78.0 Antarctic Gate60.9 Icelandic Gate47.2 North American Gate67.8 North American Gate75.9 South American Gate43.6 Baseball Gate103.3 is the upper area of the very long - distance gate , which is called the Lithuanian Gate , and is divided into the stationary gate .

ஆப்பிரிக்க தட்டுசோமாலியத் தட்டு உட்பட, இது தற்போது ஆப்பிரிக்க தட்டிலிருந்து தோன்றும் செயலில் உள்ளது. பார்க்க:78.0 அண்டார்க்டிக் தட்டு60.9 ஆத்திரேலியத் தட்டு47.2 யுரேசியத் தட்டு67.8 வட அமெரிக்கத் தட்டுத் தட்டு75.9 தென் அமெரிக்கத் தட்டு43.6 பசுபிக் தட்டு103.3 மிகவும் இறுக்கமான புவியின் மேல் பரப்பு, லித்தோ அடுக்கு எனப்படும் இது, நிலப்பலகைத் தட்டுகளாக உடைந்து பிரிந்திருக்கின்றது.

ஆப்பிரிக்க தட்டுசோமாலியத் தட்டு உட்பட, இது தற்போது ஆப்பிரிக்க தட்டிலிருந்து தோன்றும் செயலில் உள்ளது.

பார்க்க:78.0 அண்டார்க்டிக் தட்டு60.9 ஆத்திரேலியத் தட்டு47.2 யுரேசியத் தட்டு67.8 வட அமெரிக்கத் தட்டுத் தட்டு75.9 தென் அமெரிக்கத் தட்டு43.6 பசுபிக் தட்டு103.3 மிகவும் இறுக்கமான புவியின் மேல் பரப்பு, லித்தோ அடுக்கு எனப்படும் இது, நிலப்பலகைத் தட்டுகளாக உடைந்து பிரிந்திருக்கின்றது.

It is a shadow of the shadow, and it is a shadow of the shadow of the shadow. See:78.0 Antarctic Gate60.9 Icelandic Gate47.2 North American Gate67.8 North American Gate75.9 South American Gate43.6 Baseball Gate103.3 is the upper area of the very long-distance gate, which is called the Lithuanian Gate, and is divided into the stationary gate.

It is a shadow of the shadow, and it is a shadow of the shadow of the shadow.

See:78.0 Antarctic Gate60.9 Icelandic Gate47.2 North American Gate67.8 North American Gate75.9 South American Gate43.6 Baseball Gate103.3 is the upper area of the very long-distance gate, which is called the Lithuanian Gate, and is divided into the stationary gate.

If the stainless wire is inserted in the production of the wire, the wire wire in the wire is inserted. Similarly, the wire wire in the wire will create the wire wire in the wire out of the wire materials. Though these two acts are constantly inserted in the wire with the wire in the wire under the wire.

மேற்பரப்பில்

உள்ளிழுத்துக்

கொள்ளப்படுகின்றது

செயல்களாலும்

தொடர்ச்சியாக

ஈடுபடுகின்றது

I was wondering about the direction in which the pacific floor has been moving? in what direction has it been moving ? and what suggests this?
The floor of the Pacific Ocean is divided into several plates. The largest one, the Pacific Plate is moving north west relative to the plate that holds North America, and relative to hot spots coming up through the mantle from below the plates (they generate islands like Hawaii). On the surface of the earth, nothing can move along a straight line, instead the plates rotate around a point on the surface. The pacific plate rotates around a point south of Australia. Around Hawaii, the plate is moving at about 7 cm/year, or about as fast as finger mails grow.
The evidence for this motion is pretty convincing:
earthquakes: earthquakes occur on the boundaries of the plates as they rub past each other. The motion observed during these earthquakes agrees well with the expected motion.
absolute measurements: Thanks to the Global Positioning System navigation system, we can now measure the location of any point on the earth to within a few cm. The observed motions agree with expected plate motions.
plate boundaries: where two plates meet there can be three types of boundaries: transform faults where the plates slide past each other (like the San Andreas fault); spreading centers where two plates are moving away from each other (like the Juan de Fuca spreading center off the Pacific NW and the mid-Atlantic Ridge; and subduction zones where one plate dives into the earth under another plate (Aleutian Islands, Japan). All the observed boundariies should agree with the expected motions - and they do.
magnetism: new rock is added to the the plates at spreading centers as they split apart. As this lave cools, it becomes magnetized, much like a magnetic tape does in your tape recoder. When the magnetic field of the earth changes, this change is recorded in the rocks. We can read this record by sensing the changes in the magnetic field from ships, and we see stripes of different magnetism parallel to the spreading centers, as expected if the plates are splitting apart there.
sediments: in the deep ocean there is a very slow but continuous rain of mud that slowly settles to the ocean bottom and forms layers of sediment. Since the ocean floor is youngest near the spreading centers, we would expect very little sediment there, and the layers should get thicker the farther you get from a spreading center. This is observed, and the age of the oldest (deepest) fossils in the sediment obtained by drilling in the ocean floor gives us an idea of the age of the ocean floor at that spot. Studies show that the ocean floor gets older as you get farther away from spreading centers, and that the OLDEST ocean floor on the earth today is only about 200 million years old. That may sound very old, but the oldest FOSSILS are over 3 BILLION years old.
There is more evidence, and you can read about it in a good geology text book.
Dr. Fred Duennebier, Professor
Department of Geology and Geophysics
University of Hawaii, Honolulu, HI 96822

Question: what type of wire is used in production of the wire

If the stainless wire is inserted in the production of the wire, the wire wire in the wire is inserted. Similarly, the wire wire in the wire will create the wire wire in the wire out of the wire materials. Though these two acts are constantly inserted in the wire with the wire in the wire under the wire.

what type of wire is used in production of the wire

Question: what type of wire is used in the production of the wire

what type of wire is used in the production of the wire

Question: what happens if stainless wire is inserted in production of the wire

கொள்ளப்படுகின்றது

what happens if stainless wire is inserted in production of the wire

Question: what is inserted in the production of the wire

what is inserted in the production of the wire

Question: where does the wire wire come from

பொருட்கள் வெளியேறி நடுப் பெருங்கடல்

Question: what is inserted in the production of stainless wire

what is inserted in the production of stainless wire

Question: what is inserted in the stainless wire to create the wire in the wire

what is inserted in the stainless wire to create the wire in the wire

If the stainless wire is inserted in the production of the wire , the wire wire in the wire is inserted . Similarly , the wire wire in the wire will create the wire wire in the wire out of the wire materials . Though these two acts are constantly inserted in the wire with the wire in the wire under the wire .

நிலப்பலகை தட்டுகள் கோளின் மேற்பரப்பில் நகர்வதால், குறுகும் எல்லைகளில் உள்ள பெருங்கடல் தரைகள் உள்ளிழுத்துக் கொள்ளப்படுகின்றது. அதே சமயம், தட்டுகளில் விலகு எல்லைகளால் மூடகப் பொருட்கள் வெளியேறி நடுப் பெருங்கடல் அகழிகள் உருவாகின்றன. இந்த இரு செயல்களாலும் பெருங்கடல் கீழ் புவியின் மேலோடு தொடர்ச்சியாக மூடகத்தோடு மீள் சுழற்சியில் ஈடுபடுகின்றது.

நிலப்பலகை தட்டுகள் கோளின் மேற்பரப்பில் நகர்வதால், குறுகும் எல்லைகளில் உள்ள பெருங்கடல் தரைகள் உள்ளிழுத்துக் கொள்ளப்படுகின்றது. அதே சமயம், தட்டுகளில் விலகு எல்லைகளால் மூடகப் பொருட்கள் வெளியேறி நடுப் பெருங்கடல் அகழிகள் உருவாகின்றன. இந்த இரு செயல்களாலும் பெருங்கடல் கீழ் புவியின் மேலோடு தொடர்ச்சியாக மூடகத்தோடு மீள் சுழற்சியில் ஈடுபடுகின்றது.

If the stainless wire is inserted in the production of the wire, the wire wire in the wire is inserted. Similarly, the wire wire in the wire will create the wire wire in the wire out of the wire materials. Though these two acts are constantly inserted in the wire with the wire in the wire under the wire.

If the stainless wire is inserted in the production of the wire, the wire wire in the wire is inserted. Similarly, the wire wire in the wire will create the wire wire in the wire out of the wire materials. Though these two acts are constantly inserted in the wire with the wire in the wire under the wire.

The other main armies, the Indian army, the Arab army, the Crimea army, the South American army, and the southern Atlantic army, are the army army in the southern Atlantic.

அமெரிக்காவின்

பெருங்கடலில்

Question: what is the army army of the southern atlantic

The other main armies, the Indian army, the Arab army, the Crimea army, the South American army, and the southern Atlantic army, are the army army in the southern Atlantic.

what is the army army of the southern atlantic

Question: where are the main armies of the indian army located

where are the main armies of the indian army located

Question: what is the main army in the southern atlantic

இந்தியத் தட்டு

what is the main army in the southern atlantic

Question: what army is in the southern atlantic

தென் அமெரிக்காவின்

Question: what is the main army army in the southern atlantic

what is the main army army in the southern atlantic

The other main armies , the Indian army , the Arab army , the Crimea army , the South American army , and the southern Atlantic army , are the army army in the southern Atlantic .

மற்ற முக்கிய தட்டுகள், இந்தியத் தட்டு, அரேபியத் தட்டு, கரீபியத் தட்டு, தென் அமெரிக்காவின் வடகரையில் இருக்கும் நாசுகாத் தட்டு மற்றும் தெற்கு அட்லாண்டிக் பெருங்கடலில் உள்ள சுகோசியத் தட்டு என்பனவாம்.

மற்ற முக்கிய தட்டுகள், இந்தியத் தட்டு, அரேபியத் தட்டு, கரீபியத் தட்டு, தென் அமெரிக்காவின் வடகரையில் இருக்கும் நாசுகாத் தட்டு மற்றும் தெற்கு அட்லாண்டிக் பெருங்கடலில் உள்ள சுகோசியத் தட்டு என்பனவாம்.

The other main armies, the Indian army, the Arab army, the Crimea army, the South American army, and the southern Atlantic army, are the army army in the southern Atlantic.

The other main armies, the Indian army, the Arab army, the Crimea army, the South American army, and the southern Atlantic army, are the army army in the southern Atlantic.

It will be very fast by the crossing, where the crossing crossing is 75 meters per year and the crossing crossing crossing crossing is 52-69 meters per year.

The city is very mild in the western part of the city, which is 21 meters a year away from the city.

கொண்டிருப்பவை

"மறுபுறத்தில்

வருடத்திற்கு

Question: how far away is the city from the city

It will be very fast by the crossing, where the crossing crossing is 75 meters per year and the crossing crossing crossing crossing is 52-69 meters per year.

The city is very mild in the western part of the city, which is 21 meters a year away from the city.

Question: how fast is the crossing crossing crossing

how fast is the crossing crossing crossing

Question: how far is the crossing crossing from the city

75 மீட்டரும்

how far is the crossing crossing from the city

Question: how many meters per year is the crossing crossing

how many meters per year is the crossing crossing

Question: how fast is the crossing crossing

வருடத்தில் 75 மீட்டரும்

Question: what part of the city is mild

It will be very fast by the crossing , where the crossing crossing is 75 meters per year and the crossing crossing crossing crossing is 52 - 69 meters per year .

The city is very mild in the western part of the city , which is 21 meters a year away from the city .

பெருங்கடல் தட்டுகளிளே மிகவும் வேகமாக நகர்ந்து கொண்டிருப்பவை, இதில் கோகோசுத் தட்டு வருடத்தில் 75 மீட்டரும் மற்றும் பசிபிக் பெருங்கடல் தட்டு ஆண்டிற்கு 52–69 மி.மீ. வரையிலும் நகர்கின்றன. மறுபுறத்தில் மிகவும் மெதுவாக நகரும் தட்டுகளில் யுரேசியன் தட்டு ஆகும், இது வருடத்திற்கு 21 மீட்டர் தூரம் நகர்கின்றது.

பெருங்கடல் தட்டுகளிளே மிகவும் வேகமாக நகர்ந்து கொண்டிருப்பவை, இதில் கோகோசுத் தட்டு வருடத்தில் 75 மீட்டரும் மற்றும் பசிபிக் பெருங்கடல் தட்டு ஆண்டிற்கு 52–69 மி.மீ. வரையிலும் நகர்கின்றன.

மறுபுறத்தில் மிகவும் மெதுவாக நகரும் தட்டுகளில் யுரேசியன் தட்டு ஆகும், இது வருடத்திற்கு 21 மீட்டர் தூரம் நகர்கின்றது.

It will be very fast by the crossing, where the crossing crossing is 75 meters per year and the crossing crossing crossing crossing is 52-69 meters per year. The city is very mild in the western part of the city, which is 21 meters a year away from the city.

It will be very fast by the crossing, where the crossing crossing is 75 meters per year and the crossing crossing crossing crossing is 52-69 meters per year.

The city is very mild in the western part of the city, which is 21 meters a year away from the city.

The place of the earth is very different from the place.

வேறுபட்டுள்ளது

The greenhouse effect is a naturally occurring process that aids in heating the Earth's surface and atmosphere. It results from the fact that certain atmospheric gases, such as carbon dioxide, water vapor, and methane, are able to change the energy balance of the planet by absorbing longwave radiation emitted from the Earth's surface. Without the greenhouse effect life on this planet would probably not exist as the average temperature of the Earth would be a chilly -18° Celsius, rather than the present 15° Celsius.
As energy from the Sun
passes through the atmosphere a number of things take
place (see Figure
7h-1). A portion of the energy (26% globally)
is reflected or scattered back
to space by clouds and other atmospheric particles. About
19% of the energy available is absorbed by clouds, gases
(like ozone),
and particles in the atmosphere. Of the remaining 55%
of the solar energy passing through the Earth's atmosphere,
4% is reflected from the surface back to space. On average,
about 51% of the Sun's radiation reaches the surface.
This energy is then used in a number of processes, including
the heating of the ground surface; the melting of ice
and snow and the evaporation of water; and plant photosynthesis.
The heating of the ground by sunlight causes the Earth's surface to become a radiator of energy in the longwave band (sometimes called infrared radiation). This emission of energy is generally directed to space (see Figure 7h-2). However, only a small portion of this energy actually makes it back to space. The majority of the outgoing infrared radiation is absorbed by the greenhouse gases (see Figure 7h-3 below).
Figure 7h-3: Annual (1987) quantity of outgoing longwave radiation absorbed in the atmosphere.
(Image created by the CoVis Greenhouse Effect Visualizer).
Absorption of longwave radiation by the atmosphere causes additional heat energy to be added to the Earth's atmospheric system. The now warmer atmospheric greenhouse gas molecules begin radiating longwave energy in all directions. Over 90% of this emission of longwave energy is directed back to the Earth's surface where it once again is absorbed by the surface. The heating of the ground by the longwave radiation causes the ground surface to once again radiate, repeating the cycle described above, again and again, until no more longwave is available for absorption.
The amount of heat energy added to the atmosphere by the greenhouse effect is controlled by the concentration of greenhouse gases in the Earth's atmosphere. All of the major greenhouse gases have increased in concentration since the beginning of the Industrial Revolution (about 1700 AD). As a result of these higher concentrations, scientists predict that the greenhouse effect will be enhanced and the Earth's climate will become warmer. Predicting the amount of warming is accomplished by computer modeling. Computer models suggest that a doubling of the concentration of the main greenhouse gas, carbon dioxide, may raise the average global temperature between 1 and 3° Celsius. However, the numeric equations of computer models do not accurately simulate the effects of a number of possible negative feedbacks. For example, many of the models cannot properly simulate the negative effects that increased cloud cover would have on the radiation balance of a warmer Earth. Increasing the Earth's temperature would cause the oceans to evaporate greater amounts of water, causing the atmosphere to become cloudier. These extra clouds would then reflect a greater proportion of the Sun's energy back to space reducing the amount of solar radiation absorbed by the atmosphere and the Earth's surface. With less solar energy being absorbed at the surface, the effects of an enhanced greenhouse effect may be counteracted.
A number of gases are involved
in the human caused enhancement of the greenhouse effect
(see Table
7h-1 below). These gases include: carbon
dioxide (CO2); methane (CH4); nitrous
oxide (N2O); chlorofluorocarbons (CFxClx);
and tropospheric
ozone (O3). Of these gases, the single
most important gas is carbon
dioxide which accounts for about 55% of the
change in the intensity of the Earth's greenhouse effect.
The contributions of the other gases are 25% for chlorofluorocarbons,
15% for methane,
and 5% for nitrous
oxide. Ozone's contribution
to the enhancement of
greenhouse effect is still yet to be quantified.
Average concentrations of atmospheric carbon dioxide in the year 2005 were about 380 parts per million (see Figure 7a-1). Prior to 1700, levels of carbon dioxide were about 280 parts per million. This increase in carbon dioxide in the atmosphere is primarily due to the activities of humans. Beginning in 1700, societal changes brought about by the Industrial Revolution increased the amount of carbon dioxide entering the atmosphere. The major sources of this gas include fossil fuel combustion for industry, transportation, space heating, electricity generation and cooking; and vegetation changes in natural prairie, woodland, and forested ecosystems. Emissions from fossil fuel combustion account for about 65% of the extra carbon dioxide now found in our atmosphere. The remaining 35% is derived from deforestation and the conversion of prairie, woodland, and forested ecosystems primarily into agricultural systems. Natural ecosystems can hold 20 to 100 times more carbon dioxide per unit area than agricultural systems.
Artificially created chlorofluorocarbons are the strongest greenhouse gas per molecule. However, low concentrations in the atmosphere reduce their overall importance in the enhancement of the greenhouse effect. Current measurements in the atmosphere indicate that the concentration of these chemicals may soon begin declining because of reduced emissions. Reports of the development of ozone holes over the North and South Poles and a general decline in global stratospheric ozone levels over the last two decades has caused many nations to cutback on their production and use of these chemicals. In 1987, the signing of the Montreal Protocol agreement by forty-six nations established an immediate timetable for the global reduction of chlorofluorocarbons production and use.
Since 1750, methane concentrations in the atmosphere have increased by more than 150%. The primary sources for the additional methane added to the atmosphere (in order of importance) are rice cultivation, domestic grazing animals, termites, landfills, coal mining, and oil and gas extraction. Anaerobic conditions associated with rice paddy flooding results in the formation of methane gas. However, an accurate estimate of how much methane is being produced from rice paddies has been difficult to obtain. More than 60% of all rice paddies are found in India and China where scientific data concerning emission rates are unavailable. Nevertheless, scientists believe that the contribution of rice paddies is large because this form of crop production has more than doubled since 1950. Grazing animals release methane to the environment as a result of herbaceous digestion. Some researchers believe the addition of methane from this source has more than quadrupled over the last century. Termites also release methane through similar processes. Land-use change in the tropics, due to deforestation, ranching, and farming, may be causing termite numbers to expand. If this assumption is correct, the contribution from these insects may be important. Methane is also released from landfills, coal mines, and gas and oil drilling. Landfills produce methane as organic wastes decompose over time. Coal, oil, and natural gas deposits release methane to the atmosphere when these deposits are excavated or drilled.
The average concentration of nitrous oxide in the atmosphere is now increasing at a rate of 0.2 to 0.3% per year. Sources for this increase include land-use conversion; fossil fuel combustion; biomass burning; and soil fertilization. Most of the nitrous oxide added to the atmosphere each year comes from deforestation and the conversion of forest, savanna and grassland ecosystems into agricultural fields and rangeland. Both of these processes reduce the amount of nitrogen stored in living vegetation and soil through the decomposition of organic matter. Nitrous oxide is also released into the atmosphere when fossil fuels and biomass are burned. However, the combined contribution of these sources to the increase of this gas in the atmosphere is thought to be minor. The use of nitrate and ammonium fertilizers to enhance plant growth is another source of nitrous oxide. Accurate measurements of how much nitrous oxide is being released from fertilization have been difficult to obtain. Estimates suggest that the contribution from this source may represent from 50% to 0.2% of nitrous oxide added to the atmosphere annually.
Ozone's role in the enhancement of the greenhouse effect has been difficult to determine scientifically. Accurate measurements of past long-term (more than 25 years in the past) levels of this gas in the atmosphere are currently unavailable. Concentrations of ozone gas are found in two different regions of the Earth's atmosphere. The majority of the ozone (about 97%) found in the atmosphere is localized in the stratosphere at an altitude of 15 to 55 kilometers above the Earth's surface. In recent years, the concentration of the stratospheric ozone has been decreasing because of the buildup of chlorofluorocarbons in the atmosphere (see Lecture 7e). Since the late 1970s, scientists have discovered that total column ozone amounts over Antarctica in the springtime have decreased by as much as 70%. Satellite measurements have indicated that the zone from 65° North to 65° South latitude has had a 3% decrease in stratospheric ozone since 1978. Ozone is also highly concentrated at the Earth's surface. Most of this ozone is created as an artificial by product of photochemical smog.
In summary, the greenhouse effect causes the atmosphere to trap more heat energy at the Earth's surface and within the atmosphere by absorbing and re-emitting longwave energy. Of the longwave energy emitted back to space, 90% is intercepted and absorbed by greenhouse gases. Without the greenhouse effect the Earth's average global temperature would be -18° Celsius, rather than the present 15° Celsius. In the last few centuries, the activities of humans have directly or indirectly caused the concentration of the major greenhouse gases to increase. Scientists predict that this increase may enhance the greenhouse effect making the planet warmer. Some experts estimate that the Earth's average global temperature has already increased by 0.3 to 0.6° Celsius, since the beginning of this century, because of this enhancement. Predictions of future climates indicate that by the middle of the next century the Earth's global temperature may be 1 to 3° Celsius higher than today.
Table 7h-1: Gases involved in the Greenhouse Effect: past and present concentration and sources.
Greenhouse Gas
Concentration
1750
Concentration
2003
|Percent Change|
Natural and Anthropogenic Sources
|Carbon Dioxide||280 ppm||376 ppm||34%||Organic decay; Forest fires; Volcanoes; Burning fossil fuels; Deforestation; Land-use change|
|Methane||0.71 ppm||1.79 ppm||152%||Wetlands; Organic decay; Termites; Natural gas & oil extraction; Biomass burning; Rice cultivation; Cattle; Refuse landfills|
|Nitrous Oxide||270 ppb||319 ppb||18%||Forests; Grasslands; Oceans; Soils; Soil cultivation; Fertilizers; Biomass burning; Burning of fossil fuels|
|Chlorofluorocarbons (CFCs)||0||880 ppt||Not Applicable||Refrigerators; Aerosol spray propellants; Cleaning solvents|
|Ozone||Unknown||Varies with latitude and altitude in the atmosphere||Global levels have generally decreased in the stratosphere and increased near the Earth's surface||Created naturally by the action of sunlight on molecular oxygen and artificially through photochemical smog production|

Question: what is very different from the place

மேற்பரப்பு பூமியின் நிலம் இடத்திற்கு

The place of the earth is very different from the place.

Question: the place of what is very different from the place

the place of what is very different from the place

Question: the earth is very different from what

Question: what is very different from the earth

மேற்பரப்பு பூமியின் நிலம் இடத்திற்கு

Question: how different is the earth from the earth

மிக வேறுபட்டுள்ளது

how different is the earth from the earth

Question: is the earth different or different from the earth

வேறுபட்டுள்ளது

is the earth different or different from the earth

The place of the earth is very different from the place .

மேற்பரப்பு பூமியின் நிலம் இடத்திற்கு இடம் மிக வேறுபட்டுள்ளது.

மேற்பரப்பு பூமியின் நிலம் இடத்திற்கு இடம் மிக வேறுபட்டுள்ளது.

The place of the earth is very different from the place.

The place of the earth is very different from the place.

The earth's cultivation is formed in the period by the detonic acts and arithmetic in the period by the detonic varieties of the cultivation, the cooling and deforested systems are also exposed by the water (precipitation) in the period by the heat and the resin.

காலப்போக்கில்

மேற்பரப்பில்

ரசாயனங்களாலும்

தாக்கப்படுகின்றன

Impact craters on Mars, Mercury and the Moon
Impact events have even affected the atmospheres of the giant gaseous planets, as exemplified by the impact of comet Shoemaker-Levy 9 with Jupiter in 1994, which produced Earth-size blotches in the atmosphere.
Near-infrared image of the Shoemaker-Levy 9 impact event on Jupiter.
Our own planet does not look as battered as Mercury or the Moon, but appearances are deceiving. The Earth has been the target of approximately 10 times more impacting objects than the Moon, producing over 3 million impact craters from 1 km in diameter to more than 1000 km in diameter. However, other geologic processes on Earth, like plate subduction, mountain building, erosion, and volcanism, destroy impact craters and mask their effect on our planet. Only about 160 surviving impact craters have been found thus far.
Perhaps the most
infamous of these impact craters is the ~180 km diameter Chicxulub
impact crater on the Yucatan Peninsula of Mexico. Studies of the
Chicxulub impact event and the mass extinction event that occurred on Earth 65
million years ago have demonsrated that impact cratering can affect the biologic
evolution of a planet as well as the geologic evolution of a
planet.
This web site will, over a period of several years, explore the environmental effects of impact cratering and the biological consequences of those effects. Ideas will be explored and explained as they appear in the scientific literature so that students, teachers, and the general public can follow the exploration of scientists as they try to unravel the secrets of life, its origin, and evolution on Earth and the possibility of life elsewhere in the solar system. New sections will be added to this site as warrented by new studies, so revisit the site in the future to read about the progress being made.
LUNAR
CATACLYSM
ORIGIN OF LIFE
IMPACT CRATERING MAP
This web site is based on information originally created for the NASA/UA Space Imagery Centerís Impact Cratering Series.
Concept and content by David A. Kring.
Design, graphics, and images by Jake Bailey and David A. Kring.
Any use of the information and images requires permission of the Space Imagery Center and/or David A. Kring (now at LPI).

Question: what is water

The earth's cultivation is formed in the period by the detonic acts and arithmetic in the period by the detonic varieties of the cultivation, the cooling and deforested systems are also exposed by the water (precipitation) in the period by the heat and the resin.

Question: the cooling and deforested systems are exposed by heat and resin and what else

the cooling and deforested systems are exposed by heat and resin and what else

Question: how is the earths cultivation formed

டெக்டோனிக் செயல்கள்

Question: detonic acts and what other act formed the earth's cultivation

detonic acts and what other act formed the earth's cultivation

Question: what are the two forces that expose the cooling and deforested systems of the earth

வெப்ப சுழற்சி மற்றும் ரசாயனங்களாலும்

what are the two forces that expose the cooling and deforested systems of the earth

Question: along with heat and deforesting, what is another element that exposes the cooling and

ரசாயனங்களாலும்

along with heat and deforesting, what is another element that exposes the cooling and

Question: what exposes the cooling and deforested systems of the earth

what exposes the cooling and deforested systems of the earth

The earth 's cultivation is formed in the period by the detonic acts and arithmetic in the period by the detonic varieties of the cultivation , the cooling and deforested systems are also exposed by the water ( precipitation ) in the period by the heat and the resin .

பூமியின் மேற்பரப்பு டெக்டோனிக் செயல்கள் மற்றும் அரித்தலால் காலப்போக்கில் உருமாறிக் கொண்டே இருக்கிறது மேற்பரப்பில் டெக்டோனிக் பலகை நகர்தலால் ஏற்படும் குவிந்த மற்றும் தகர்ந்த அமைப்புகள் மேலும் மழைகளால் (precipitation) சிதைவதும் வெப்ப சுழற்சி மற்றும் ரசாயனங்களாலும் தாக்கப்படுகின்றன.

பூமியின் மேற்பரப்பு டெக்டோனிக் செயல்கள் மற்றும் அரித்தலால் காலப்போக்கில் உருமாறிக் கொண்டே இருக்கிறது மேற்பரப்பில் டெக்டோனிக் பலகை நகர்தலால் ஏற்படும் குவிந்த மற்றும் தகர்ந்த அமைப்புகள் மேலும் மழைகளால் (precipitation) சிதைவதும் வெப்ப சுழற்சி மற்றும் ரசாயனங்களாலும் தாக்கப்படுகின்றன.

The earth's cultivation is formed in the period by the detonic acts and arithmetic in the period by the detonic varieties of the cultivation, the cooling and deforested systems are also exposed by the water (precipitation) in the period by the heat and the resin.

The earth's cultivation is formed in the period by the detonic acts and arithmetic in the period by the detonic varieties of the cultivation, the cooling and deforested systems are also exposed by the water (precipitation) in the period by the heat and the resin.

Thus, there are the shadows of the shadows, the shadows of the shadows, the shadows of the shadows and the shadows of the shadows.

"கண்டங்களின்

திண்மத்தையுடைய

அன்டிசைட்களால்

Question: what are the shadows of the shadows

Thus, there are the shadows of the shadows, the shadows of the shadows, the shadows of the shadows and the shadows of the shadows.

Question: what are the shadows of

Thus , there are the shadows of the shadows , the shadows of the shadows , the shadows of the shadows and the shadows of the shadows .

கண்டங்களின் மேலோடு குறைந்த திண்மத்தையுடைய தீப்பாறைகள், கிரானைட் மற்றும் அன்டிசைட்களால் (andesite) ஆனது.

கண்டங்களின் மேலோடு குறைந்த திண்மத்தையுடைய தீப்பாறைகள், கிரானைட் மற்றும் அன்டிசைட்களால் (andesite) ஆனது.

Thus, there are the shadows of the shadows, the shadows of the shadows, the shadows of the shadows and the shadows of the shadows.

Thus, there are the shadows of the shadows, the shadows of the shadows, the shadows of the shadows and the shadows of the shadows.

Those who are in the midst of the covenant, and who are in the midst of the covenant, and who are in the midst of the covenant.

Though the bacteria are 5% in the Earth's surface, they are 75% in the surface of their observations.

"படிவுப்பாறைகள்

அழுத்தத்தினால்

தோற்றுவிக்கப்படுகின்றன

"படிவுப்பாறைகள்

மேற்பரப்பில்

WEATHERING AND SEDIMENTARY ROCKS
Weathering - Process which acts at the earth's surface to decompose and breakdown rocks.
Erosion - The movement of weathered material from the site of weathering. Primary agent is gravity, but gravity acts in concert with running water.
Types of Weathering
Mechanical or Physical - the breakdown of rock material into smaller and smaller pieces with no change in the chemical composition of the weathered material.
Chemical - the breakdown of rocks by chemical agents. Obviously the chief chemical agent is water which carries dissociated carbonic acid.
Mechanical Weathering
Expansion and Contraction - the thermal heating and cooling of rocks causing expansion and contraction. Frost Action - Water freezes at night and expands because the solid occupies greater volume. Action wedges the rocks apart. Requires adequate supply of moisture; moisture must be able to enter rock or soil; and temperature must move back and forth over freezing point. Exfoliation - process in which curved plates of rock are stripped from a larger rock mass. Example Half Dome. Exact mechanism uncertain but probably due to unloading. Other types - Cracking of rocks by plant roots and burrowing animals. Chemical Weathering
Expansion and Contraction - the thermal heating and cooling of rocks causing expansion and contraction.
Frost Action - Water freezes at night and expands because the solid occupies greater volume. Action wedges the rocks apart. Requires adequate supply of moisture; moisture must be able to enter rock or soil; and temperature must move back and forth over freezing point.
Exfoliation - process in which curved plates of rock are stripped from a larger rock mass. Example Half Dome. Exact mechanism uncertain but probably due to unloading.
Other types - Cracking of rocks by plant roots and burrowing animals.
Chemical Weathering
Factors which effect the rate of chemical weathering are:
Particle size - Smaller the particle size the greater the surface area and hence the more rapid the weathering
Composition
Climate (See Figure)
Type and amount of vegetation
Chemical Weathering of Rocks
Show Figure and explain formation of carbonic acid
H2O + CO2 ------->> H2CO3
Acid then dissociates and the following happens:
2KAlSi3O8 (feldspar)+ 2H+ + H2O ------->> Al2Si2O5(OH)4 (clay)+ 2K+ + 4SiO2
Weathering of Igneous Minerals
Products of Weathering Figure:
Quartz - slow process and largely ineffective. Quartz remains quartz. Grains are rounded.
Feldspar - weathers to clay with the cations Na, Ca, and K going into solution. Clays that can form include kaolinite (pure aluminum silicate), illite and montmorillonite. Factors which dictate clay formation are (a) climate; (b) time; (c) parent material.
Muscovite - Same as above
Ferromagnesian minerals - weather to clay plus highly insoluble iron oxides, essentially varieties of limonite (rust).
Rates of Weathering
Studied by S.S. Goldich (Figure) and found to be inverse of Bowen's Reaction Series. Why? A function of equilibrium, the higher the temperature of formation of a mineral the more unstable it is at the earth's surface. Hence olivine weathers the most rapidly.
Soils
Soil - Surficial material that forms due to weathering. Includes an organic component. Many different soil types. Factors effecting their formation are:
1) Climate
2) Relief
3) Bedrock material
4) Time
Classification of soils varies depending on the classifier. Geologists use a very simple classification based largely on materials added or removed from the soil during its formation.
Soil consists of four major zones (horizons) (Figure).
1. O horizon - Organic layer
2. A horizon - Zone of leaching - Cations are leached from this horizon by strongly acid solutions generated in the O horizon
3. B horizon - Zone of Accumulation - Cations leached out of the A horizon accumulate here. Horizon consists of clays, iron and aluminum oxides. Deposition due to neutralization of acid solutions.
4. C horizon - Partially decomposed parent material. Lower most zone.
Soil Types
Pedalfer - Named for the abundance of Al and Fe in the B horizon. Occur in temperate, humid climates. Lie generally east of the Mississippi River, correspond with 63 cm/yr rainfall contour. Pedocal - Named for the accumulation of calcium carbonate in the B horizon. Characteristic of temperate, dry climates. Lie generally west of Miss River. Poorly developed A horizon, B horizon is caliche (calcium carbonate). Laterites - Tropical soils thought to represent the end products of weathering. Characterized by stark red color and abundance of iron and aluminum oxides and lesser clay minerals. Requires abundant rainfall. SEDIMENTARY ROCKS Sedimentary Rocks - Layered or stratified rocks formed at or near the earth's surface in response to the processes of weathering, erosion, transportation and deposition. Rock Cycle All rocks discussed in this class are a part of the rock cycle (Figure).
Pedalfer - Named for the abundance of Al and Fe in the B horizon. Occur in temperate, humid climates. Lie generally east of the Mississippi River, correspond with 63 cm/yr rainfall contour.
Pedocal - Named for the accumulation of calcium carbonate in the B horizon. Characteristic of temperate, dry climates. Lie generally west of Miss River. Poorly developed A horizon, B horizon is caliche (calcium carbonate).
Laterites - Tropical soils thought to represent the end products of weathering. Characterized by stark red color and abundance of iron and aluminum oxides and lesser clay minerals. Requires abundant rainfall.
SEDIMENTARY ROCKS
Sedimentary Rocks - Layered or stratified rocks formed at or near the earth's surface in response to the processes of weathering, erosion, transportation and deposition.
Rock Cycle
All rocks discussed in this class are a part of the rock cycle (Figure).
Sedimentary Cycle (Figure)
Processes
Transportation
Transportation
Deposition
Deposition
Lithification
Lithification
Single most important characteristic of sedimentary rocks is layering. Occurs in response to changes in conditions at the site of deposition. Sedimentary rocks cover 75% of the earth's surface, but amount to only 5% of the outer 10 km.
Origin of Sedimentary Material
Derived directly from pre-existing rocks. Ex. quartz.
Derived from weathered products of these rocks. Ex. clay.
Produced by chemical precipitation. Ex. calcite.
First two processes result in detrital or clastic rocks. Third produces nondetrital or chemical sedimentary rocks.
Minerals of Sedimentary Rocks
Classification of Sedimentary Rocks
Texture - Size, shape and arrangement of particles.
Wentworth Size Scale
Boulder
>256 mm
Conglomerate
Cobble
64-256 mm
Pebble
2-64 mm
Sand
1/16-2 mm
Sandstone
Silt
1/256-1/16 mm
Siltstone
Clay
<1/256 mm
Shale
Conglomerate - Detrital rock made up of more or less rounded fragments, an appreciable percentage of which are pebble size or larger
Sandstone - Consists primarily of grains in the sand size range. Dominant mineral in sandstones is always quartz. Further subdivide sandstones based on other minerals present. Quartz sandstone is 99% quartz. Arkose contains both quartz and feldspar. Graywacke is a garbage sandstone with quartz, feldspar, mica and rock fragments. Often has a significant fine-grained component and is poorly sorted.
Siltstone - Rare sedimentary rock composed mostly of silt sized particles. Rare because dominant mineral is quartz which does not like to get any smaller than sand size. Many siltstones thought to form by glacial grinding of sand-sized quartz grains.
Shale - Most common of the sedimentary rocks. Composed primarily of clay minerals. Often tends to split into flat sheets due to the mica-like cleavage of clay minerals.
Limestone - Formed by the precipitation of calcite from seawater. Most form in marine environments, but also around hot springs, as a crust in desert soils, and as cave formation.
Dolostone - Composed of the mineral dolomite. Probably starts life as limestone then is altered to dolostone by Mg-bearing solutions in arid environments.
Evaporites - Formed by partial to complete evaporation of seawater in enclosed basins. Forms salts and gypsum.
Organic Rocks - Rocks formed by the accumulation of organic material. Ex. coquina and chalk.
Coal - Rock composed of lithified plant material.
Abundance of Sedimentary Rocks (Figure)
Sedimentary Structures (Figure)
A) Structures formed during deposition
a) Current - asymmetrical - Rivers
b) Oscillation - symmetrical - Beaches
B) Structures formed after deposition
C) Other features

Question: what percentage of bacteria are on the surface of the earth

Those who are in the midst of the covenant, and who are in the midst of the covenant, and who are in the midst of the covenant.

Though the bacteria are 5% in the Earth's surface, they are 75% in the surface of their observations.

what percentage of bacteria are on the surface of the earth

Question: what percentage of bacteria are on earth's surface

what percentage of bacteria are on earth's surface

Question: who are those who are in the covenant

Those who are in the midst of the covenant

தோற்றுவிக்கப்படுகின்றன

Those who are in the midst of the covenant

Question: who are in the midst of the covenant

Question: what is 5% of the earths surface

Question: how many bacteria are on the surface of the earth

how many bacteria are on the surface of the earth

Those who are in the midst of the covenant , and who are in the midst of the covenant , and who are in the midst of the covenant .

Though the bacteria are 5 % in the Earth 's surface , they are 75 % in the surface of their observations .

படிவுப்பாறைகள் வண்டல்கள் அழுத்தத்தினால் உருமாறி ஒன்று சேர்ந்து தோற்றுவிக்கப்படுகின்றன. படிவுப்பாறைகள் பூமியின் மேலோட்டில் 5% உள்ளது எனினும் அவை கண்டங்களின் மேற்பரப்பில் 75% மாக உள்ளது.

படிவுப்பாறைகள் வண்டல்கள் அழுத்தத்தினால் உருமாறி ஒன்று சேர்ந்து தோற்றுவிக்கப்படுகின்றன.

படிவுப்பாறைகள் பூமியின் மேலோட்டில் 5% உள்ளது எனினும் அவை கண்டங்களின் மேற்பரப்பில் 75% மாக உள்ளது.

Those who are in the midst of the covenant, and who are in the midst of the covenant, and who are in the midst of the covenant. Though the bacteria are 5% in the Earth's surface, they are 75% in the surface of their observations.

Those who are in the midst of the covenant, and who are in the midst of the covenant, and who are in the midst of the covenant.

Though the bacteria are 5% in the Earth's surface, they are 75% in the surface of their observations.

It happens when it is created.

The most common species on earth are curts, fieldspar, amphibole, myc, pyroxene, and olivin.

உருப்பெயருவதால்

சிலிக்கேட்டுகள்

பெல்ட்ஸ்பார்

Question: when does it happen to curts

It happens when it is created.

The most common species on earth are curts, fieldspar, amphibole, myc, pyroxene, and olivin.

Question: what is the most common species on earth

It happens when it is created.

what is the most common species on earth

Question: curts, fieldspar, amphibole, myc, pyroxene, and

மிக அதிகமாகக்

It happens when it is created.

curts, fieldspar, amphibole, myc, pyroxene, and

Question: when does it happen

It happens when it is created.

Question: what are the most common species on earth

curts, fieldspar, amphibole, myc, pyroxene, and olivin

குவார்ட்ஸ் , பெல்ட்ஸ்பார் ( feldspar ) , ஆம்பிபோல் ( amphibole ) , மைக்கா , பைராக்சீன் ( pyroxene ) மற்றும் ஒலிவைன் ( olivine ) ஆகும் .

It happens when it is created.

curts , fieldspar , amphibole , myc , pyroxene , and olivin

what are the most common species on earth

The most common species on earth are curts , fieldspar , amphibole , myc , pyroxene , and olivin .

உருப்பெயருவதால் ஏற்படுபவை. பூமியில் மிக அதிகமாகக் காணப்படும் சிலிக்கேட்டுகள் குவார்ட்ஸ், பெல்ட்ஸ்பார் (feldspar), ஆம்பிபோல் (amphibole), மைக்கா, பைராக்சீன் (pyroxene) மற்றும் ஒலிவைன் (olivine) ஆகும்.

உருப்பெயருவதால் ஏற்படுபவை.

பூமியில் மிக அதிகமாகக் காணப்படும் சிலிக்கேட்டுகள் குவார்ட்ஸ், பெல்ட்ஸ்பார் (feldspar), ஆம்பிபோல் (amphibole), மைக்கா, பைராக்சீன் (pyroxene) மற்றும் ஒலிவைன் (olivine) ஆகும்.

It happens when it is created. The most common species on earth are curts, fieldspar, amphibole, myc, pyroxene, and olivin.

The most common species on earth are curts, fieldspar, amphibole, myc, pyroxene, and olivin.

It is commonly seen by the carpentry (such as it is seen in the heads of the sunshine), the arthrose and the dolomite.

கார்பனேட்டுகள்

Question: the arthrose and dolomite are commonly seen in what profession

It is commonly seen by the carpentry (such as it is seen in the heads of the sunshine), the arthrose and the dolomite.

the arthrose and dolomite are commonly seen in what profession

Question: what two types of flowers are commonly seen in carpentry

அராகோனைட்டு மற்றும் டோலோமைட்டு

what two types of flowers are commonly seen in carpentry

Question: the arthrose and dolomite are commonly seen in which profession

the arthrose and dolomite are commonly seen in which profession

Question: what are the three types of dolomite

Question: the arthrose is commonly seen in the heads of what

the arthrose is commonly seen in the heads of what

Question: where can the arthrose be seen in carpentry

, அராகோனைட்டு மற்றும் டோலோமைட்டு ஆகும் .

where can the arthrose be seen in carpentry

It is commonly seen by the carpentry ( such as it is seen in the heads of the sunshine ) , the arthrose and the dolomite .

பொதுவாக காணப்படும் கார்பனேட்டுகள் கால்சைட்டு (சுண்ணாம்பு கற்களில் காணப்படுவது), அராகோனைட்டு மற்றும் டோலோமைட்டு ஆகும்.

பொதுவாக காணப்படும் கார்பனேட்டுகள் கால்சைட்டு (சுண்ணாம்பு கற்களில் காணப்படுவது), அராகோனைட்டு மற்றும் டோலோமைட்டு ஆகும்.

It is commonly seen by the carpentry (such as it is seen in the heads of the sunshine), the arthrose and the dolomite.

It is commonly seen by the carpentry (such as it is seen in the heads of the sunshine), the arthrose and the dolomite.

It’s all in the pitch and it’s all in the pitch and it’s all in the pitch.

But and this is a matter of work and creation. It is between the lithium, lithium, lithium and lithium.

எல்லாவாற்றிற்கும்

உயிர்க்கோளத்திற்கு

Globally, the 20th century was marked by: (a) two devastating world wars; (b) the Great Depression of the 1930s; (c) the end of vast colonial empires; (d) rapid advances in science and technology, from the first airplane flight at Kitty Hawk, North Carolina (US) to the landing on the moon; (e) the Cold War between the Western alliance and the Warsaw Pact nations; (f) a sharp rise in living standards in North America, Europe, and Japan; (g) increased concerns about the environment, including loss of forests, shortages of energy and water, the decline in biological diversity, and air pollution; (h) the onset of the AIDS epidemic; and (i) the ultimate emergence of the US as the only world superpower. The planet's population continues to explode: from 1 billion in 1820, to 2 billion in 1930, 3 billion in 1960, 4 billion in 1974, 5 billion in 1988, and 6 billion in 2000. For the 21st century, the continued exponential growth in science and technology raises both hopes (e.g., advances in medicine) and fears (e.g., development of even more lethal weapons of war).
Geography ::World
Geographic overview:
The surface of the earth is approximately 70.9% water and 29.1% land. The former portion is divided into large water bodies termed oceans. The World Factbook recognizes and describes five oceans, which are in decreasing order of size: the Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean, and Arctic Ocean.
The land portion is generally divided into several, large, discrete landmasses termed continents. Depending on the convention used, the number of continents can vary from five to seven. The most common classification recognizes seven, which are (from largest to smallest): Asia, Africa, North America, South America, Antarctica, Europe, and Australia. Asia and Europe are sometimes lumped together into a Eurasian continent resulting in six continents. Alternatively, North and South America are sometimes grouped as simply the Americas, resulting in a continent total of six (or five, if the Eurasia designation is used).
North America is commonly understood to include the island of Greenland, the isles of the Caribbean, and to extend south all the way to the Isthmus of Panama. The easternmost extent of Europe is generally defined as being the Ural Mountains and the Ural River; on the southeast the Caspian Sea; and on the south the Caucasus Mountains, the Black Sea, and the Mediterranean. Africa's northeast extremity is frequently delimited at the Isthmus of Suez, but for geopolitical purposes, the Egyptian Sinai Peninsula is often included as part of Africa. Asia usually incorporates all the islands of the Philippines, Malaysia, and Indonesia. The islands of the Pacific are often lumped with Australia into a "land mass" termed Oceania or Australasia.
Although the above groupings are the most common, different continental dispositions are recognized or taught in certain parts of the world, with some arrangements more heavily based on cultural spheres rather than physical geographic considerations.
top fifteen World Factbook entities ranked by size:
Pacific Ocean 155.557 million sq km; Atlantic Ocean 76.762 million sq km; Indian Ocean 68.556 million sq km; Southern Ocean 20.327 million sq km; Russia 17,098,242 sq km; Arctic Ocean 14.056 million sq km; Antarctica 14 million sq km; Canada 9,984,670 sq km; United States 9,826,675 sq km; China 9,596,961 sq km; Brazil 8,514,877 sq km; Australia 7,741,220 sq km; European Union 4,324,782 sq km; India 3,287,263 sq km; Argentina 2,780,400 sq km
the land boundaries in the world total 251,060 km (not counting shared boundaries twice); two nations, China and Russia, each border 14 other countries
note:45 nations and other areas are landlocked, these include: Afghanistan, Andorra, Armenia, Austria, Azerbaijan, Belarus, Bhutan, Bolivia, Botswana, Burkina Faso, Burundi, Central African Republic, Chad, Czech Republic, Ethiopia, Holy See (Vatican City), Hungary, Kazakhstan, Kosovo, Kyrgyzstan, Laos, Lesotho, Liechtenstein, Luxembourg, Macedonia, Malawi, Mali, Moldova, Mongolia, Nepal, Niger, Paraguay, Rwanda, San Marino, Serbia, Slovakia, Swaziland, Switzerland, Tajikistan, Turkmenistan, Uganda, Uzbekistan, West Bank, Zambia, Zimbabwe; two of these, Liechtenstein and Uzbekistan, are doubly landlocked
note:94 nations and other entities are islands that border no other countries, they include: American Samoa, Anguilla, Antigua and Barbuda, Aruba, Ashmore and Cartier Islands, The Bahamas, Bahrain, Baker Island, Barbados, Bermuda, Bouvet Island, British Indian Ocean Territory, British Virgin Islands, Cape Verde, Cayman Islands, Christmas Island, Clipperton Island, Cocos (Keeling) Islands, Comoros, Cook Islands, Coral Sea Islands, Cuba, Cyprus, Dominica, Falkland Islands (Islas Malvinas), Faroe Islands, Fiji, French Polynesia, French Southern and Antarctic Lands, Greenland, Grenada, Guam, Guernsey, Heard Island and McDonald Islands, Howland Island, Iceland, Isle of Man, Jamaica, Jan Mayen, Japan, Jarvis Island, Jersey, Johnston Atoll, Kingman Reef, Kiribati, Madagascar, Maldives, Malta, Marshall Islands, Martinique, Mauritius, Mayotte, Federated States of Micronesia, Midway Islands, Montserrat, Nauru, Navassa Island, New Caledonia, New Zealand, Niue, Norfolk Island, Northern Mariana Islands, Palau, Palmyra Atoll, Paracel Islands, Philippines, Pitcairn Islands, Puerto Rico, Reunion, Saint Barthelemy, Saint Helena, Saint Kitts and Nevis, Saint Lucia, Saint Pierre and Miquelon, Saint Vincent and the Grenadines, Samoa, Sao Tome and Principe, Seychelles, Singapore, Solomon Islands, South Georgia and the South Sandwich Islands, Spratly Islands, Sri Lanka, Svalbard, Tokelau, Tonga, Trinidad and Tobago, Turks and Caicos Islands, Tuvalu, Vanuatu, Virgin Islands, Wake Island, Wallis and Futuna, Taiwan
a variety of situations exist, but in general, most countries make the following claims measured from the mean low-tide baseline as described in the 1982 UN Convention on the Law of the Sea: territorial sea - 12 nm, contiguous zone - 24 nm, and exclusive economic zone - 200 nm; additional zones provide for exploitation of continental shelf resources and an exclusive fishing zone; boundary situations with neighboring states prevent many countries from extending their fishing or economic zones to a full 200 nm
the rapid depletion of nonrenewable mineral resources, the depletion of forest areas and wetlands, the extinction of animal and plant species, and the deterioration in air and water quality (especially in some countries of Eastern Europe, the former USSR, and China) pose serious long-term problems that governments and peoples are only beginning to address
large areas subject to overpopulation, industrial disasters, pollution (air, water, acid rain, toxic substances), loss of vegetation (overgrazing, deforestation, desertification), loss of wildlife, soil degradation, soil depletion, erosion; global warming becoming a greater concern
note:over two-thirds of the world's 785 million illiterate adults are found in only eight countries (Bangladesh, China, Egypt, Ethiopia, India, Indonesia, Nigeria, and Pakistan); of all the illiterate adults in the world, two-thirds are women; extremely low literacy rates are concentrated in three regions, the Arab states, South and West Asia, and Sub-Saharan Africa, where around one-third of the men and half of all women are illiterate (2005 est.)
Global output rose by 3.8% in 2008, down from 5.2% in 2007. Among major economies, growth was led by China (9.8%), Russia (7.4%), and India (7.3%). Worldwide, nations varied widely in their growth results, with Macau (15%), Azerbaijan (13.2%), and Angola (11.6%), registering the highest. Growth rates slowed in all the major industrial countries and most developing countries, because of uncertainties in the financial markets and lowered consumer confidence. Externally, the nation-state, as a bedrock economic-political institution, is steadily losing control over international flows of people, goods, funds, and technology. Internally, the central government often finds its control over resources slipping as separatist regional movements - typically based on ethnicity - gain momentum, e.g., in many of the successor states of the former Soviet Union, in the former Yugoslavia, in India, in Iraq, in Indonesia, and in Canada. Externally, the central government is losing decisionmaking powers to international bodies, notably the EU. In Western Europe, governments face the difficult political problem of channeling resources away from welfare programs in order to increase investment and strengthen incentives to seek employment. The addition of 80 million people each year to an already overcrowded globe is exacerbating the problems of pollution, desertification, underemployment, epidemics, and famine. Because of their own internal problems and priorities, the industrialized countries devote insufficient resources to deal effectively with the poorer areas of the world, which, at least from an economic point of view, are becoming further marginalized. The introduction of the euro as the common currency of much of Western Europe in January 1999, while paving the way for an integrated economic powerhouse, poses economic risks because of varying levels of income and cultural and political differences among the participating nations. The terrorist attacks on the US on 11 September 2001 accentuated a growing risk to global prosperity, illustrated, for example, by the reallocation of resources away from investment to anti-terrorist programs. The opening of war in March 2003 between a US-led coalition and Iraq added new uncertainties to global economic prospects. The complex political difficulties and the high economic cost of establishing domestic order in Iraq became major global problems that continued through 2008.
developed countries 1% to 4% typically; developing countries 5% to 20% typically; national inflation rates vary widely in individual cases, from declining prices in Japan to hyperinflation in one Third World country (Zimbabwe); inflation rates have declined for most countries for the last several years, held in check by increasing international competition from several low wage countries
dominated by the onrush of technology, especially in computers, robotics, telecommunications, and medicines and medical equipment; most of these advances take place in OECD nations; only a small portion of non-OECD countries have succeeded in rapidly adjusting to these technological forces; the accelerated development of new industrial (and agricultural) technology is complicating already grim environmental problems
the whole range of industrial and agricultural goods and services
top ten - share of world trade:
electrical machinery, including computers 14.8%; mineral fuels, including oil, coal, gas, and refined products 14.4%; nuclear reactors, boilers, and parts 14.2%; cars, trucks, and buses 8.9%; scientific and precision instruments 3.5%; plastics 3.4%; iron and steel 2.7%; organic chemicals 2.6%; pharmaceutical products 2.6%; diamonds, pearls, and precious stones 1.9% (2006 est.)
top ten by passengers:
Atlanta (ATL) - 89,379,287; Chicago (ORD) - 76,177,855; London (LHR) - 68,068,304; Tokyo (HND) - 66,823,414; Los Angeles (LAX) - 61,896,075; Paris (CDG) - 59,922,177; Dallas/Fort Worth (DFW) - 59,786,476; Frankfurt (FRA) - 54,161,856; Beijing (PEK) - 53,583,664; Madrid (MAD) - 52,122,702
top ten by cargo (metric tons):
Memphis (MEM) - 3,840,491; Hong Kong (HKG) - 3,773,964; Anchorage (ANC) - 2,825,511; Shanghai (PVG) - 2,559,310; Inch'on (ICN) - 2,555,580; Paris (CDG) - 2,297,896; Tokyo (NRT) - 2,254,421; Frankfurt (FRA) - 2,127,646; Louisville (SDF) - 2,078,947; Miami (MIA) - 1,922,985 (2009)
As of September 2009, incidents of piracy around the world have more than doubled over the comparable time period in 2008; half of all attacks occur in the waters off Somalia, primarily in the Gulf of Aden; other high risk areas include the waters off Nigeria, the South China Sea, and waters off Malaysia
stretching over 250,000 km, the world's 322 international land boundaries separate 194 independent states and 71 dependencies, areas of special sovereignty, and other miscellaneous entities; ethnicity, culture, race, religion, and language have divided states into separate political entities as much as history, physical terrain, political fiat, or conquest, resulting in sometimes arbitrary and imposed boundaries; most maritime states have claimed limits that include territorial seas and exclusive economic zones; overlapping limits due to adjacent or opposite coasts create the potential for 430 bilateral maritime boundaries of which 209 have agreements that include contiguous and non-contiguous segments; boundary, borderland/resource, and territorial disputes vary in intensity from managed or dormant to violent or militarized; undemarcated, indefinite, porous, and unmanaged boundaries tend to encourage illegal cross-border activities, uncontrolled migration, and confrontation; territorial disputes may evolve from historical and/or cultural claims, or they may be brought on by resource competition; ethnic and cultural clashes continue to be responsible for much of the territorial fragmentation and internal displacement of the estimated 6.6 million people and cross-border displacements of 8.6 million refugees around the world as of early 2006; just over one million refugees were repatriated in the same period; other sources of contention include access to water and mineral (especially hydrocarbon) resources, fisheries, and arable land; armed conflict prevails not so much between the uniformed armed forces of independent states as between stateless armed entities that detract from the sustenance and welfare of local populations, leaving the community of nations to cope with resultant refugees, hunger, disease, impoverishment, and environmental degradation
the United Nations High Commissioner for Refugees (UNHCR) estimated that in December 2006 there was a global population of 8.8 million registered refugees and as many as 24.5 million IDPs in more than 50 countries; the actual global population of refugees is probably closer to 10 million given the estimated 1.5 million Iraqi refugees displaced throughout the Middle East (2007)
current situation: approximately 800,000 people, mostly women and children, are trafficked annually across national borders, not including millions trafficked within their own countries; at least 80% of the victims are female and up to 50% are minors; 75% of all victims are trafficked into commercial sexual exploitation; almost two-thirds of the global victims are trafficked intra-regionally within East Asia and the Pacific (260,000 to 280,000 people) and Europe and Eurasia (170,000 to 210,000 people)
Tier 2 Watch List:
Albania, Argentina, Armenia, Azerbaijan, Bahrain, Burundi, Cameroon, Central African Republic, Chad, China, Costa Rica, Cote d'Ivoire, Cyprus, Democratic Republic of the Congo, Dominican Republic, Egypt, Equatorial Guinea, Gabon, The Gambia, Guatemala, Guinea, Guinea-Bissau, Guyana, India, Jordan, Libya, Malaysia, Montenegro, Mozambique, Niger, Panama, Republic of the Congo, Russia, South Africa, Sri Lanka, Tajikistan, Uzbekistan, Venezuela, Zambia, Zimbabwe
Tier 3:
Algeria, Burma, Cuba, Fiji, Iran, Kuwait, Moldova, North Korea, Oman, Papua New Guinea, Qatar, Saudi Arabia, Sudan, Syria (2008)
cocaine: worldwide coca leaf cultivation in 2007 amounted to 232,500 hectares; Colombia produced slightly more than two-thirds of the worldwide crop, followed by Peru and Bolivia; potential pure cocaine production decreased 7% to 865 metric tons in 2007; Colombia conducts an aggressive coca eradication campaign, but both Peruvian and Bolivian Governments are hesitant to eradicate coca in key growing areas; 551 metric tons of export-quality cocaine (85% pure) is documented to have been seized or destroyed in 2005; US consumption of export quality cocaine is estimated to have been in excess of 380 metric tons
opiates:
worldwide illicit opium poppy cultivation continued to increase in 2007, with a potential opium production of 8,400 metric tons, reaching the highest levels recorded since estimates began in mid-1980s; Afghanistan is world's primary opium producer, accounting for 95% of the global supply; Southeast Asia - responsible for 9% of global opium - saw marginal increases in production; Latin America produced 1% of global opium, but most was refined into heroin destined for the US market; if all potential opium was processed into pure heroin, the potential global production would be 1,000 metric tons of heroin in 2007

Question: what are the four elements that make up lithium

வளிமண்டலம் , நீர்க்கோளம் மற்றும் உயிர்க்கோளத்திற்கு இடையே உள்ளது .

It’s all in the pitch and it’s all in the pitch and it’s all in the pitch.

But and this is a matter of work and creation. It is between the lithium, lithium, lithium and lithium.

what are the four elements that make up lithium

Question: what is the difference between lithium and lithium

உருவாகும் செயலுக்கும்

what is the difference between lithium and lithium

Question: what are the elements in the pitch

, நீர்க்கோளம் மற்றும்

Question: what is the difference between the lithium and lithium isotopes

what is the difference between the lithium and lithium isotopes

Question: what are the elements that make up lithium

what are the elements that make up lithium

Question: what is it all in

It ’s all in the pitch and it ’s all in the pitch and it ’s all in the pitch .

But and this is a matter of work and creation . It is between the lithium , lithium , lithium and lithium .

புவியில் எல்லாவாற்றிற்கும் மேலே உள்ள பரப்பு பீடோ அடுக்கு (pedosphere). இது மண்ணால் ஆனது மற்றும் இது மண் உருவாகும் செயலுக்கும் உட்பட்டது. இது லித்தோ அடுக்கு, வளிமண்டலம், நீர்க்கோளம் மற்றும் உயிர்க்கோளத்திற்கு இடையே உள்ளது.

புவியில் எல்லாவாற்றிற்கும் மேலே உள்ள பரப்பு பீடோ அடுக்கு (pedosphere). இது மண்ணால்

ஆனது மற்றும் இது மண் உருவாகும் செயலுக்கும் உட்பட்டது. இது லித்தோ அடுக்கு, வளிமண்டலம், நீர்க்கோளம் மற்றும் உயிர்க்கோளத்திற்கு இடையே உள்ளது.

It’s all in the pitch and it’s all in the pitch and it’s all in the pitch. But and this is a matter of work and creation. It is between the lithium, lithium, lithium and lithium.

It’s all in the pitch and it’s all in the pitch and it’s all in the pitch.

But and this is a matter of work and creation. It is between the lithium, lithium, lithium and lithium.

When observing the stagnation from the earth's output, the very low area is the Dead Sea, which is 418 meters away, and the very high area, according to the 2005 calculations, is an extensive area of 8,848 meters.

மேற்பரப்பிலிருந்து

நிலத்தோற்றத்தைக்

கணக்கெடுப்பின்படி

Question: what is the high area of the dead sea

When observing the stagnation from the earth's output, the very low area is the Dead Sea, which is 418 meters away, and the very high area, according to the 2005 calculations, is an extensive area of 8,848 meters.

Question: what is the name of the area 418 meters away from earth

what is the name of the area 418 meters away from earth

Question: what area is 418 meters away from earth's output

சாக்கடல் ( Dead Sea

what area is 418 meters away from earth's output

Question: how far away is the dead sea from the earth

how far away is the dead sea from the earth

Question: what does the dead sea experience from the earth's output

நிலத்தோற்றத்தைக்

what does the dead sea experience from the earth's output

Question: what does the dead sea observe from the earth's output

மேற்பரப்பிலிருந்து நிலத்தோற்றத்தைக்

what does the dead sea observe from the earth's output

When observing the stagnation from the earth 's output , the very low area is the Dead Sea , which is 418 meters away , and the very high area , according to the 2005 calculations , is an extensive area of 8,848 meters .

பூமியின் மேற்பரப்பிலிருந்து நிலத்தோற்றத்தைக் காணும் போது மிகவும் தாழ்வான இடம் −418 மீ ஆழத்தில் உள்ள சாக்கடல் (Dead Sea), மற்றும் 2005 ஆம் ஆண்டின் கணக்கெடுப்பின்படி மிகவும் உயரமான இடம் 8,848 மீட்டர் அளவு கொண்ட எவரெஸ்ட் சிகரம் ஆகும்.

பூமியின் மேற்பரப்பிலிருந்து நிலத்தோற்றத்தைக் காணும் போது மிகவும் தாழ்வான இடம் −418 மீ ஆழத்தில் உள்ள சாக்கடல் (Dead Sea), மற்றும் 2005 ஆம் ஆண்டின் கணக்கெடுப்பின்படி மிகவும் உயரமான இடம் 8,848 மீட்டர் அளவு கொண்ட எவரெஸ்ட் சிகரம் ஆகும்.

When observing the stagnation from the earth's output, the very low area is the Dead Sea, which is 418 meters away, and the very high area, according to the 2005 calculations, is an extensive area of 8,848 meters.

When observing the stagnation from the earth's output, the very low area is the Dead Sea, which is 418 meters away, and the very high area, according to the 2005 calculations, is an extensive area of 8,848 meters.

And if the earth is divided, then the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided.

The length of the sea is 1.4 m3.

The total output of the shell is 5.1m2. thus, the average shell will be the rate of this shell or 2.7m. the total output will be 97.5% and the other 2.5% output will be.

There is a majority of sperm, which is 68.7% of the current population.

பூமியின் நிலப்பரப்பு முழுவதும் சமமாக பரவியிருக்குமானால் நீரின் மட்டம் நிலத்தின் மீது 2.7 கி.மீ. உயர்ந்து இருக்கும்.புவியின் கடலின் மொத்த கொள்ளளவு 1.4கிமீ3. புவியின் மொத்த மேற்பரப்பு 5. 1கிமீ². எனவே, சராசரி ஆழம் இந்த இரண்டின் விகிதம் அல்லது 2.7 கி.மீ. மொத்த நீரில் 97.5% உப்பு நீராகும் மற்ற 2.5% தூய நீராகும். இதில் பெரும்பான்மையான தூயநீர், அதாவது 68.7% தற்போது பனிக்கட்டிகளாக உள்ளது.

பூமியின் நிலப்பரப்பு முழுவதும் சமமாக பரவியிருக்குமானால் நீரின் மட்டம் நிலத்தின் மீது 2.7 கி.மீ. உயர்ந்து இருக்கும்.புவியின்

கடலின் மொத்த கொள்ளளவு 1.4கிமீ3.

புவியின் மொத்த மேற்பரப்பு 5. 1கிமீ². எனவே, சராசரி ஆழம் இந்த இரண்டின் விகிதம் அல்லது 2.7 கி.மீ. மொத்த நீரில் 97.5% உப்பு நீராகும் மற்ற 2.5% தூய நீராகும்.

இதில் பெரும்பான்மையான தூயநீர், அதாவது 68.7% தற்போது பனிக்கட்டிகளாக உள்ளது.

And if the earth is divided, then the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided. The length of the sea is 1.4 m3. The total output of the shell is 5.1m2. thus, the average shell will be the rate of this shell or 2.7m. the total output will be 97.5% and the other 2.5% output will be. There is a majority of sperm, which is 68.7% of the current population.

And if the earth is divided, then the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided, and the earth will be divided.

The total output of the shell is 5.1m2. thus, the average shell will be the rate of this shell or 2.7m. the total output will be 97.5% and the other 2.5% output will be.

There is a majority of sperm, which is 68.7% of the current population.

The total volume is 3.5%. this volume is also exposed when it comes to heat events and in cold flames.

நிகழ்வுகளாலும்

தீப்பாறைகளிலிருந்தும்

வெளிப்பட்டதாகும்

Question: what is the total volume of fire volume

The total volume is 3.5%. this volume is also exposed when it comes to heat events and in cold flames.

Question: in what type of fire is the volume of water exposed

குளிர்ந்த தீப்பாறைகளிலிருந்தும்

in what type of fire is the volume of water exposed

Question: in what type of events is the volume exposed

in what type of events is the volume exposed

Question: when is the volume of water exposed

நிகழ்வுகளாலும்

Question: what percentage of total volume is exposed to fire

what percentage of total volume is exposed to fire

Question: when is the volume of fire volume exposed

நிகழ்வுகளாலும் மற்றும் குளிர்ந்த தீப்பாறைகளிலிருந்தும்

when is the volume of fire volume exposed

The total volume is 3.5 % . this volume is also exposed when it comes to heat events and in cold flames .

மொத்த நிறையில் 3.5% உப்பாலானது. இந்த உப்பானது எரிமலை நிகழ்வுகளாலும் மற்றும் குளிர்ந்த தீப்பாறைகளிலிருந்தும் வெளிப்பட்டதாகும்.

மொத்த நிறையில் 3.5% உப்பாலானது. இந்த உப்பானது எரிமலை நிகழ்வுகளாலும் மற்றும் குளிர்ந்த தீப்பாறைகளிலிருந்தும் வெளிப்பட்டதாகும்.

The total volume is 3.5%. this volume is also exposed when it comes to heat events and in cold flames.

The total volume is 3.5%. this volume is also exposed when it comes to heat events and in cold flames.

This is the light of the earth, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in it.

prelude, imagemap, introduction, atmos evolution, earth systems, reactivity, organic matters, phosphorus, oceanic processes,
photochemistry, fire, weathering, burial and tectonics, anthropogenic influence, glossary, references, quiz
OXYSPHERE
OCEANIC PROCESSESOceans cover over two-thirds of Earth's surface. Free oxygen gas first became introduced in the oceans several billion years ago as a waste product of photosynthesis. The accumulation of dissolved oxygen in the water was toxic to the early organisms and their survival depended upon their ability to develop protective tissues.
Marine photosynthesizers at the surface of the Earth's oceans were the first forms of life to successfully populate Earth. They continue to be the greatest source of gaseous oxygen today.POWERED BY THE SUNPhotosynthetic activity occurs in the uppermost regions of the water column where sunlight is sufficiently energetic to power it. This upper sunlit water is called the photic zone. It varies in depth depending upon the angle of the Sun's rays and the clarity of the water.
Summer Sunshine
During summer days, the incident angles of solar radiation are highest, causing the deepest and most energetic penetration of sunlight into the water column. Photosynthetic activity is greatest during this time and much oxygen waste gas accumulates in the water.
Thermocline prevents mixing
Surface waters expand when they heat up in the summer sunshine. This increases their buoyancy which may result in the development of a warm and stable layer at the surface. This warm water rests on top of colder water and may extend only as deep as wave action can mix warm surface water into the ocean. This warm layer acts like a lid, preventing the mixing of surface waters with colder, deeper water. Excess oxygen gas from photosynthesis builds up in this mixed layer and is subsequently released into the atmosphere.
Heating releases gases
The amount of dissolved gas that water can hold depends upon its temperature. Seawater can hold fewer dissolved gas molecules when it heats up. Oxygen (and other gases) come out of solution and enter the atmosphere as the water is heated.
The three major dissolved gases in the surface waters of the ocean are oxygen, nitrogen, and argon. The ratio that they exist dissolved in the ocean is not the same as is the ratio existing in the atmosphere. The ratio of O2:N2:Ar in the surface waters is approximately 20:36:1 [5b]. The atmospheric ratio of 21:78:1 shows that more oxygen gas dissolves in the sea than does nitrogen gas. Nitrogen gas is not as soluble as oxygen and argon, so when water releases its dissolved atmospheric gases, the air becomes relatively enriched in oxygen.
When the surface waters heat up, a slight enrichment of atmospheric oxygen occurs in the overlying air.
Winter characteristics
During winter periods, colder water absorbs more dissolved gases. As this happens, a slight depletion of oxygen from the overlying atmosphere occurs at the sea surface as oxygen gas is absorbed. The angle of sunlight during winter is lower as well; photosynthesis is greatly diminished without intense sunshine penetrating the water. With the diminished creation of oxygen gas by photosynthesizers, there is more room for the absorption of oxygen from the atmosphere.
Low sunlight angles allow cold atmospheric temperatures to predominate, especially at higher latitudes. Wintertime surface waters will be prone to sink due to an increased density from the colder temperatures. As dense surface waters sink, they transport absorbed gases along with them.
The descending surface waters are replaced by slightly less dense water from below in a mixing process called convection. This causes a mixing of surface and deeper waters and a subsequent redistribution of oxygen from the atmosphere to the deep ocean. Rising deeper water is often enriched in nutrients which is then also redistributed during winter convection. Colder regions of the ocean support larger animal populations due to the mixing of dissolved gases from above and nutrients from below [3a].
HEMISPHERIC CHARACTERISTICS OF ATMOSPHERIC GASES
The change in the levels of atmospheric oxygen over an ocean is different than it is over land because oxygen gas is soluble in seawater. The solubility creates smaller fluctuations in the levels of atmospheric oxygen over an ocean compared to the direct exchanges that land plants have with the atmosphere. Additionally, due to the time necessary for convection and diffusion processes to permit the mixing of oceanic and atmospheric gases, a slight delay exists in maximum and minimum concentrations over an ocean compared to the direct exchanges of land plants.
The surface of the Earth's Southern Hemisphere is dominated by ocean. Earth's continents are concentrated in the Northern Hemisphere. This difference is represented by the seasonal atmospheric gas levels between the two hemispheres.The following figure illustrates the effects an ocean has on the levels of two atmospheric gases: oxygen and carbon dioxide. Carbon dioxide is many times more soluble in water than oxygen and this is reflected in a smaller change in the amplitude of its atmospheric concentration. Carbon dioxide is 34 times more soluble in the ocean than oxygen. Its annual fluctuation in the Southern Hemisphere exhibits a much smaller amplitude than does its northern counterpart.
Comparing differences in atmospheric oxygen and carbon dioxide levels between hemispheres [5c].
What is initially striking about the figure is the near anti-correlation between gas curves from opposite hemispheres. The seasonal fluctuation of photosynthetic gases causes a maximum oxygen release during the Northern Hemisphere's late summer (August - September) while at the same time, oxygen is at a minimum in the Southern Hemisphere's late winter.
test your knowledge: try the oxysphere quiz for this section
prelude, imagemap, introduction, atmos evolution, earth systems, reactivity, organic matters, phosphorus, oceanic processes,
photochemistry, fire, weathering, burial and tectonics, anthropogenic influence, glossary, references, quiz
please comment to Ron Merritt Morris
rmorris2@csulb.edu

இந்த உப்பானது எரிமலை நிகழ்வுகளாலும் மற்றும் குளிர்ந்த தீப்பாறைகளிலிருந்தும் வெளிப்பட்டதாகும். வளிமண்டலத்திலுள்ள பல வாயுக்கள் பெருங்கடலில் கரைந்து அதில் வாழும் உயிரினங்களுக்கு ஆதாரமாய் உள்ளது.

இந்த உப்பானது எரிமலை நிகழ்வுகளாலும் மற்றும் குளிர்ந்த தீப்பாறைகளிலிருந்தும் வெளிப்பட்டதாகும். வளிமண்டலத்திலுள்ள பல வாயுக்கள் பெருங்கடலில் கரைந்து அதில் வாழும் உயிரினங்களுக்கு ஆதாரமாய் உள்ளது.

This is the light of the earth, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in it.

This is the light of the earth, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in the heavens, and it is revealed in it.

|
|
Sea Surface Temperature
Physical Ocean | Topography | Temperature | Salinity | Winds | Currents | Ice
Instruments aboard NASA's and NOAA's spacecrafts use their vantage point from space to collect global measurements of
the ocean's surface temperature. Each day these instruments make thousands of measurements of broad swaths of the Earth
- creating concurrent data sets of the entire planet. By developing global, detailed, and decades-long views of Sea
Surface Temperature (SST), data obtained from NASA and NOAA satellites provide the basis for the prediction of climate
change, ocean currents, and the potent El Niño-La Niña cycles.
El Niño is perhaps the best known example of the impact that changing
sea surface temperature has on our climate. Every three to seven years, this warming of surface ocean waters in the
eastern tropical Pacific brings winter droughts and deadly forest fires in Central America, Indonesia, Australia, and
southeastern Africa, and lashing rainstorms in Ecuador and Peru. El Niño
affects thousands of people worldwide, and billions of dollars in economic impact. El
Niño's "sister," La Niña, occurs less frequently and has the
opposite effect - the cooling of surface ocean waters.
But changing SST patterns have broader implications than just the El
Niño and La Niña cycles. Changes in SST are the single
most important indicator of climate change. Heat is one of the main drivers of global climate, and the ocean is a huge
reservoir of heat. The top 6.5 feet of ocean has the potential to store the equivalent amount of heat contained in the
atmosphere. The ocean has a high capacity and as ocean currents move tremendous amounts of water over vast distances,
heat is also carried or transferred over these distances. This release of heat can play a major role in climate from the
regional/basin to global scale. It is for this reason that oceans are termed the 'memory' of the Earth's climate system.
Tracking SST as a variable over long periods of time, as well as operationally, is critical for developing climate
models and improved weather forecasts.
Every day the Moderate-resolution Imaging Spectroradiometer (MODIS) measures sea surface temperature over the
entire globe with high accuracy. This false-color image shows a one-month composite for May 2001. Red and yellow
indicates warmer temperatures, green is an intermediate value, while blues and then purples are progressively colder
values.
The distribution of temperature at the sea surface tends to be zonal, that is, it is independent of longitude. Uneven
heating of the Earth by the Sun causes the warmest water to be near the equator, while the coldest water is near the poles. The
deviations from these zonal measurements are small. The anomalies of sea-surface temperature, the deviation from a long
term average, are also small, less than 1.5°C/34.7°F except in the equatorial Pacific where the deviations can
be 3°C/37.4°F. Large deviations in the Equatorial Pacific are due primarily to the El Niño-La Niña cycle.
Most weather and climate events are the result of sea and atmospheric coupling. Heat energy released from the
ocean is the dominant driver of atmospheric circulation and weather patterns. SST influences the rate of energy transfer
into the atmosphere, as evaporation increases rapidly with temperature. Knowing the temperature of the ocean
surface provides tremendous insight into short and long term weather and climate events.
Temperature as measured by the NASA Aqua satellite's Advanced Microwave Scanning Radiometer
(AMSR-E) instrument. Temperature is represented by the colors in the ocean. Orange and red indicate the necessary
27.7°C/82°F and warmer sea surface temperatures for a hurricane to form. This visualization was match-frame
rendered to another visualization showing clouds. This visualization was created in support of the Recipe for a Hurricane feature story.
Taking the Ocean's Temperature
The most commonly used instrument to measure sea-surface temperature from space is the Advanced Very High Resolution
Radiometer AVHRR. Since 1999, the Moderate-resolution Imaging Spectroradiometer
(MODIS) sensor has been collecting even more detailed measurements of surface temperature. More recently, the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) has been
collecting SST that includes areas covered by clouds. A key attribute of the AVHRR data is the length of the time
record. An AVHRR sensor has been carried on all polar-orbiting meteorological satellites operated by NOAA since Tiros-N
was launched in 1978. High quality measurements of the temperature of the ocean are now available from 1981 to the
present. This unique SST data set is now the longest satellite derived oceanographic record, providing a 25-year (and
continuing) record of global SST changes. Conversely, MODIS and records are much shorter.
Sea surface temperature data are used to help us predict
weather patterns, to track ocean currents, and to monitor El Niño and La Niña. Sea surface temperature influences the growth of phytoplankton, as
well as precipitation patterns across continents, thus indirectly influencing land vegetation. (Data from Advanced Very
High Resolution Radiometer [AVHRR])
Thermal Infrared Remote Sensing
AVHRR and MODIS instruments use radiometers to measure the amount of thermal infrared radiation given off by the
surface of the ocean. Thermal infrared remote sensing is based on the fact that everything above absolute zero
(-273°C/459°F) emits radiation in the thermal infrared region of the electromagnetic spectrum. The amount of thermal
infrared radiation given off by an object is related to its temperature (dying embers give off less radiation than a hot
fire). Thus by measuring the amount of radiation given off by the ocean we can calculate its temperature. With
instruments like radiometers, it is possible to get a picture of the thermal environment that we cannot experience with
our normal human sensors. The ability to record precise variations in infrared radiation has tremendous application in
extending our observation of many types of phenomena where minor temperature variations are significant
in understanding our environment.
Moderate-resolution Imaging Spectroradiometer (MODIS)
MODIS is sensitive to five different wavelengths, or "channels," of radiation used for measuring SST. Both night and
day, the sensor measures the thermal infrared energy escaping the atmosphere at 12 microns and then compares that
measurement to how much energy is escaping at 11 microns, allowing scientists to determine how much the atmosphere
modifies the signal so they can "correct" the data to more accurately derive SST. The MODIS sensor, because of the
increased number of channels, tells us a great deal about the influence of the atmosphere on measurements of SST.
Similar to AVHRR, MODIS also takes daily measurement of the global ocean.
Advanced Microwave Scanning Radiometer for EOS (AMSR-E)
Because AVHRR and MODIS cannot observe the ocean when the atmosphere is cloudy, NASA developed a new sensor, AMSR-E,
that is able to observe through the clouds. AMSR-E on the Aqua satellite is a passive microwave radiometer, modified
from the Advanced Earth Observing Satellite-II (ADEOS-II). Microwaves are radio waves that are able to pass through
clouds. Thus, the AMSR-E instrument can measure radiation from the ocean surface through most types of cloud cover,
supplementing infrared based measurements of SST that are restricted to cloud-free areas. However, the resolution of
AMSR-E is coarser than the thermal IR sensors. The addition of AMSR-E data will provide a significant improvement in our
ability to monitor SST and temperature controlling phenomenon.
The temperature of the world's ocean
surface provides a clear indication of the regions where hurricanes and typhoons form, since they can only form when the
sea surface temperature exceeds 27.8°C (82°F). In this visualization of AMSR-E data covering the period from
June, 2002 to September, 2003, areas with surface temperatures greater than 82°F are shown in yellow and orange,
while sea surface temperatures below 82°F are shown in blue. The region in the Atlantic from the Caribbean to the
equator only exceeds the critical temperature during late summer and early fall in the Northern Hemisphere, the period
known as "Hurricane Season." It is also possible to see the Gulf Stream, the warm river of water that parallels the east
coast of the United States before heading towards northern Europe, in this data. Around January 1, 2003, a cooler-than-
normal region of the ocean appears just to the west of Peru as part of an La
Niña and flows westward, driven by the trade winds. The waves that appear on the edges of this cooler area
are called tropical instability waves and can also be seen in the equatorial Atlantic Ocean at about the same
time.
Sea Surface Height & Temperature
Sea surface height data can also provide clues to studying the temperature of the ocean. Warm water expands raising
the sea surface height. Conversely, cold water contracts lowering the height of the sea surface. Thus, measurements of
sea surface height can provide information about the heat content of the ocean. The height can tell us how much heat is
stored in the ocean water column below its surface. Learn more about sea
surface height.
Interpreting Sea Surface Temperature Measurements
Radiation observed by AVHRR and MODIS is modified by its passage through the atmosphere. The degree to which the
signal is modified depends upon the chemistry of the overlying atmosphere. Clouds, haze, dust or smoke can interfere
with a space-based remote sensor's ability to accurately measure SST, as can greenhouse gases, like water vapor. These are
present in abundance in the tropics and strongly absorb infrared energy and re-radiate it back toward the surface.
Scientists have created several algorithms to correct the impact of these variables creating more accurate measurements
of SST.
Further, scientists analyze SST data to provide new products that have a wide variety of uses. SST data are also
distributed and processed by several organizations. These data sets are then used operationally by sponsoring agency
scientists and other organizations.
SST data is also combined with other data taken in-situ by ships and bouys. This data helps calibrate the satellite
data to create a more accurate measurement of SST.
SST data is used by many different organizations for regional studies, anomaly studies, climate and meteorological
studies, and to provide near real - time access to the data. SST data products are also widely used by the fishing
industry to track the conditions where fish are most likely to be found.
Long term averages of sea surface temperature are used to calculate the normal seas surface temperature conditions
for a specific time of year and location. Deviations from the long-term mean are called anomalies. The long-term means
are also used for studying climate change. Other data is made available in time intervals of less than a day - in some
instances within a few hours of collection. This type of data is mostly used for detecting specific features in the ocean,
such as currents and eddies.
Trends we observe
SST data is used to observe many regional phenomena around the world, including the Chesapeake Bay and the Gulf of
Mexico, the Gulf Stream, Kuroshio, the Somali Current, the Brazil Current and the East Australian Current. These
currents are associated with sharp changes in SST which can be detected using satellites. Coastal water studies are made
off the Hawaiian and Alaskan coasts. Multiple studies are also conducted off the North Atlantic.
The Gulf Stream, one of the ocean's most significant and fastest currents moves at four miles per hour. This
current of warm water, which is called the North Atlantic Drift after it turns offshore at Cape Hatteras, travels from
the Gulf of Mexico to northern European waters. The current's warm waters are responsible for the more temperate
climates experienced by Ireland, England, Scotland, and the Isles of Scily. At the beginning of the Current, in the Gulf
of Mexico, its temperature is around 27°C (80°F), but by the time it reaches northern Europe it has cooled down to
a few degrees Fahrenheit. As it cools, it gives up heat to the atmosphere, which carries the warmth to Europe.
This false-color Terra/MODIS image produced from Direct Broadcast data by the Space Science and Engineering Center at
the University of Wisconsin-Madison is made from data on Band 31. Its bright colors represent temperature data of the
water: the Gulf Stream is shown in shades of orange and yellow, which puts it near 20°C (68°F) on the scale
provided in the image. Land temperature data are not shown in this image and appear black, while white represents areas
where no data were collected (because clouds obscured the water). The colder waters off of the coasts of Virginia,
Maryland, Delaware, and New Jersey contrast sharply with the warmer waters of the Gulf Stream in this image from March
15, 2005. Credit: SSEC University of Wisconsin - Madison
Sea surface temperatures in the equatorial Pacific affect precipitation (and therefore plant growth) over much of the
North American continent. Warmer-than-normal water in the central and western equatorial Pacific, creates higher precipitation
in southern and central North America. Conversely, cold water temperatures in the Pacific
lead to a decrease in precipitation over northern North America.
SST may also affect one of the world's key large-scale atmospheric circulations - the circulation that regulates the
intensity and breaking of rainfall associated with the South Asian and Australian monsoons.
Projects are underway that combine data from multiple satellite systems to produce a robust set of sea surface data
for assimilation into ocean forecasting models of the waters around Europe and also the entire Atlantic Ocean. The Global
Ocean Data Assimilation Experiment, GODAE, is assimilating sea-surface temperature data, altimeter data, scatterometer data, and
drifter data into coupled ocean/atmosphere numerical models to produce forecasts of ocean currents and temperatures up to 30 days
in advance everyehwere in the ocean.
Future
Finally, projects are also being conducted to combine SST data from various sensors to create the highest quality SST.
These projects will create a new generation of multi-sensor, high-resolution SST products. An example of such a project is
the GODAE High Resolution Sea Surface Temperature Pilot Project (GHRSST-PP).
SST data are important to the development and testing of a new generation of computer models in which the interacting
processes of the land, the atmosphere, and the oceans are coupled. The measurements are widely used in the creation of more
accurate weather forecasts and increasingly it is seen as a key indicator of
climate change. It is anticipated that projects like GHRSST will provide even higher quality data sets for such things as
hurricane forecasting.
Projects like GHRSST lay the groundwork for future cooperations, between NASA and NOAA, as well as internationally. Such
cooperations will lead to major innovations in how data is distributed in near real-time, searched and stored. Plans
include a joint NASA/NOAA effort to provide users with an interface for accessing both near
real-time and historical data for climate studies. Future technologies should allow managers, decision makers, and modelers
to search and access data in near real time for specified areas of interest. Additionally, the merging of SST data from
different sensors will provide high resolution SST data suitable for coastal studies and management.

Throposphere (Troposphere) is the surface of the earth.

It is and

As a result of the weather change, it will be 8 km in the streets and 17 km in the first earthquake.

மாறுபாட்டின்

துருவங்களில்

பூமத்தியரேகையில்

Question: what is the name of the surface of the earth

Throposphere (Troposphere) is the surface of the earth.

It is and

As a result of the weather change, it will be 8 km in the streets and 17 km in the first earthquake.

what is the name of the surface of the earth

Question: how far is the troposphere in the streets

It is and

how far is the troposphere in the streets

Question: how far was the throposphere in the first earthquake

It is and

how far was the throposphere in the first earthquake

Question: how many kilometers is the throposphere in the first earthquake

It is and

how many kilometers is the throposphere in the first earthquake

Question: what is the surface of the earth called

It is and

Question: how many kilometers is the throposphere in the streets

It is and

how many kilometers is the throposphere in the streets

Question: what is the troposphere of the earth

உயரமானது பூமியின்

It is and

Throposphere ( Troposphere ) is the surface of the earth .

As a result of the weather change , it will be 8 km in the streets and 17 km in the first earthquake .

அடிவளிமண்டல (Troposphere) உயரமானது பூமியின் கிடைமட்ட பரப்பை பொறுத்து மாறும். தட்பவெப்ப மற்றும் காலநிலை மாறுபாட்டின் காரணமாக இது துருவங்களில் 8 கி.மீ. முதல் பூமத்தியரேகையில் 17 கி.மீ. வரை இருக்கும்.

அடிவளிமண்டல (Troposphere) உயரமானது பூமியின் கிடைமட்ட பரப்பை பொறுத்து மாறும்.

தட்பவெப்ப மற்றும்

காலநிலை மாறுபாட்டின் காரணமாக இது துருவங்களில் 8 கி.மீ. முதல் பூமத்தியரேகையில் 17 கி.மீ. வரை இருக்கும்.

Throposphere (Troposphere) is the surface of the earth. It is and As a result of the weather change, it will be 8 km in the streets and 17 km in the first earthquake.

Throposphere (Troposphere) is the surface of the earth.

As a result of the weather change, it will be 8 km in the streets and 17 km in the first earthquake.

2.7 Millions of years ago occurred solar lighting initially creates the current neutrogen-oxygen lighting mountain. This variable creates the growth and image of the sun-served beings, the time of the sun, the time of the sun, the time of the sun, the time of the sun, the time of the sun, the time of the sun, the time of the sun, and the time of the sun.

There are many different types of foods that can be found in the water, such as water, water, water, and other foods that can be found in the water.

The main value is developed. Finally, the temperature change of the specified wind is referred to as the greenhouse change (Greenhouse Effect): This means that the outer wind hazard from the state minimizes the lowest temperatures in the wind and thus increases the temperature of the wind.

2.7 பில்லியன் ஆண்டுகளுக்கு முன்னர் ஏற்பட்ட பிராணவாயு ஒளிச்சேர்க்கை முதன்முதலில் தற்போதுள்ள நைட்ரஜன் - ஆக்சிஜன் வளி மண்டலத்தை உருவாக்கியது. இந்த மாற்றமானது வளி சார்ந்த உயிரினங்கள் வளர்ச்சி மற்றும் ஓசோன் படலத்தையும் உருவாக்கியதோடு, புவியின் காந்தபுலம் புற ஊதாக் கதிர்கள் சூரியனின் கதிர்வீச்சு ஆகியவற்றை தடுத்து, புவியில் உயிரினங்கள் வாழ வழிசெய்கிறது.

புவியில் உயிரினங்கள் வாழ்வதற்கு தேவையான நீராவி பரிமாற்றம், வாயுக்கள், சிறிய விண்கற்களை புவியை தாக்கும்முன் எரியசெய்தல் மற்றும் மிதமான வெப்பநிலை போன்றவற்றை அளிப்பதில் வளி மண்டலம்

முக்கியப் பங்கு வகிக்கிறது. இறுதியாக குறிப்பிட்ட வளிமண்டல வெப்பநிலை மாற்றத்தை கிரீன் ஹவுஸ் மாற்றம் என குறிப்பிடுவர் (Greenhouse Effect): இது நிலத்தில் இருந்து வெளிவரும் வெப்ப ஆற்றலை வளிமண்டலத்தில் உள்ள சிறிதளவிலான மூலக்கூறுகள் சிறைப்படுத்தி அதன் மூலம் வளி மண்டலத்தின் சராசரி வெப்பத்தை உயர்த்துவதை குறிக்கும்.

2.7 Millions of years ago occurred solar lighting initially creates the current neutrogen-oxygen lighting mountain. This variable creates the growth and image of the sun-served beings, the time of the sun, the time of the sun, the time of the sun, the time of the sun, the time of the sun, the time of the sun, the time of the sun, and the time of the sun. There are many different types of foods that can be found in the water, such as water, water, water, and other foods that can be found in the water. The main value is developed. Finally, the temperature change of the specified wind is referred to as the greenhouse change (Greenhouse Effect): This means that the outer wind hazard from the state minimizes the lowest temperatures in the wind and thus increases the temperature of the wind.

2.7 Millions of years ago occurred solar lighting initially creates the current neutrogen-oxygen lighting mountain. This variable creates the growth and image of the sun-served beings, the time of the sun, the time of the sun, the time of the sun, the time of the sun, the time of the sun, the time of the sun, the time of the sun, and the time of the sun.

There are many different types of foods that can be found in the water, such as water, water, water, and other foods that can be found in the water.

The main value is developed. Finally, the temperature change of the specified wind is referred to as the greenhouse change (Greenhouse Effect): This means that the outer wind hazard from the state minimizes the lowest temperatures in the wind and thus increases the temperature of the wind.

The heat power that comes from the sun and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth.

Earth is not the only planet with a variety of weather conditions. Every planet in the solar system except Mercury and perhaps Pluto has enough of an atmosphere to support weather systems. In addition, Titan, a moon of the planet Saturn, has such an atmosphere. Pluto is so far away that little is known about its atmosphere. The remainder of this article discusses the weather on Earth.
The weather affects our lives every day. For example, it can have an impact on what type of clothing we wear and how we spend our free time. Weather also affects agriculture, transportation, and industry. Freezing temperatures can damage citrus crops in Florida or Spain, causing a rise in the price of oranges at the grocery store. Winter snows often create hazardous driving conditions. Thick fog may slow traffic on the roads and cause delays at airports. Our use of air conditioning during heat waves and heating during cold weather means that utility companies must supply more power at those times. Severe weather, such as tornadoes, hurricanes, and blizzards, can damage property and take lives.
Because of weather's importance, meteorologists (scientists who study the atmosphere and the weather) have developed ways to forecast weather conditions. Forecasts for the next 12 to 24 hours are correct more than 80 percent of the time. Long-range forecasts for the next week or month are less accurate. These forecasts indicate general trends, such as whether or not temperatures are expected to be warmer or colder than normal.
Closely related to weather is climate. Climate is the weather of a place averaged over a length of time. Scientists determine a region's climate by examining its vegetation, average monthly and annual temperature, and average monthly and annual precipitation. Earth's surface is a patchwork of climate zones. For example, in various parts of Earth, we find deserts; tropical rain forests; prairies; forests of cone-bearing trees; frozen, treeless plains; and coverings of glacial ice. Unlike changes in the weather, which can occur in minutes, climate changes generally take many years.
This article discusses Weather (What causes weather) (Weather systems) (Measuring the weather) (Weather forecasting) (Reporting the weather) (How people affect the weather) (Careers in weather).
What causes weather
Weather takes place in the atmosphere, the layer of air that surrounds Earth. Air is a mixture of gases and tiny suspended particles.
The most plentiful gas is nitrogen, which accounts for about 78 percent of the air we breathe. The second most plentiful gas is oxygen, at 21 percent. The remaining 1 percent consists of a variety of gases. In spite of their low concentrations, some of these gases play vital roles. For example, the atmosphere contains little water vapor -- an invisible gas produced when water evaporates. Yet, without water vapor there would be no clouds, no rain, no snow, and no plants or animals.
Most of the tiny particles floating in the atmosphere are too small to be visible. They are solid or liquid and come from a number of sources, such as the wind erosion of soil, volcanic eruptions, and the release of pollutants by smokestacks and automobile tailpipes.
Most weather occurs in the lowest portion of the atmosphere, called the troposphere. The troposphere extends from Earth's surface up to an altitude of about 6 to 12 miles (10 to 19 kilometers). Three key factors that determine the weather in the troposphere are air temperature, air pressure, and humidity.
Air temperature is a measure of the energy of motion of the air's gas molecules. The factors most responsible for the heating and cooling of the atmosphere are radiation arriving from the sun and radiation flowing from Earth.
The sun continually sends energy into space as electromagnetic radiation. One kind of solar radiation is visible light. The other forms of solar electromagnetic radiation are invisible to human beings. They include infrared (heat) rays and ultraviolet rays. About 30 percent of the solar electromagnetic radiation that reaches the atmosphere is reflected back into space, mostly by clouds. The atmosphere and Earth's surface absorb the remaining 70 percent, becoming warmer.
The warmed Earth cools by radiating infrared rays. Some of this radiation travels directly into space. The atmosphere absorbs almost all the remainder as it streams off the surface of the planet. This absorption of radiation, known as the greenhouse effect, makes the air near Earth's surface about 59 Fahrenheit degrees (33 Celsius degrees) warmer than it would be otherwise.
The atmosphere also sheds heat energy by radiating infrared rays. Some of this infrared radiation flows down to the surface, while the remainder travels out into space.
Air temperature generally varies from day to night and from season to season because of changes in the amount of radiation heating Earth's atmosphere. For example, days usually are warmer than nights because Earth receives the heating rays of the sun only during the day. At night, infrared radiation from the planet streams off into space, and the air temperature drops.
Air temperature also changes with the seasons. Except near the equator, where temperatures remain fairly constant the year around, summers are warmer than winters. In the summer, the sun is higher in the sky, and days are longer. When the sun is higher above the horizon, the intensity of the sunlight striking Earth's surface increases. More hours of sunlight in summer also mean more solar heating.
Altitude also affects air temperature. Within the troposphere, the air temperature generally drops 3.5 Fahrenheit degrees per 1,000 feet of elevation (6.5 Celsius degrees per 1,000 meters of elevation). Thus, it is usually colder on top of a mountain than in the surrounding lowlands.
Air pressure is the weight per unit of area of a column of air that reaches to the top of the atmosphere. Air pressure always decreases with increasing altitude because as you move higher there is less and less air above you. Air pressure is, on average, highest at sea level and drops to about half its sea-level value at an average altitude of about 18,000 feet (5,500 meters).
Air pressure also changes from place to place across Earth's surface. Part of this change is due to differences in land elevation. Most of the remainder is caused by changes in air temperature. Cold air is relatively dense -- that is, it has more air molecules per unit volume -- and so it exerts relatively high pressure. Warm air is less dense and exerts relatively low pressure.
Regions where air pressure is relatively high usually experience fair weather, while regions where air pressure is relatively low experience cloudy, stormy weather. Generally, the weather stays fair or improves if air pressure rises. If the air pressure falls steadily, however, the weather may turn cloudy and rainy or snowy.
Air moves from areas where the air pressure is relatively high toward areas where the air pressure is relatively low. This movement of air is what we call wind.
Humidity is a measure of the amount of water vapor in the air. There is an upper limit to this amount. Air that contains its maximum amount of water vapor is described as saturated. The amount of water vapor the air can hold increases as the air temperature rises and decreases as the temperature falls. Thus, saturated warm air has more water vapor than saturated cold air.
Weather reports commonly describe the amount of water vapor in the air in terms of the relative humidity. Relative humidity compares the amount of water vapor in the air with the amount of water vapor at saturation. It is expressed as a percentage. If the relative humidity is 50 percent, the amount of water vapor in the air is half of what it would be if the air were saturated. Lowering the air temperature increases the relative humidity.
If the relative humidity is 100 percent, the air is saturated. When air becomes saturated, water vapor begins to condense into droplets of water. Condensation is the opposite of evaporation. It is a change from a gas to a liquid. If the air is cold enough, at saturation the water vapor develops into tiny ice crystals.
If condensation occurs on a cold surface such as the surface of an automobile window at night, dew or frost forms. Dew and frost do not fall from the sky like rain or snow. Rather, they form when air in contact with a relatively cold surface is chilled to saturation. The same process occurs when small drops of water appear on the outside of a cold soft-drink can on a hot summer day. The temperature to which air must be cooled to reach saturation and produce dew is known as the dew point.
When saturation occurs within the atmosphere, water vapor condenses into droplets (or develops into tiny ice crystals) that form clouds. A cloud that is in contact with Earth's surface is known as fog. Most clouds occur within the troposphere. Because air temperature drops with increasing altitude within the troposphere, high clouds are extremely cold and consist mostly of ice crystals. The crystals give these clouds a fuzzy appearance. Low clouds are warmer and generally are composed of droplets. These clouds appear to have sharper edges.
Clouds usually form where air moves upward. As air ascends, it encounters lower and lower pressure. Air responds to lower pressure by expanding. Whenever gases expand, they cool. As air cools, its relative humidity increases until it reaches saturation and clouds form.
Where air moves downward, clouds usually do not develop. Descending air is compressed, it warms up, and its relative humidity decreases. Saturation is not possible, and so clouds do not form. Weather systems
Meteorologists classify weather systems according to their size and how long they last. The two largest and longest-lasting types of systems are planetary-scale systems and synoptic-scale systems. Planetary-scale systems are the belts of winds that circle the globe and may blow in the same direction for weeks at a time. Synoptic-scale systems cover a portion of a continent or ocean and last up to a week or so. The term synoptic comes from a Greek word meaning a general view.
A supercell thunderstorm is a violent storm dominated by a single gigantic cell -- a weather system made up of storm clouds and the winds associated with them. Rain and hail may fall for hours. Image credit: National Center for Atmospheric Research/University Corporation for Atmospheric Research/National Science Foundation
Planetary-scale systems
Suppose that Earth did not rotate and that the noon sun was always directly above the equator. Air temperatures would be highest at the equator and decrease toward the poles. Cold air is denser than warm air. Thus, air pressure would be higher at the poles and lower at the equator. Because air moves from areas of high pressure to areas of low pressure, cold air would sweep toward the equator, where it would push the warm air upward. In the upper atmosphere, the warm air would move toward the poles, cool, and sink over the poles. Thus, the planetary-scale circulation of wind would consist of two huge cells, one in each hemisphere.
The real Earth rotates
Rotation of Earth on its axis causes winds that blow long distances -- thousands of miles or kilometers -- to shift direction gradually. This shift is known as the Coriolis effect, which causes winds in the Northern Hemisphere to shift to the right and winds in the Southern Hemisphere to shift to the left. In the Northern Hemisphere, for example, winds blowing southward shift to the west. Winds blowing northward shift to the east.
Rotation of the planet also causes winds near Earth's surface to split into three belts in each hemisphere. These three belts are (1) the trade winds, which blow near the equator, between 30 degrees north latitude and 30 degrees south latitude; (2) the westerlies (winds from the west), which blow in the middle latitudes between 30 degrees and 60 degrees north and south of the equator; and (3) the polar winds, which blow in the Arctic and Antarctic, from 60 degrees latitude toward the poles.
Trade winds north of the equator blow from the northeast. South of the equator, they blow from the southeast. The trade winds of the two hemispheres meet near the equator, causing air to rise. Rising air cools, and its relative humidity therefore increases. Thus, a band of cloudy, rainy weather circles the globe near the equator.
Westerlies blow from the southwest in the Northern Hemisphere and from the northwest in the Southern Hemisphere. Westerlies and trade winds blow away from the 30 degrees latitude belt. Over broad regions centered at 30 degrees latitude, surface winds are light or calm, and air slowly descends. Air warms as it descends, and its relative humidity decreases, making clouds and precipitation unlikely. As a result, fair, dry weather characterizes much of the 30 degrees latitude belt.
Polar winds are easterlies (winds from the east). They blow from the northeast in the Arctic and from the southeast in the Antarctic. In the Northern Hemisphere, the boundary between the cold polar easterlies and the mild westerlies is known as the polar front. A front is a narrow zone of transition, usually between a mass of cold air and a mass of warm air. Storms develop and move along the polar front, bringing cloudiness, rain, or snow.
Important seasonal changes take place in Earth's wind patterns. Wind belts shift toward the poles in spring and toward the equator in fall. For example, during the fall, the polar front in the Northern Hemisphere often moves from Canada down to the continental United States.
Planetary-scale winds control the direction of movement of smaller-scale weather systems. For example, in the tropics, trade winds generally steer hurricanes and other weather systems from east to west. In middle latitudes, westerlies move weather systems from west to east. The westerlies are particularly vigorous near the top of the troposphere and just over the polar front. This corridor of exceptionally strong winds is known as a jet stream. The jet stream of the polar front supplies energy to developing storms and then moves them rapidly along the front.
Synoptic-scale systems include air masses, fronts, lows, and highs. The movement of these systems causes the day-to-day changes in the weather of Europe, the continental United States, and other regions in the middle latitudes.
Air masses
An air mass is a huge volume of air covering thousands of square miles or kilometers that is relatively uniform in temperature and humidity. The properties of an air mass depend on where it forms. Air masses that develop at high latitudes are colder than air masses that form over low latitudes. Air masses that form over the ocean are relatively humid, and those that form over land are relatively dry. The four basic types of air masses are (1) cold and dry, (2) cold and humid, (3) warm and dry, and (4) warm and humid.
Across North America, warm air masses move north and northeastward, and cold air masses move south and southeastward. Maritime polar air, which is cool and humid, forms over the North Pacific and North Atlantic. This air mass brings low clouds and precipitation to the Pacific Northwest, New England, and eastern Canada. Continental polar air, which is dry and cold in winter and dry and mild in summer, forms in north-central Canada. Arctic air, which is dry and much colder than continental polar air, forms over the snow-covered regions north of about 60¡ latitude in the Northern Hemisphere. The movement of Arctic air to the south causes the bone-numbing cold waves that sweep across the Great Plains and Northeast in winter.
Most of the maritime tropical air that invades North America originates over the Gulf of Mexico and the tropical Atlantic. This warm, humid air mass brings oppressive summer heat waves to areas east of the Rocky Mountains. Continental tropical air forms over the deserts of Mexico and the southwest United States. In summer, this hot, dry air mass surges over Texas and other parts of the American Southwest.
As an air mass travels from place to place, its temperature and humidity can change. For example, air over the Pacific Ocean west of North America is mild and humid. If that air mass moves eastward, it is forced up the slopes of the coastal mountain ranges. Air temperature drops, the relative humidity increases to saturation, clouds form, and rain or snow develops. As the air travels down the opposite slopes of the mountain ranges, the air temperature rises, the relative humidity decreases, and clouds thin out or vanish.
This process repeats with each mountain range the air mass encounters as it moves eastward. By the time it reaches the Western Plains, the air mass has become considerably drier and milder. This modified air mass, known as Pacific air, brings mild, dry weather to much of the central and eastern regions of the United States and Canada.
Fronts form where air masses meet. A front is a narrow zone of transition between air masses that differ in temperature or humidity. In most cases, the air masses differ in temperature, so that the fronts are either warm or cold.
A warm front is the leading edge of an advancing warm air mass. Warm air is less dense than cold air, so warm air advances by riding up and over the retreating cold air. As the warm air ascends, its temperature drops, relative humidity increases, and clouds and perhaps precipitation form. In North America, clouds can extend hundreds of miles or kilometers to the north and northwest of a warm front. Rain or snow is usually light to moderate and may last 12 to 24 hours or longer.
A cold front is the leading edge of an advancing cold air mass. Cold air is denser than warm air, so that cold air advances by moving under and pushing up the retreating warm air. As warm air ascends, its temperature falls, relative humidity rises, and clouds and often precipitation develop. Clouds associated with a cold front typically form a narrow band along the front. Rain or snow falls in brief showers. If the cold front is fast-moving and well-defined by considerable temperature contrast across the front, thunderstorms are likely. Some of these thunderstorms could become severe and produce hail, torrential rains, or strong winds. Tornadoes also may develop from severe thunderstorms.
A front that stalls is known as a stationary front. The weather along a stationary front often consists of considerable cloudiness and light rain or snow.
Cold fronts move faster than warm fronts, so a cold front may catch up to and merge with a warm front. The warm air is lifted off Earth's surface, and the merged front is known as an occluded front. An occluded front sometimes moves very slowly and causes several days of considerable cloudiness and light precipitation.
Lows are areas of relatively low air pressure. The winds in a low pressure system bring contrasting air masses together to form fronts. For this reason, lows are sometimes described as the chief weather-makers of regions in the middle latitudes. Scientists use the term cyclone to refer to a synoptic-scale low-pressure area. They also use the term to mean a hurricane in some parts of the world.
Viewed from above in the Northern Hemisphere, surface winds in a low-pressure area blow in a counterclockwise and inward direction. Surface winds converging in the low cause air to rise, cool, and reach saturation. Clouds and precipitation usually develop. Air ascends mostly along fronts that develop as winds in the low bring cold and warm air masses together.
Lows generally travel from southwest to northeast across North America and may complete a journey from Colorado to New England in three or four days. As a rule, temperatures are lower to the left (north) of the path followed by the low-pressure area and higher to the right (south). In winter, the heaviest snows usually fall about 90 to 150 miles (150 to 250 kilometers) to the north and west of the moving low-pressure area.
Highs, also known as anticyclones, are areas of relatively high air pressure. A high, which brings fair weather, often follows in the wake of a low. Viewed from above in the Northern Hemisphere, surface winds in a high blow in a clockwise and outward direction. As winds blow out and away from a high, air descends near the center of the system. Descending air warms, and the relative humidity decreases.
Highs are either warm or cold. Warm highs form south of the polar front and are characterized by high temperatures and low relative humidities. Such highs are massive weather systems that extend from Earth's surface to the top of the troposphere. In the summer, a warm high sometimes stalls over North America. If the high remains stationary for several weeks, it creates a drought.
Cold highs form north of the polar front. They are shallow masses of cold, dry air that develop mostly in the winter over the snow-covered regions of northern Canada, Alaska, and Siberia. As cold highs move southeastward over Canada and into the continental United States, they bring fair but cold weather.
Mesoscale and microscale systems result from the development and movement of synoptic and planetary-scale systems. Mesoscale systems, which may last an hour or less and affect only part of a city, include thunderstorms and sea breezes. A tornado is an example of a microscale system, the smallest and briefest of significant weather systems.
Measuring the weather
Because no single country can constantly measure and report on conditions in every part of the atmosphere, the world's nations must cooperate to monitor the weather effectively. To this end, they founded the International Meteorological Organization in 1873, renaming it the World Meteorological Organization (WMO) in 1950. Members of the WMO participate in the worldwide observation of the atmosphere and in the exchange of weather data and forecasts. Weather observations come from many different sources, including land-based observation stations, radar systems, weather balloons, airplanes, ships, and satellites.
Land-based observation stations. About 10,000 land-based weather stations -- also known as surface stations -- monitor the weather worldwide. In the United States, the National Weather Service coordinates weather observations at about 1,000 land-based stations with information obtained from about 10,000 volunteer weather observers. The Atmospheric Environment Service of Canada operates a similar observation network.
Observation stations use a variety of instruments to monitor the state of the atmosphere. An electronic thermometer checks air temperature and registers the highest and lowest temperature of the day. A hygrometer measures the amount of water vapor in the air. A barometer shows the air pressure. A weather vane indicates the direction of the wind, and an anemometer monitors wind speed. Rain gauges measure rainfall or snowfall. For more information, see the separate articles on weather instruments in World Book.
Weather radar
Some observation stations use radar to track storms. Weather radar can operate in either a reflectivity mode or a velocity mode.
In the reflectivity mode, weather radar locates areas of rain or snow. The system sends out a radar signal, which consists of microwave energy pulses. If the radar signal encounters rain, snow, or hail, the falling precipitation reflects some of that signal back to the radar. The reflected radar signal, called a radar echo, appears as a blotch on a television-type screen. As the radar rotates, it generates a map of radar echoes that represents the pattern of precipitation surrounding the radar. In the reflectivity mode, weather radar can detect precipitation more than 250 miles (400 kilometers) away.
In the velocity mode, weather radar determines the circulation of air from the motion of raindrops, snowflakes, or dust particles. This radar is also known as Doppler radar because it uses the Doppler effect to calculate how the air in a weather system is moving.
The Doppler effect is the change in frequency of sound or radiation waves caused by the motion of the source of the waves relative to their observer. For example, the pitch (frequency) of a train whistle seems higher as a train approaches and lower as the train moves away. Similarly, as raindrops, snowflakes, or dust particles move through the atmosphere, the radar signals they reflect change in frequency. The radar monitors these frequency changes and then uses them to calculate the speed at which the drops, flakes, or particles are advancing or receding.
A Doppler radar image is color-coded to indicate the speed and direction at which rain clouds and other masses of air are moving. Doppler radar can provide warning of severe weather. Image credit: National Center for Atmospheric Research/University Corporation for Atmospheric Research/National Science Foundation
Weather balloons, airplanes, and ships
To obtain information on the state of the atmosphere above Earth's surface, meteorologists routinely use an instrument package called a radiosonde. The radiosonde, which is carried aloft by a weather balloon, measures changes in temperature, pressure, and humidity. A small radio transmitter beams these data back to a weather station, where they are recorded by computer. At an altitude of about 19 miles (30 kilometers), the balloon bursts, and a parachute carries the instrument package back to Earth's surface.
Meteorologists use a special antenna to track a radiosonde and thereby measure wind speed and direction at different altitudes within the atmosphere. Such an observation is known as a rawinsonde. Radiosonde and rawinsonde observations are made every 12 hours.
Meteorologists sometimes use a dropwindsonde to obtain atmospheric measurements over the oceans. A dropwindsonde is a radiosonde attached to a parachute and dropped from an aircraft. As the instrument package falls toward the sea, it radios back to the aircraft measurements of temperature, pressure, and humidity.
Ships also report on weather conditions at sea. Some launch weather balloons, and others release special ocean buoys that record and transmit information about weather at sea level.
Weather satellites play a major role in worldwide weather observation. They monitor clouds associated with weather systems, track hurricanes and other severe weather systems, measure winds in the upper atmosphere, and obtain temperature measurements.
A hurricane approaches the Bahamas and Florida in this image taken from a weather satellite in orbit about 22,300 miles (35,900 kilometers) above the earth. Only satellites can provide images of the weather over vast expanses of the earth's surface, making satellites an essential part of modern storm detection. Image credit: National Oceanic and Atmospheric Administration
Sensors aboard weather satellites detect two types of radiation signals coming from the planet. One signal consists of reflected sunlight. These satellite images, which resemble black-and-white photographs of the planet, reveal cloud patterns.
The second signal recorded by weather satellites is infrared radiation (IR). The intensity of the infrared radiation emitted by an object depends on the object's temperature. For example, low clouds and fog, which are relatively warm objects, give off more intense infrared radiation than do high clouds, which are relatively cool. Thus, an IR image reveals not only cloud patterns but also cloud temperatures. Weather satellites can record IR images at any time -- day or night -- because objects continually emit infrared radiation.
There are two main types of weather satellites -- geostationary and polar-orbiting. A geostationary satellite orbits about 22,300 miles (35,900 kilometers) above the equator and travels eastward at the same rate as Earth rotates. Thus, a geostationary satellite remains above the same point on the equator. Because geostationary satellites orbit at such a high altitude, they can record images that cover a wide area. For example, two of them cover most of the United States and Canada. Most satellite images shown on televised weather reports come from this type of satellite.
A polar-orbiting satellite follows a north-south path that takes it over the polar regions. Because the satellite does not rotate east as Earth does, the rotation of Earth causes the satellite to pass over different areas of Earth each orbit. Polar-orbiting satellites travel at a much lower orbit than geostationary satellites, and so they record more detailed images. Weather forecasting
After meteorologists have gathered weather data from around the world, they can try to predict the development and movement of future weather systems. To forecast the weather, meteorologists use such tools as weather maps and mathematical models.
Weather maps
Meteorologists use weather observation data to create weather maps that represent the state of the atmosphere at a particular time. To capture the three-dimensional nature of weather, they draw maps for conditions at Earth's surface and at various levels within the atmosphere. By examining a sequence of weather maps, forecasters can determine how the weather changes through time and then make predictions about the future state of the atmosphere.
Mathematical models
Since the mid-1950's, weather forecasters have used mathematical models of the atmosphere, processed by computers, to improve the accuracy of their predictions. A mathematical model of the atmosphere consists of a set of equations intended to approximate the atmospheric processes that drive the development and movement of weather systems. Mathematical models are based on scientific laws, and through the years scientists have developed increasingly sophisticated models. Improvements in computer technology have greatly enhanced meteorologists' ability to use mathematical models effectively because computers can process enormous amounts of observation data and perform a multitude of calculations extremely rapidly.
A mathematical model begins with the current state of the atmosphere, as determined by the most recent weather observations. The model uses these data to predict the state of the atmosphere for a specific time interval -- for example, the next 10 minutes. Using this predicted state as a new starting point, the model then forecasts the state of the atmosphere for another 10-minute period. This process repeats over and over again until the model produces short-range weather forecasts for the next 12, 24, 36, and 48 hours.
The accuracy of weather forecasts generated by mathematical models declines steadily over time for two main reasons. First, the weather observation data initially fed into the model can never provide a complete picture of the present state of the atmosphere. Not all the data are reliable, due to both technical and human error, and data are missing from vast stretches of the atmosphere over the oceans. Second, mathematical models of the atmosphere are only approximations of the way the atmosphere actually works, and errors in the models tend to grow with each repetition.
Meteorologists understand the limitations of mathematical models. They base their forecasts on observations of how the weather has changed over the past several days and on their understanding of atmospheric processes. Experience and even intuition play important roles, along with the cautious interpretation of the output of mathematical models.
Meteorologists also use mathematical models to produce long-range weather forecasts, such as 6- to 10-day forecasts and monthly (30-day) and seasonal (90-day) outlooks. Long-range forecasts and outlooks typically are less accurate than short-range forecasts, but they can provide an indication of general trends, such as whether conditions will be wetter or drier than normal. Reporting the weather
The National Weather Service of the United States and the Atmospheric Environment Service of Canada issue weather forecasts, watches, warnings, and advisories to the public through regional forecast offices. The public accesses this information through radio and television broadcasts, newspapers, and the Internet.
When hazardous weather threatens, forecasters issue outlooks, watches, warnings, and advisories. An outlook provides advance notice of a general weather trend. For example, the outlook for spring flooding due to expected snowmelt is usually available many weeks in advance. A weather watch is issued when hazardous weather is possible based on current or predicted atmospheric conditions. A weather warning applies when hazardous weather is taking place nearby. Watches and warnings are issued for severe thunderstorms, tornadoes, floods, hurricanes, and winter storms, such as blizzards and ice storms.
Weather advisories refer to expected weather hazards that are less serious than those covered by a warning. An example is a winter weather advisory.
Weather advisories are also issued for low wind chill temperatures and for a high heat index. Wind chill is a measure of the cooling power of a combination of low air temperature and strong winds. Even if the air temperature remains constant, the human body loses increasing amounts of heat to the environment as wind speed increases. At low wind chill temperatures, people need to take special precautions to prevent frostbite (the freezing of skin tissue) and hypothermia (a dangerous drop in body temperature).
Heat index is a measure of the stress produced by a combination of high air temperature and high relative humidity. During excessively hot and muggy weather, the human body may not be able to release sufficient heat to prevent hyperthermia (a dangerous rise in body temperature). High humidity reduces the rate at which perspiration evaporates from the skin's surface. The cooling that accompanies this evaporation represents one of the body's main ways to release heat.
Private weather forecasters provide weather information tailored to a special need. For example, prior to pouring concrete, a building contractor may consult a private forecaster to find out the probability of rainfall during specific hours of the day. Department stores may hire a private forecaster to advise them of prospects for hot summer weather to ensure the stores have enough air conditioners and fans in stock.
How people affect the weather
Human activities affect the weather both intentionally and unintentionally. For example, the construction of cities creates areas that are drier and warmer than the surrounding countryside. Cities are drier because they have storm sewer systems that quickly carry off rainwater and snowmelt.
Cities are warmer for several reasons. The use of storm drainage systems means that less solar radiation is used to evaporate water and more is used to heat the city surfaces and air. The brick, asphalt, and concrete surfaces of city buildings, sidewalks, and streets readily transmit the heat they absorb and so raise urban air temperatures even more. In addition, cities themselves generate heat from a number of sources, including motor vehicles and heating and air conditioning systems.
Large urban areas also affect the weather in the areas downwind of them. Smokestacks and automobile tailpipes in cities emit water vapor and tiny particles that stimulate the formation of clouds. Heat energy rising from a city also spurs the growth of clouds. Thus, the weather downwind from many large urban areas is cloudier and rainier than the weather upwind from those same areas.
Urban and industrial areas also produce air pollutants, such as carbon monoxide, nitrogen oxides, and hydrocarbons. Although improved controls on factories and motor vehicles have reduced considerably the amount of these gases released into the atmosphere, air quality problems persist. For example, many large cities still have problems with smog -- a mixture of gases and tiny particles that reduces visibility and poses serious health hazards.
Smog and other air pollution problems are particularly serious in areas where winds are light and a temperature inversion occurs in the lower atmosphere. In a temperature inversion, warm air overlies cold air, so that the air temperature rises with increasing altitude, which is the opposite of the usual situation in the troposphere. Under such circumstances, smokestack and tailpipe emissions do not rise and disperse, and so emissions may build up to unhealthy concentrations.
From time to time, scientists have tried to alter the weather. Most of these efforts -- including attempts to modify hurricanes, suppress hailstorms, and clear fog -- have not worked. Today, scientists focus their weather modification efforts primarily on cloud seeding, an attempt to stimulate the natural precipitation-forming process.
Most clouds do not produce rain or snow. This is because few clouds have just the right combination of tiny ice crystals and supercooled water droplets (droplets that remain liquid even at subfreezing temperatures). In such clouds, ice crystals grow at the expense of water droplets and eventually become snow crystals. If the temperature is below freezing all the way to Earth's surface, precipitation falls as snow. If the air temperature is above freezing, the snow crystals melt into raindrops.
Careers in weather
High school students interested in meteorology as a career should take college-preparatory classes, including courses in mathematics, computer science, physics, and chemistry. Most entry-level jobs in meteorology require at least a bachelor's degree, and many require a master's degree. A limited number of U.S. and Canadian colleges and universities offer degrees in meteorology, and the U.S. armed forces offer meteorological training as well.
Meteorologists specialize in a number of different areas. For example, research meteorologists study some subfield of meteorology, such as tropical weather systems. Regional forecasters prepare weather forecasts for portions of one or more states or provinces. Consulting meteorologists provide weather information tailored for specific industrial, business, or government needs. Broadcast meteorologists have skills in both meteorology and television or radio broadcasting. This type of meteorologist informs the public of current and expected weather conditions. Specialists called synoptic meteorologists analyze weather observations, interpret the output of computer models, and monitor weather systems. Physical meteorologists study the physical and chemical properties of the atmosphere. Dynamic meteorologists focus on creating models of atmospheric circulation.
Contributor: Joseph M. Moran, Ph.D., Professor Emeritus, Department of Earth Science, University of Wisconsin, Green Bay; Associate Director, Education Program, American Meteorological Society.
How to cite this article:
To cite this article, World Book recommends the following format:
Moran, Joseph M. "Weather." World Book Online Reference Center. 2005. World Book, Inc. http://www.worldbookonline.com/wb/Article?id=ar596160.
Contributor: Joseph M. Moran, Ph.D., Professor Emeritus, Department of Earth Science, University of Wisconsin, Green Bay; Associate Director, Education Program, American Meteorological Society.
How to cite this article: To cite this article, World Book recommends the following format: Moran, Joseph M. "Weather." World Book Online Reference Center. 2005. World Book, Inc. http://www.worldbookonline.com/wb/Article?id=ar596160.
|› Return to Topics||› Back to Top|

சூரியனிலிருந்து வரும் வெப்ப சக்தி இந்த அடுக்கை மற்றும் இதனடியில் உள்ள பூமியின் மேற்பரப்பையும் சூடு படுத்தி பிறகு இதனுடன் தொடர்புள்ள காற்றை விரிவாக்குகின்றது. இந்த குறைந்த அடர்த்தியுடைய காற்று மேலெழுகிறது, அவ்விடத்தை அதிக அடர்த்தியுள்ள குளிர்ந்த காற்று நிரப்புகின்றது. இவ்வாறு ஏற்படும் செயல் வளிமண்டலத்தில் சுழற்சியை ஏற்படுத்துகின்றது அதனால் வெப்ப சக்தி நகர்ந்து வானிலை மற்றும் பருவநிலை ஏற்பட காரணமாகின்றது.

சூரியனிலிருந்து வரும் வெப்ப சக்தி இந்த அடுக்கை மற்றும் இதனடியில் உள்ள பூமியின் மேற்பரப்பையும் சூடு படுத்தி பிறகு இதனுடன் தொடர்புள்ள காற்றை விரிவாக்குகின்றது. இந்த குறைந்த அடர்த்தியுடைய காற்று மேலெழுகிறது, அவ்விடத்தை அதிக அடர்த்தியுள்ள குளிர்ந்த காற்று நிரப்புகின்றது. இவ்வாறு ஏற்படும் செயல் வளிமண்டலத்தில் சுழற்சியை ஏற்படுத்துகின்றது அதனால் வெப்ப சக்தி நகர்ந்து வானிலை மற்றும் பருவநிலை ஏற்பட காரணமாகின்றது.

The heat power that comes from the sun and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth.

The heat power that comes from the sun and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth and the surface of the earth.

The primary wind turtle forms 30° stages from the station and the upper stages and the upper stages forms 30° and 60° stages in the central-central district.

நிலநடுக்கோட்டிலிருந்து

நேர்ககோட்டில்

பெருங்கடல்களின்

|
||
|
Calspace Courses
Climate Change · Part One
Climate Change 1 Syllabus
1.0 - Introduction
2.0 - The Earth's Natural Greenhouse Effect
3.0 - The Greenhouse Gases
4.0 - CO2 Emissions
5.0 - The Earth's Carbon Reservoirs
6.0 - Carbon Cycling: Some Examples
7.0 - Climate and Weather
8.0 - Global Wind Systems
9.0 - Clouds, Storms and Climates
10.0 - Global Ocean Circulation
11.0 - El Niño and the Southern Oscillation
12.0 - Outlook for the Future
Climate Change · Part Two
Introduction to Astronomy
Life in the Universe
Glossary: Climate Change
Glossary: Astronomy
Glossary: Life in Universe
|
||
|
Syllabus: Climate Change 1: The Earth’s Climate System
Instructor: Prof. Wolfgang H. Berger, Teaching Assistant: Patty Anderson
Description:
Confused about the global warming Debate? This is your chance to get the story straight from scientists at Scripps Institution of Oceanography, UCSD. This introductory on-line course presents Earth’s climate system and explores the science and politics of global climate change. This 5 week course consists of 12 lessons. Course topics include the greenhouse effect, El Niño, ocean circulation, the science and politics of global warming and climate change impacts on California. All the reading, course material and assessments are on-line, there are no regularly scheduled class meetings: learn where and when you want! Included are printable lecture notes, engaging discussion groups, weekly group assignments and links to additional material.
It is an introductory course; there are no prerequisites.
Text: Our courses are self-written and all lecture notes and reading material are available on-line as html documents and printable pdf files. There is no other required text.
Method of Teaching: This is an on-line course, all course materials are available on-line. Learning methods include printable lecture notes, asynchronous threaded discussions, weekly assignments, on-line short quizzes at the end of each chapter, and links to additional material.
Grading:
- 20%: Thoughtful participation in on-line threaded discussions.
- 30%: Successful completion of short weekly assignments (i.e. writing a short essay or position piece, outside web-based research on a class topics, etc.)
- 50% Short quizzes at the end of each chapter (multiple choice and short answer)
Topical Outline: The course is 5 weeks; we introduce 2-3 lessons per week for a total of 12 lessons. Each lesson requires about 2 hours to complete – including reading, a short assignment, discussion and a quiz.
Week 1
- Lesson 1: Introduction
-Climate in the Spotlight, -The Spectrum of Scientific Opinion, -Pundits, Advocates and Apocalypse, -How to Tell Science from Rubbish
- Lesson 2: The Earth’s Natural Greenhouse Effect
-General Overview ,-Why the Earth is a Nice Place to Live,-The Radiative Balance,-The Importance of Water
Week 2
- Lesson 3: greenhouse gases
-Greenhouse Gases: An Overview, -The Role of Carbon Dioxide, -The Role of Methane, -Major Uncertainties
- Lesson 4: CO2 Emissions
-Human Emissions of CO2, -How Much Carbon in the Ground?, -Different Concerns of Rich and Poor Countries
Week 3
- Lesson 5: The Earth’s Carbon Reservoirs
-What is Biogeochemistry?, -Why is the Atmospheric Carbon Reservoir so Small?, -Breathing of Gaia, -The Missing CO2 Sink
- Lesson 6: Carbon Cycling: Some Examples
-The Physical Carbon Pump, -The Biological Carbon Pump, -The Marine Carbon Cycle, -The Terrestrial Carbon Cycle
Week 4
- Lesson 7: Climate and Weather
-Climate and Weather: Some Definitions, -The Earth’s Climate Machine
- Lesson 8: Global Wind Systems
-Trade Windsand the Hadley Cell,-The Highs and Lows of the Westerlies, -The Vital Importance of Monsoon Rains, -Why are there Seasons?
Week 5
- Lesson 9: Clouds, Storms and Climate
-Cloud Formation and Climate,-Hurricanes and Global Warming
- Lesson 10: Global Ocean Circulation
-Introduction and Overview, -Strawberries in Norway, -The Icelandic Whirlpool,-Origin of the Gulf Stream,-The Deep Atlantic Conveyor
Week 6
- Lesson 11: El Niño and the Southern Oscillation
-El Niño and its Effects,-Upwelling and Climate
- Lesson 12: Outlook for the Future
-Introduction to Climate Change,-Advances in Computer Modeling,-Physics versus Fudge Factors
Objectives
Upon completion of this course students should be able to describe how the Earth’s climate system works and summarize general atmosphere circulation patterns, ocean circulation patterns and climate oscillations such as the El-Niño Southern Oscillation. Students should be able to illustrate components of the Earth’s carbon cycle and quantitatively describe how addition of CO2 to the atmosphere through burning fossil fuels will influence the climate. Importantly, students will gain the scientific basis to analyze and critique policy issues related to global warming.
|
|

Question: what type of turtle forms 30 degrees stages from the station

The primary wind turtle forms 30° stages from the station and the upper stages and the upper stages forms 30° and 60° stages in the central-central district.

what type of turtle forms 30 degrees stages from the station

Question: where are the upper stages of wind turtle formation located

where are the upper stages of wind turtle formation located

Question: which type of turtle forms 30 degrees stages from the station and the upper stages

முதன்மை வளிமண்டல சுழற்சியின் தடத்தில் நிலநடுக்கோட்டிலிருந்து 30 ° பாகைகள் உருவாகும் வியாபாரக் காற்றுகள்

which type of turtle forms 30 degrees stages from the station and the upper stages

Question: how far does the primary wind turtle form from the station

how far does the primary wind turtle form from the station

Question: where does the wind turtle form 30° and 60° stages

where does the wind turtle form 30° and 60° stages

Question: how does the primary wind turtle form

30 ° பாகைகள் உருவாகும் வியாபாரக் காற்றுகள் மற்றும் மேற்கத்திய காற்றுகள் இவை மத்திய - நில நேர்ககோட்டில் 30 ° மற்றும் 60 ° பாகைக்குள் உருவாகின்றன . பெருங்கடல்களின்

Question: where does the primary wind turtle form

The primary wind turtle forms 30 ° stages from the station and the upper stages and the upper stages forms 30 ° and 60 ° stages in the central - central district .

முதன்மை வளிமண்டல சுழற்சியின் தடத்தில் நிலநடுக்கோட்டிலிருந்து 30° பாகைகள் உருவாகும் வியாபாரக் காற்றுகள் மற்றும் மேற்கத்திய காற்றுகள் இவை மத்திய-நில நேர்ககோட்டில் 30° மற்றும் 60° பாகைக்குள் உருவாகின்றன. பெருங்கடல்களின்

முதன்மை வளிமண்டல சுழற்சியின் தடத்தில் நிலநடுக்கோட்டிலிருந்து 30° பாகைகள் உருவாகும் வியாபாரக் காற்றுகள் மற்றும் மேற்கத்திய காற்றுகள் இவை மத்திய-நில நேர்ககோட்டில் 30° மற்றும் 60° பாகைக்குள் உருவாகின்றன. பெருங்கடல்களின்

The primary wind turtle forms 30° stages from the station and the upper stages and the upper stages forms 30° and 60° stages in the central-central district.

The primary wind turtle forms 30° stages from the station and the upper stages and the upper stages forms 30° and 60° stages in the central-central district.

The mountains and the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains.

From natural science to social science, from risks to solutions, from identifying Planetary Boundaries to managing Global Commons: The Potsdam Institute for Climate Impact Research (PIK) is advancing the frontier of integrated research for global sustainability, and for a safe and just climate future. A member of the Leibniz Association, the institute is based in Potsdam, Brandenburg and connected with the global scientific community. Drawing on excellent research, PIK provides relevant scientific advice for policy decision-making. The institute’s international staff of about 400 is led by a committed interdisciplinary team of Directors. This is science – for a safe tomorrow.
News
Numbers
11 proxy data series
Never before in over 1000 years the Gulf Stream System (also known as the Atlantic Meridional Overturning Circulation AMOC), has been as weak as in the last decades. PIK researchers have determined evidence of the AMOC weakening with the help of 11 proxy data series (information gathered by so called climate archives like ocean sediments, corals etc): They have compiled 11 independent data series from the North Atlantic, almost all of them from deep-sea sediment cores. They all provide a consistent picture about the flow characteristics of the Gulf Stream System and its weakening in the past 70 years. The slowdown is likely related to man-made climate change.
100 coronaviruses
Over the past century, global greenhouse gas emissions have led to a sharp increase in the number of bat species in the southern Chinese Yunnan province. Bats in this area have been suggested as the original carriers of SARS-CoV-2, the virus that causes Covid-19. Scientists from Cambridge, Potsdam and Hawaii showed in a study that climate change caused shifts in the natural vegetation of the region, which allowed c. 40 bat species, carrying around 100 coronaviruses, to expand into newly suitable habitat. This process would have likely created new opportunities for viruses to be transmitted or evolve, potentially facilitating the eventual spill-over to humans. In this way, climate change may have played an important role in the outbreak of SARS-CoV-2.
3 Million Years
Ocean floor deposits and model calculations have confirmed that in the past 3 million years, the global mean temperature has never been more than two degrees above pre-industrial levels, with fluctuating CO2 levels in the atmosphere. Since the beginning of industrialization, more CO2 has accumulated in the atmosphere through the burning of coal, oil and gas than probably ever before in the past 3 million years. Thus, in our current century, there is real threat that without effective climate policy the 2-degree limit of global warming will be breached for the first time – with far-reaching consequences.
+1°C = -5% growth
Day-to-day variations in temperature, i.e. short-term variability, has a substantial impact on macroeconomic growth, according to an article by Maximilian Kotz et al, published in Nature Climate Change. If this variability increases by one degree Celsius, economic growth is reduced on average by 5 percentage-points. Particularly affected are economies in low-income regions of the global South, where seasonal temperature differences can be as small as 3°C and farmers and small business owners have not yet cultivated resilience against temperature variability. This is in contrast to Economies in Canada or Russia, where average monthly temperature varies by more than 40°C within a year and economic actors seem better prepared to cope with daily temperature fluctuations than in low-latitude regions
99% industry
Almost all of industry energy needs in Europe can be satisfied with clean power by 2050. Replacing fossil fuels with low-CO2 electricity is key to stabilize our climate. 78% of industry’s energy demand is electrifiable with technologies that are already established, Potsdam researchers showed, while 99% can be achieved with the addition of technologies currently under development. However, industry electrification leads to greenhouse gas emissions reductions only if power generation gets greener. If we do this, in line with the European Green Deal’s targets, energy-related industry emissions would become minimal by mid-century, leaving only process emissions from chemical reactions and the like which account for around one fifth of current industry emissions.
10 days = -1% growth
Economic growth goes down when the number of wet days and days with extreme rainfall go up. PIK researchers found that statistically 10 more wet days in a year reduce economic growth of a region by 1%. Rich countries are most severely affected, especially the manufacturing and service sectors. The data analysis of more than 1.500 regions over the past 40 years shows a clear connection and suggests that a rising number of daily rainfall extremes, caused by human-made climate change, will harm the global economy.

ஓட்டமும் வானிலை மாற்றத்தில் பெரும் பங்கு வகிக்கின்றன, முக்கியமாக வெப்ப ஹேலைன் சுழற்சி பூமத்திய கடல்களில் இருந்து துருவக்கடல்களுக்கு வெப்ப ஆற்றலைப் பரப்புகிறது.

ஓட்டமும் வானிலை மாற்றத்தில் பெரும் பங்கு வகிக்கின்றன, முக்கியமாக வெப்ப ஹேலைன் சுழற்சி பூமத்திய கடல்களில் இருந்து துருவக்கடல்களுக்கு வெப்ப ஆற்றலைப் பரப்புகிறது.

The mountains and the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains.

The mountains and the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains of the mountains.

It often passes through the mountains or rivers of the mountains This mountains are the most important and are caused by the disturbances of the mountains of the mountains that will occur during the heat period. The mountains of the mountains varies rapidly from this place to the place, it varies from several meters to a few miles of meters. The mountains of the mountains that will be found in each place and the mountains of the mountains due to the mountains of the mountains, the mountains of the mountains and the changes of the mountains.

பெரும்பாலும்

சென்றடைகிறது

முக்கியமானது

ஏற்பட்டுக்கொண்டிருக்கும்

அமைப்புகளின்

அரிப்புகளுக்கும்

காரணமாகின்றது

வேறுபடுகின்றது

மாறுபடுகின்றது

|.|
Graphic by: Dan Bramer
Water is the source of all life on earth. The distribution of water, however, is quite varied; many locations have plenty of it while others have very little. Water exists on earth as a solid (ice), liquid or gas (water vapor). Oceans, rivers, clouds, and rain, all of which contain water, are in a frequent state of change (surface water evaporates, cloud water precipitates, rainfall infiltrates the ground, etc.). However, the total amount of the earth's water does not change. The circulation and conservation of earth's water is called the "hydrologic cycle". The Hydrologic Cycle module has been organized into the following sections:
The navigation menu (left) for this module is called "Hydrologic Cycle" and the menu items are arranged in a recommended sequence, beginning with this introduction. In addition, this entire web server is accessible in both "graphics" and "text"-based modes, a feature controlled from the blue "User Interface" menu (located beneath the black navigation menus). More information about the user interface options, the navigation system, or WW2010 in general is accessible from About This Server.

Question: the disturbances of the mountains of mountains will occur during what period

காலமாக ஏற்பட்டுக்கொண்டிருக்கும் புவியின் மேற்புற அமைப்புகளின் அரிப்புகளுக்கும் காரணமாகின்றது . மழை பொழிவது இடத்திற்கு இடம் வெகுவாக வேறுபடுகின்றது , அது பல மீட்டரில் இருந்து சில மில்லி மீட்டர் வரை மாறுபடுகின்றது . ஒவ்வொரு இடத்திலும் காணப்படும் வளிமண்டல சுழற்சி , மேற்புற அமைப்பு மற்றும் வெப்ப

It often passes through the mountains or rivers of the mountains This mountains are the most important and are caused by the disturbances of the mountains of the mountains that will occur during the heat period. The mountains of the mountains varies rapidly from this place to the place, it varies from several meters to a few miles of meters. The mountains of the mountains that will be found in each place and the mountains of the mountains due to the mountains of the mountains, the mountains of the mountains and the changes of the mountains.

the disturbances of the mountains of mountains will occur during what period

Question: how long is the range of the range from a place to a place

how long is the range of the range from a place to a place

Question: how long does it take for the mountains to change from one place to another

பல மீட்டரில் இருந்து சில

how long does it take for the mountains to change from one place to another

Question: how far does the range of the mountains from the place to the place vary

பல மீட்டரில்

how far does the range of the mountains from the place to the place vary

Question: what is the most important

Question: what is a river that passes through the mountains

what is a river that passes through the mountains

Question: when will the disturbances of the mountains of mountains occur

வெகு காலமாக ஏற்பட்டுக்கொண்டிருக்கும் புவியின் மேற்புற அமைப்புகளின் அரிப்புகளுக்கும் காரணமாகின்றது . மழை பொழிவது இடத்திற்கு இடம் வெகுவாக வேறுபடுகின்றது , அது பல மீட்டரில் இருந்து சில மில்லி மீட்டர் வரை மாறுபடுகின்றது . ஒவ்வொரு இடத்திலும் காணப்படும் வளிமண்டல சுழற்சி , மேற்புற அமைப்பு மற்றும் வெப்ப

when will the disturbances of the mountains of mountains occur

Question: the disturbances of the mountains of mountains will occur during what

வெகு காலமாக ஏற்பட்டுக்கொண்டிருக்கும் புவியின் மேற்புற அமைப்புகளின் அரிப்புகளுக்கும் காரணமாகின்றது . மழை பொழிவது இடத்திற்கு இடம் வெகுவாக வேறுபடுகின்றது , அது பல மீட்டரில் இருந்து சில மில்லி மீட்டர் வரை மாறுபடுகின்றது . ஒவ்வொரு இடத்திலும் காணப்படும் வளிமண்டல சுழற்சி , மேற்புற அமைப்பு மற்றும் வெப்ப

the disturbances of the mountains of mountains will occur during what

It often passes through the mountains or rivers of the mountains This mountains are the most important and are caused by the disturbances of the mountains of the mountains that will occur during the heat period . The mountains of the mountains varies rapidly from this place to the place , it varies from several meters to a few miles of meters . The mountains of the mountains that will be found in each place and the mountains of the mountains due to the mountains of the mountains , the mountains of the mountains and the changes of the mountains .

இது பெரும்பாலும் ஆற்றின் மூலமாக பெருங்கடல் அல்லது ஏரிகளை சென்றடைகிறது இந்நீரின் சுழற்சி பூமியில் உயிரினங்கள் வாழ மிக முக்கியமானது மற்றும் வெகு காலமாக ஏற்பட்டுக்கொண்டிருக்கும் புவியின் மேற்புற அமைப்புகளின் அரிப்புகளுக்கும் காரணமாகின்றது. மழை பொழிவது இடத்திற்கு இடம் வெகுவாக வேறுபடுகின்றது, அது பல மீட்டரில் இருந்து சில மில்லி மீட்டர் வரை மாறுபடுகின்றது. ஒவ்வொரு இடத்திலும் காணப்படும் வளிமண்டல சுழற்சி, மேற்புற அமைப்பு மற்றும் வெப்ப மாற்றத்தை பொறுத்தே அவ்விடத்து மழை அமையும்.

இது பெரும்பாலும் ஆற்றின் மூலமாக பெருங்கடல் அல்லது ஏரிகளை சென்றடைகிறது இந்நீரின் சுழற்சி பூமியில் உயிரினங்கள் வாழ மிக முக்கியமானது மற்றும் வெகு காலமாக ஏற்பட்டுக்கொண்டிருக்கும் புவியின் மேற்புற அமைப்புகளின் அரிப்புகளுக்கும் காரணமாகின்றது. மழை பொழிவது இடத்திற்கு இடம் வெகுவாக வேறுபடுகின்றது, அது பல மீட்டரில் இருந்து சில மில்லி மீட்டர் வரை மாறுபடுகின்றது. ஒவ்வொரு இடத்திலும் காணப்படும் வளிமண்டல சுழற்சி, மேற்புற அமைப்பு மற்றும் வெப்ப மாற்றத்தை பொறுத்தே அவ்விடத்து மழை அமையும்.

It often passes through the mountains or rivers of the mountains This mountains are the most important and are caused by the disturbances of the mountains of the mountains that will occur during the heat period. The mountains of the mountains varies rapidly from this place to the place, it varies from several meters to a few miles of meters. The mountains of the mountains that will be found in each place and the mountains of the mountains due to the mountains of the mountains, the mountains of the mountains and the changes of the mountains.

It often passes through the mountains or rivers of the mountains This mountains are the most important and are caused by the disturbances of the mountains of the mountains that will occur during the heat period. The mountains of the mountains varies rapidly from this place to the place, it varies from several meters to a few miles of meters. The mountains of the mountains that will be found in each place and the mountains of the mountains due to the mountains of the mountains, the mountains of the mountains and the changes of the mountains.

And the earth will be shattered by the shadows of the shadows of the shadows of the shadows.

Through the earth and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth.

பூமியின் பகுதிகளை அதன் நில நேர்க்கோட்டின் படி சராசரியான ஒரே தட்பவெப்ப நிலைகள் உள்ளவைகளாக பிரிக்கலாம். பூமத்திய ரேகையிலிருந்து துருவங்கள் வரையிலான தட்பவெப்பத்தை வெப்ப வளையம் (அல்லது ஈக்வடோரியல்), மிதவெப்ப வளையம், மிதமான வளையம் மற்றும் துருவ வளைய

பூமியின் பகுதிகளை அதன் நில நேர்க்கோட்டின் படி சராசரியான ஒரே தட்பவெப்ப நிலைகள் உள்ளவைகளாக பிரிக்கலாம்.

பூமத்திய ரேகையிலிருந்து துருவங்கள் வரையிலான தட்பவெப்பத்தை வெப்ப வளையம் (அல்லது ஈக்வடோரியல்), மிதவெப்ப வளையம், மிதமான வளையம் மற்றும் துருவ வளைய

And the earth will be shattered by the shadows of the shadows of the shadows of the shadows. Through the earth and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth.

And the earth will be shattered by the shadows of the shadows of the shadows of the shadows.

Through the earth and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth.

In the atmosphere, the magnitude of the basic atmosphere is divided into the path to the Strado (stratosphere), the Mesosphere (mesosphere), and the atmosphere.

Every one of them will be able to do so, and every one will be able to do so, and every one will be able to do so, and every one will be able to do so, and every one will be able to do so, and every one will be able to do so.

நாசா படம். வளிமண்டலத்தில், அடி வளிமண்டலத்தின் மேற்பகுதி, வழக்கமாக ஸ்ட்ரடோ அடுக்கு (stratosphere), மீசோ அடுக்கு (mesosphere), வெப்பஅடுக்கு என பிரிக்கப்படுகிறது. ஒவ்வொரு அடுக்கும், அதன் உயரத்திற்கு ஏற்ப, தோன்றும் வெப்ப மாறுபாட்டிற்கு ஏற்றாற்போல் வெவ்வேறு இழப்பு விகிதத்தைக் கொண்டிருக்கும்.

நாசா படம். வளிமண்டலத்தில், அடி வளிமண்டலத்தின் மேற்பகுதி, வழக்கமாக ஸ்ட்ரடோ அடுக்கு (stratosphere), மீசோ அடுக்கு (mesosphere), வெப்பஅடுக்கு என பிரிக்கப்படுகிறது.

ஒவ்வொரு அடுக்கும், அதன் உயரத்திற்கு ஏற்ப, தோன்றும் வெப்ப மாறுபாட்டிற்கு ஏற்றாற்போல் வெவ்வேறு இழப்பு விகிதத்தைக் கொண்டிருக்கும்.

In the atmosphere, the magnitude of the basic atmosphere is divided into the path to the Strado (stratosphere), the Mesosphere (mesosphere), and the atmosphere. Every one of them will be able to do so, and every one will be able to do so, and every one will be able to do so, and every one will be able to do so, and every one will be able to do so, and every one will be able to do so.

In the atmosphere, the magnitude of the basic atmosphere is divided into the path to the Strado (stratosphere), the Mesosphere (mesosphere), and the atmosphere.

Every one of them will be able to do so, and every one will be able to do so, and every one will be able to do so, and every one will be able to do so, and every one will be able to do so, and every one will be able to do so.

A part necessary for the living of living in the earth is the river in the river, which protects the flooding of the earth from the river from the river from the river from the river from the river.

ஊடாடுகிறது. பூமியில் உயிர்கள் வாழ்வதற்கு தேவையான ஒரு பகுதி வளிமண்டலத்தில் உள்ள ஓசோன் அடுக்கு ஆகும், இது ஸ்ட்ரடோ அடுக்கில் இருந்துகொண்டு பூமியின் மேற்பரப்பை புற ஊதா கதிர்களிடமிருந்து பாதுகாக்கிறது.

ஊடாடுகிறது. பூமியில் உயிர்கள் வாழ்வதற்கு தேவையான ஒரு பகுதி வளிமண்டலத்தில் உள்ள ஓசோன் அடுக்கு ஆகும், இது ஸ்ட்ரடோ அடுக்கில் இருந்துகொண்டு பூமியின் மேற்பரப்பை புற ஊதா கதிர்களிடமிருந்து பாதுகாக்கிறது.

A part necessary for the living of living in the earth is the river in the river, which protects the flooding of the earth from the river from the river from the river from the river from the river.

A part necessary for the living of living in the earth is the river in the river, which protects the flooding of the earth from the river from the river from the river from the river from the river.

When the heat flows, the speed of some flows in the outer air of the aircraft increases and a rise is released by the power of the pressure of the aircraft. As a result, the same rise is<unk> constantly entering the aircraft. Because, as the constant hydrogen flows is quite low, it takes the speed of the release very quickly.

வளிமண்டலத்தின்

மூலக்கூறுகளின்

சக்தியிலிருந்த

விடுபடுகின்றது

விண்வெளியில்

The Aeronomy of Hydrogen in the Atmosphere of the Earth.
Abstract
The distribution of hydrogen compounds between 50 km and the exobase is calculated subject to the condition that the upward flux of hydrogen atoms be sufficient to supply the thermal escape flux. The effect of varying many parameters, such as exospheric temperature, chemical rate constants, solar UV flux, and atmospheric transport coefficients is explored. It is found that H2 plays an important role in the chemistry and transport even above 100 km. It is found that the escape flux is determined mainly by the total mixing ratio and relatively insensitive to other factors at exospheric temperatures above 1000K, but is limited by the exosbase flow at lower temperatures. A thermal escape flux of 7×107 cm2 sec1 above 1000K is difficult to reconcile with a combine mixing ratio of H2O, H2 and CH4 greater than about 2 ppm at 50 km.
- Publication:
- Journal of Atmospheric Sciences
- Pub Date:
- May 1974
- DOI:
- 10.1175/1520-0469(1974)031<1118:TAOHIT>2.0.CO;2
- Bibcode:
- 1974JAtS...31.1118L

Question: what is constantly entering the aircraft

When the heat flows, the speed of some flows in the outer air of the aircraft increases and a rise is released by the power of the pressure of the aircraft. As a result, the same rise is<unk> constantly entering the aircraft. Because, as the constant hydrogen flows is quite low, it takes the speed of the release very quickly.

what is constantly entering the aircraft

Question: what causes the speed of some flows in the outer air of the aircraft to increase

"வெப்ப ஆற்றலால்

what causes the speed of some flows in the outer air of the aircraft to increase

Question: what happens to the speed of some flows in the outer air of an aircraft

what happens to the speed of some flows in the outer air of an aircraft

Question: what is the result of the same rise constantly entering the aircraft

what is the result of the same rise constantly entering the aircraft

Question: what is released by the power of the pressure of the aircraft

ஒரு சமயம் அவை புவியின் ஈர்ப்பு சக்தியிலிருந்த விடுபடுகின்றது . இதன் விளைவாக நிதானமாக அதே சமயம் நிலையாக வளிமண்டலம் விண்வெளியில் நுழைகிறது . ஏனெனில் , நிலையற்ற ஹைட்ரஜன் மூலக்கூறு நிறை குறைவாக இருப்பதால் , அது மிக விரைவிலேயே விடுபடும் வேகத்தை அடைகிறது .

what is released by the power of the pressure of the aircraft

Question: when does the speed of some flows in the outer air of the aircraft increase

"வெப்ப ஆற்றலால்

when does the speed of some flows in the outer air of the aircraft increase

Question: what releases a rise in the speed of some flows

புவியின் ஈர்ப்பு சக்தியிலிருந்த

what releases a rise in the speed of some flows

When the heat flows , the speed of some flows in the outer air of the aircraft increases and a rise is released by the power of the pressure of the aircraft . As a result , the same rise is < unk > constantly entering the aircraft . Because , as the constant hydrogen flows is quite low , it takes the speed of the release very quickly .

வெப்ப ஆற்றலால், வளிமண்டலத்தின் வெளி விளிம்பில் உள்ள சில மூலக்கூறுகளின் வேகம் அதிகரித்து ஒரு சமயம் அவை புவியின் ஈர்ப்பு சக்தியிலிருந்த விடுபடுகின்றது. இதன் விளைவாக நிதானமாக அதே சமயம் நிலையாக வளிமண்டலம் விண்வெளியில் நுழைகிறது. ஏனெனில், நிலையற்ற ஹைட்ரஜன் மூலக்கூறு நிறை குறைவாக இருப்பதால், அது மிக விரைவிலேயே விடுபடும் வேகத்தை அடைகிறது.

வெப்ப ஆற்றலால், வளிமண்டலத்தின் வெளி விளிம்பில் உள்ள சில மூலக்கூறுகளின் வேகம் அதிகரித்து ஒரு சமயம் அவை புவியின் ஈர்ப்பு சக்தியிலிருந்த விடுபடுகின்றது. இதன் விளைவாக நிதானமாக அதே சமயம் நிலையாக வளிமண்டலம் விண்வெளியில் நுழைகிறது. ஏனெனில், நிலையற்ற ஹைட்ரஜன் மூலக்கூறு நிறை குறைவாக இருப்பதால், அது மிக விரைவிலேயே விடுபடும் வேகத்தை அடைகிறது.

When the heat flows, the speed of some flows in the outer air of the aircraft increases and a rise is released by the power of the pressure of the aircraft. As a result, the same rise is<unk> constantly entering the aircraft. Because, as the constant hydrogen flows is quite low, it takes the speed of the release very quickly.

When the heat flows, the speed of some flows in the outer air of the aircraft increases and a rise is released by the power of the pressure of the aircraft. As a result, the same rise is<unk> constantly entering the aircraft. Because, as the constant hydrogen flows is quite low, it takes the speed of the release very quickly.

It is also the way that the wind is more rapidly entering than the other waters; this is due to the fact that the earth is from the starting point to the current state of flooding.

The lighting is a great way to get it.

விண்வெளிக்குள்

நிலையிலிருந்து

ஒளிச்சேர்க்கை

Question: what is a great way to get flooding

It is also the way that the wind is more rapidly entering than the other waters; this is due to the fact that the earth is from the starting point to the current state of flooding.

The lighting is a great way to get it.

Question: what is the current state of the earth

The lighting is a great way to get it.

Question: what is more rapidly entering than the other waters

The lighting is a great way to get it.

what is more rapidly entering than the other waters

Question: where does the current state of flooding come from

The lighting is a great way to get it.

where does the current state of flooding come from

Question: how does the wind affect the other waters

மிக வேகமாக விண்வெளிக்குள் நுழைகிறது

The lighting is a great way to get it.

how does the wind affect the other waters

Question: why is the earth more flooded than other waters

மிக வேகமாக விண்வெளிக்குள் நுழைகிறது

The lighting is a great way to get it.

why is the earth more flooded than other waters

It is also the way that the wind is more rapidly entering than the other waters ; this is due to the fact that the earth is from the starting point to the current state of flooding .

மேலும் மற்ற வாயுக்களை விட மிக வேகமாக விண்வெளிக்குள் நுழைகிறது. இதுவே பூமி ஆரம்ப ஒடுக்க நிலையிலிருந்து தற்போதைய ஆக்சிஜனேற்ற நிலையை அடைவதற்கு காரணமாகும். ஒளிச்சேர்க்கை ஆக்சிஜன் மிகுதியாக கிடைக்க வழி செய்கிறது.

மேலும் மற்ற வாயுக்களை விட மிக வேகமாக விண்வெளிக்குள் நுழைகிறது. இதுவே பூமி ஆரம்ப ஒடுக்க நிலையிலிருந்து தற்போதைய ஆக்சிஜனேற்ற நிலையை அடைவதற்கு காரணமாகும்.

ஒளிச்சேர்க்கை ஆக்சிஜன் மிகுதியாக கிடைக்க வழி செய்கிறது.

It is also the way that the wind is more rapidly entering than the other waters; this is due to the fact that the earth is from the starting point to the current state of flooding. The lighting is a great way to get it.

It is also the way that the wind is more rapidly entering than the other waters; this is due to the fact that the earth is from the starting point to the current state of flooding.

It is believed that this will be the reason for the sunshine to be widespread.

Thus, the nature of the hydrogen that can be removed from the sunshine of the earth, the way of life in the earth is set forth.

வளிமண்டலத்தில்

இருந்திருக்கும்

நம்பப்படுகிறது

வளிமண்டலத்திலிருந்து

வெளியேறக்கூடிய

வாழ்க்கையின்

முன்னேற்றத்திற்கு

வகுத்திருக்கிறது

Question: what element can be removed from the earth's sunshine

It is believed that this will be the reason for the sunshine to be widespread.

Thus, the nature of the hydrogen that can be removed from the sunshine of the earth, the way of life in the earth is set forth.

what element can be removed from the earth's sunshine

Question: what is believed to be the reason for the widespread use of hydrogen

what is believed to be the reason for the widespread use of hydrogen

Question: what is set forth when hydrogen is removed from the earth

வாழ்க்கையின் முன்னேற்றத்திற்கு

what is set forth when hydrogen is removed from the earth

Question: what can be removed from the sunshine of the earth

ஹைட்ரஜனின் தன்மை

what can be removed from the sunshine of the earth

Question: what is set forth when hydrogen is removed from the sun

பூமியில் வாழ்க்கையின் முன்னேற்றத்திற்கு

what is set forth when hydrogen is removed from the sun

Question: what is believed to be the reason for the earths sunshine to be

what is believed to be the reason for the earths sunshine to be

Question: the nature of the hydrogen that can be removed from the earth causes what to be widespread

the nature of the hydrogen that can be removed from the earth causes what to be widespread

It is believed that this will be the reason for the sunshine to be widespread .

Thus , the nature of the hydrogen that can be removed from the sunshine of the earth , the way of life in the earth is set forth .

வளிமண்டலத்தில் ஆக்சிஜன் அதிகமாக பரவுவதற்கு இதுவே காரணமாக இருந்திருக்கும் என நம்பப்படுகிறது. எனவே, பூமியின் வளிமண்டலத்திலிருந்து வெளியேறக்கூடிய ஹைட்ரஜனின் தன்மை, பூமியில் வாழ்க்கையின் முன்னேற்றத்திற்கு வழி வகுத்திருக்கிறது.

வளிமண்டலத்தில் ஆக்சிஜன் அதிகமாக பரவுவதற்கு இதுவே காரணமாக இருந்திருக்கும் என நம்பப்படுகிறது.

எனவே, பூமியின் வளிமண்டலத்திலிருந்து வெளியேறக்கூடிய ஹைட்ரஜனின் தன்மை, பூமியில் வாழ்க்கையின் முன்னேற்றத்திற்கு வழி வகுத்திருக்கிறது.

It is believed that this will be the reason for the sunshine to be widespread. Thus, the nature of the hydrogen that can be removed from the sunshine of the earth, the way of life in the earth is set forth.

It is believed that this will be the reason for the sunshine to be widespread.

Thus, the nature of the hydrogen that can be removed from the sunshine of the earth, the way of life in the earth is set forth.

At the current oxygen-filled lighthouse, hydrogen is shifted before it leaves the lighthouse.

வளிமண்டலத்திலிருந்து

வெளியேறக்கூடிய

வாழ்க்கையின்

முன்னேற்றத்திற்கு

வகுத்திருக்கிறது

வளிமண்டலத்தில்

வளிமண்டலத்தை

மாற்றப்படுகிறது

Hydrogen Loss from the Terrestrial Planets
Abstract
Theoretical and experimental research on the escape of light gases from planetary atmospheres is reviewed. Global-average data are utilized throughout the review, and both thermal escape (Jeans escape) processes and nonthermal escape processes are considered. Basic escape mechanisms and associated processes of loss and of production of hydrogen atoms and molecules, ionization of hydrogen atoms, charge exchange, flux swept by the solar wind, mass accretion, molecular diffusion and eddy diffusion (mixing), and sources of hydrogen are discussed first, and research on the individual planets (Earth, Venus, Mars) follows.
- Publication:
- Annual Review of Earth and Planetary Sciences
- Pub Date:
- 1976
- DOI:
- 10.1146/annurev.ea.04.050176.001405
- Bibcode:
- 1976AREPS...4..265H
- Keywords:
- Atmospheric Physics;
- Earth Atmosphere;
- Hydrogen;
- Jeans Theory;
- Mars Atmosphere;
- Venus Atmosphere;
- Charge Exchange;
- Hydrogen Atoms;
- Hydrogen Ions;
- Molecular Gases;
- Solar Wind;
- Turbulent Diffusion;
- Lunar and Planetary Exploration

Question: hydrogen is shifted before it leaves what

நிறைந்த வளிமண்டலத்தில்

At the current oxygen-filled lighthouse, hydrogen is shifted before it leaves the lighthouse.

hydrogen is shifted before it leaves what

Question: what kind of lighthouse is the hydrogen at

what kind of lighthouse is the hydrogen at

Question: the nature of hydrogen can be removed from what

the nature of hydrogen can be removed from what

Question: what type of light is present at the lighthouse

what type of light is present at the lighthouse

Question: when is hydrogen shifted at the current oxygen filled lighthouse

வளிமண்டலத்தை விட்டு வெளியேறும் முன்னரே

when is hydrogen shifted at the current oxygen filled lighthouse

Question: what is set forth when hydrogen is removed from the sunshine

பூமியில் வாழ்க்கையின் முன்னேற்றத்திற்கு

what is set forth when hydrogen is removed from the sunshine

At the current oxygen - filled lighthouse , hydrogen is shifted before it leaves the lighthouse .

எனவே, பூமியின் வளிமண்டலத்திலிருந்து வெளியேறக்கூடிய ஹைட்ரஜனின் தன்மை, பூமியில் வாழ்க்கையின் முன்னேற்றத்திற்கு வழி வகுத்திருக்கிறது. தற்போதைய ஆக்சிஜன் நிறைந்த வளிமண்டலத்தில், ஹைட்ரஜன் வளிமண்டலத்தை விட்டு வெளியேறும் முன்னரே, நீராக மாற்றப்படுகிறது.

தற்போதைய ஆக்சிஜன் நிறைந்த வளிமண்டலத்தில், ஹைட்ரஜன் வளிமண்டலத்தை விட்டு வெளியேறும் முன்னரே, நீராக மாற்றப்படுகிறது.

Thus, the nature of the hydrogen that can be removed from the sunshine of the earth, the way of life in the earth is set forth. At the current oxygen-filled lighthouse, hydrogen is shifted before it leaves the lighthouse.

At the current oxygen-filled lighthouse, hydrogen is shifted before it leaves the lighthouse.

It is believed to be calm. According to the natural principles, it is sustainable, in the outer state of the earth's creation, the heat of the air and the materials of

It is created in the place that creates the ocean and produces the energy. This creates the ocean of the earth. In the outside, the warm ocean will be in a shrinking state.

Moreover, it’s going to be so now. This predictive change will be transformed into a crowded atmosphere several times every million years. Finally, this change occurred 700,000 years ago.

"அமைந்திருப்பதாக

கருதப்படுகிறது

கொள்கையின்படி

காந்தப்புலமானது

வெளிக்கருவில்

உருவாக்கப்படுகிறது

காந்தப்புலத்தை

உருவாக்குகிறது

வெளிக்கருவில்

மாறிக்கொண்டேயிருக்கும்

வருடத்திற்கு

மாறிக்கொண்டேயிருக்கும்

வருடங்களுக்கு

Next: MHD Dynamo Theory
Up: Magnetohydrodynamic Fluids
Previous: Interplanetary Magnetic Field
Since the Sun is the best observed of any star, it is interesting to
ask what impact the solar wind has as far as solar, and stellar, evolution
are concerned. The most obvious question is whether the mass loss due
to the wind is significant, or not. Using typical measured values (i.e.,
a typical solar wind velocity and particle density at 1 AU of
and
, respectively),
the Sun is apparently losing mass at a rate of
per year, implying a time-scale for significant mass loss of
years, or some times longer than the estimated year
age of the Sun. Clearly, the mass carried off by the solar wind has a negligible
effect on the Sun's evolution. Note, however, that many other stars in the Galaxy
exhibit significant mass loss via stellar winds. This is particularly
the case for late-type stars.
Let us now consider the angular momentum carried off by the solar wind.
Angular momentum loss is a crucially important topic in astrophysics, since
only by losing angular momentum can large, diffuse objects, such as
interstellar gas clouds, collapse under the influence of gravity to produce
small, compact objects, such as stars and proto-stars. Magnetic fields
generally play a crucial role in angular momentum loss. This is certainly
the case for the solar wind, where the solar magnetic field enforces
co-rotation with the Sun out to the Alfvén radius, . Thus, the
angular momentum carried away by a particle of mass is
, rather than
. The angular momentum
loss time-scale is, therefore, shorter than the mass loss time-scale by a factor
, making the angular momentum loss time-scale
comparable to the solar lifetime. It is clear that magnetized stellar
winds represent a very important vehicle for angular momentum loss in the
Universe. Let us investigate angular momentum loss via
stellar winds in more detail.
Under the assumption of spherical symmetry and steady flow, the azimuthal
momentum evolution equation for the solar wind, taking into account the
influence of the interplanetary magnetic field, is written
The constancy of the mass flux [see Eq. (744)] and the dependence
of [see Eq. (763)] permit the immediate integration of the
above equation to give
|
||
(770)|
where is the angular momentum per unit mass carried off by the solar wind.
In the presence of an azimuthal wind velocity, the magnetic field and
velocity components are related by an expression similar to Eq. (761):
|
||
(771)|
The fundamental physics assumption underlying the above expression is
the absence of an electric field in the frame of reference co-rotating
with the Sun. Using Eq. (772) to eliminate from Eq. (771), we obtain
(in the ecliptic plane, where )
|
||
(772)|
where
|
||
(773)|
is the radial Alfvén Mach number. The radial Alfvén Mach number
is small near the base of the corona, and about 10 at 1 AU: it passes through
unity at the Alfvén radius, , which is about AU from the Sun.
The zero denominator on the right-hand side
of Eq. (773) at implies that is
finite and continuous only if the numerator is also zero at the Alfvén radius.
This condition then determines the angular momentum content of the outflow
via
|
||
(774)|
Note that the angular momentum carried off by the solar wind is indeed
equivalent to that which would be carried off were coronal plasma to
co-rotate with the Sun out to the Alfvén radius, and subsequently outflow
at constant angular velocity. Of course, the solar wind does not actually
rotate rigidly with the Sun in the region : much of the angular
momentum in this region is carried in the form of electromagnetic stresses.
|
||
(775)|
It is easily demonstrated that the quantity
is a constant,
and can, therefore, be evaluated at to give
where
. Equations (773), (775), and (776) can
be combined to give
|
||
(776)|
In the limit
, we have , so the above
expression yields
|
||
(777)|
at large distances from the Sun. Recall, from Sect. 5.7, that if the coronal
plasma were to simply co-rotate with the Sun out to , and experience
no torque beyond this radius, then we would expect
|
||
(778)|
at large distances from the Sun.
The difference between the above two expressions is the factor ,
which is a correction for the angular momentum retained by the magnetic
field at large .
|
||
(779)|
The analysis presented above was first incorporated into a quantitative
coronal expansion model by Weber and Davis. The model of Weber and Davis is
very complicated. For instance, the solar wind is required to flow smoothly
through no less than three critical points. These are associated
with the sound speed (as in Parker's original model), the radial Alfvén
speed,
, (as described above), and the total
Alfvén speed,
.
Nevertheless, the simplified analysis
outlined above captures most of the essential features of the outflow.
For instance, Fig. 20 shows a comparison between the large- asymptotic
form for the azimuthal flow velocity predicted above [see Eq. (778)] and
that calculated by Weber and Davis, showing the close agreement between
the two.
Figure 20:
Comparison of asymptotic form for azimuthal flow velocity
of solar wind with Weber-Davis solution.
Next: MHD Dynamo Theory
Up: Magnetohydrodynamic Fluids
Previous: Interplanetary Magnetic Field
Richard Fitzpatrick
2011-03-31

Question: what is the state of the earth believed to be

It is believed to be calm. According to the natural principles, it is sustainable, in the outer state of the earth's creation, the heat of the air and the materials of

It is created in the place that creates the ocean and produces the energy. This creates the ocean of the earth. In the outside, the warm ocean will be in a shrinking state.

Moreover, it’s going to be so now. This predictive change will be transformed into a crowded atmosphere several times every million years. Finally, this change occurred 700,000 years ago.

what is the state of the earth believed to be

Question: when did the earth's climate change occur

700,000 வருடங்களுக்கு முன்

when did the earth's climate change occur

Question: how long ago did this change occur

700,000 வருடங்களுக்கு

Question: according to the natural principles, what is the state of the earth

according to the natural principles, what is the state of the earth

Question: what does the heat of the air and the materials of it create

what does the heat of the air and the materials of it create

Question: what kind of atmosphere will the warm ocean be transformed into every million years

what kind of atmosphere will the warm ocean be transformed into every million years

Question: what state will the warm ocean be in on the outside

what state will the warm ocean be in on the outside

It is believed to be calm . According to the natural principles , it is sustainable , in the outer state of the earth 's creation , the heat of the air and the materials of

It is created in the place that creates the ocean and produces the energy . This creates the ocean of the earth . In the outside , the warm ocean will be in a shrinking state .

Moreover , it ’s going to be so now . This predictive change will be transformed into a crowded atmosphere several times every million years . Finally , this change occurred 700,000 years ago .

அமைந்திருப்பதாக தோராயமாக கருதப்படுகிறது. இயக்கவியல் கொள்கையின்படி, காந்தப்புலமானது, பூமியின் உருகிய நிலையில் உள்ள வெளிக்கருவில், வெப்பம் கடத்தும் பொருள்களின் கடத்துத் திறனை உருவாக்கி மின்சாரத்தை உற்பத்தி செய்யும் இடத்தில், உருவாக்கப்படுகிறது. இதுவே, பூமியின் காந்தப்புலத்தை உருவாக்குகிறது. வெளிக்கருவில், வெப்ப கடத்துத் திறன் ஒழுங்கற்ற நிலையில் இருக்கும். மேலும், அது அவ்வப்போது மாறிக்கொண்டேயிருக்கும். இந்த காந்தப்புல மாற்றம் ஒவ்வொரு மில்லியன் வருடத்திற்கு சில முறை ஒழுங்கற்ற இடைவெளியில் மாறிக்கொண்டேயிருக்கும். இறுதியாக இந்த மாற்றம் 700,000 வருடங்களுக்கு முன் நிகழ்ந்தது.

அமைந்திருப்பதாக தோராயமாக கருதப்படுகிறது. இயக்கவியல் கொள்கையின்படி, காந்தப்புலமானது, பூமியின் உருகிய நிலையில் உள்ள வெளிக்கருவில், வெப்பம் கடத்தும் பொருள்களின்

கடத்துத் திறனை உருவாக்கி மின்சாரத்தை உற்பத்தி செய்யும் இடத்தில், உருவாக்கப்படுகிறது. இதுவே, பூமியின் காந்தப்புலத்தை உருவாக்குகிறது. வெளிக்கருவில், வெப்ப கடத்துத் திறன் ஒழுங்கற்ற நிலையில் இருக்கும்.

மேலும், அது அவ்வப்போது மாறிக்கொண்டேயிருக்கும். இந்த காந்தப்புல மாற்றம் ஒவ்வொரு மில்லியன் வருடத்திற்கு சில முறை ஒழுங்கற்ற இடைவெளியில் மாறிக்கொண்டேயிருக்கும். இறுதியாக இந்த மாற்றம் 700,000 வருடங்களுக்கு முன் நிகழ்ந்தது.

It is believed to be calm. According to the natural principles, it is sustainable, in the outer state of the earth's creation, the heat of the air and the materials of It is created in the place that creates the ocean and produces the energy. This creates the ocean of the earth. In the outside, the warm ocean will be in a shrinking state. Moreover, it’s going to be so now. This predictive change will be transformed into a crowded atmosphere several times every million years. Finally, this change occurred 700,000 years ago.

It is believed to be calm. According to the natural principles, it is sustainable, in the outer state of the earth's creation, the heat of the air and the materials of

It is created in the place that creates the ocean and produces the energy. This creates the ocean of the earth. In the outside, the warm ocean will be in a shrinking state.

Moreover, it’s going to be so now. This predictive change will be transformed into a crowded atmosphere several times every million years. Finally, this change occurred 700,000 years ago.

Thirty-three days later, we will be able to reach the end of the day.

When the sun is shining, the sun is shining, the sun is shining, the sun is shining, the sun is shining.

"காந்தப்புலதிற்கும்

காற்றுக்கும்

Question: how long does it take to reach the end of the day

Thirty-three days later, we will be able to reach the end of the day.

When the sun is shining, the sun is shining, the sun is shining, the sun is shining, the sun is shining.

how long does it take to reach the end of the day

Question: when do we see the end of the day

சூரிய காற்றுக்கும் நிகழும் மோதலினால் வான் ஆலன் கதிர்வீச்சு வளையம் உண்டாகிறது

Question: when the sun is shining, what does it mean

when the sun is shining, what does it mean

Question: how many days later will we be able to reach the end of the day

how many days later will we be able to reach the end of the day

Question: what happens when the sun is shining

Thirty - three days later , we will be able to reach the end of the day .

When the sun is shining , the sun is shining , the sun is shining , the sun is shining , the sun is shining .

நுனி புவியின் ஆரத்தை போன்று 13 மடங்கைக் கொண்டது. காந்தப்புலதிற்கும் சூரிய காற்றுக்கும் நிகழும் மோதலினால் வான் ஆலன் கதிர்வீச்சு வளையம் உண்டாகிறது.

நுனி புவியின் ஆரத்தை போன்று 13 மடங்கைக் கொண்டது.

காந்தப்புலதிற்கும் சூரிய காற்றுக்கும் நிகழும் மோதலினால் வான் ஆலன் கதிர்வீச்சு வளையம் உண்டாகிறது.

Thirty-three days later, we will be able to reach the end of the day. When the sun is shining, the sun is shining, the sun is shining, the sun is shining, the sun is shining.

Thirty-three days later, we will be able to reach the end of the day.

When the sun is shining, the sun is shining, the sun is shining, the sun is shining, the sun is shining.

And the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth.

The time of Earth's flourishment is the time of the Sun's flourishment-this time of the Sun's flourishment-this time of the Sun's flourishment is 86,400 seconds. This is a better addition than the time of the Earth's flourishment (SI). Because when the 19th century is flourishment, the current Earth's sun's flourishment is less long than the time of the Earth's flourishment.

பூமியின் கோளப்பாதை மற்றும் சுழற்சி சுழற்சி புவியின் சாய்ந்த அச்சுக்கும் (அல்லது சாய்நிலை) அதன் சுழலும் அச்சு மற்றும் கோளப்பாதைக்கும் இடையே உள்ள தொடர்பு. பூமியின் சுழலும் காலம் சூரியனை ஒப்பிடுகையில்-அதன் சராசரி சூரிய நாள்-அதாவது சராசரி சூரிய நேரத்தில் 86,400 விநாடிகளாகும். இந்த ஒவ்வொரு வினாடியும் எஸ்.ஐ (SI) முறை வினாடியை விட சிறிது கூடுதல். ஏனெனில் 19 ஆம் நூற்றாண்டை ஒப்பிடும் போது தற்போதைய பூமியின் சூரிய நாள் அலை முடுக்கத்தால் சிறிதே நீண்டிருக்கிறது.

பூமியின் கோளப்பாதை மற்றும் சுழற்சி சுழற்சி புவியின் சாய்ந்த அச்சுக்கும் (அல்லது சாய்நிலை) அதன் சுழலும் அச்சு மற்றும் கோளப்பாதைக்கும் இடையே உள்ள தொடர்பு.

பூமியின் சுழலும் காலம் சூரியனை ஒப்பிடுகையில்-அதன் சராசரி சூரிய நாள்-அதாவது சராசரி சூரிய நேரத்தில் 86,400 விநாடிகளாகும். இந்த ஒவ்வொரு வினாடியும் எஸ்.ஐ (SI) முறை வினாடியை விட சிறிது கூடுதல். ஏனெனில் 19 ஆம் நூற்றாண்டை ஒப்பிடும் போது தற்போதைய பூமியின் சூரிய நாள் அலை முடுக்கத்தால் சிறிதே நீண்டிருக்கிறது.

And the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth. The time of Earth's flourishment is the time of the Sun's flourishment-this time of the Sun's flourishment-this time of the Sun's flourishment is 86,400 seconds. This is a better addition than the time of the Earth's flourishment (SI). Because when the 19th century is flourishment, the current Earth's sun's flourishment is less long than the time of the Earth's flourishment.

And the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth, and the earth.

The time of Earth's flourishment is the time of the Sun's flourishment-this time of the Sun's flourishment-this time of the Sun's flourishment is 86,400 seconds. This is a better addition than the time of the Earth's flourishment (SI). Because when the 19th century is flourishment, the current Earth's sun's flourishment is less long than the time of the Earth's flourishment.

To combine the atmospheric period of the foam with the stable atmospheric, its staller day is stated by the International Foam Resistance and Resistance Vehicle System (IERS), which has been used by the term "UT1 Minutes" in terms of "Satural Suntime Minutes" in the atmospheric time (UT1) or the atmospheric time of these signs. — The atmospheric period of the earth is an estimated change or the atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric.

In the SI minutes 1623–2005 — the scope in the end.

And the average solar time for the periods 1962-2005 will be obtained from IERS.

|USEFUL CONSTANTS|
|This table undergoes permanent improvements and adds. Any
suggestion are welcome, please send it to christian.bizouard[at]obspm.fr.
Thanks to Pr. "Sonny" Mathews (Madras) for his help.
|
Updated March 13 2021
|
Earth's rotation | Geodesy
| Gravity | Cosmology | Physics
| Conversion of units |
|Constant||Symbol|| Value
|
(Uncertainty on the last digits are indicated in parentheses)
|Units|| Relative
|
uncertainty
in 10-6 (ppm)
|Sources - Remarks|
|Earth's rotation constants|
|Mean angular velocity of the Earth||Ω||7.292 115 0(1)||10-5 rad/s||0.014|| IERS Numerical Standards
|
(IAG 1999).
|Nominal angular velocity of the Earth||ΩN||7.292 115 146 706 4||10-5 rad/s||exact||Reference angular velocity corresponding to the epoch 1820|
|Conventional duration of the mean solar day||D||86 400||s||exact||Corresponds to the duration of the mean solar day in the first mid of the nineteen century; presently the mean solar day (the seasonal variation is removed) exceeds 86400 s by about 0.2 ms.|
|Ratio mean solar day/sidereal day||k||1.002 737 909 350 795||-||exact||Aoki et al, 1982, "The New definition of Universal Time", Astron. Astrophys., 105, 359-361 (1982)|
|Conventional duration of the sidereal day||DS=D/k||86164.090 530 832 88||s||exact||from k given in Aoki et al, 1982, "The New definition of Universal Time", Astron. Astrophys., 105, 359-361 (1982)|
|Ratio mean solar day/stellar day||k'|
1.002 737 811 911 354 48
|-||exact||IERS Conventions (2003). Value consistent with the nominal Earth angular velocity ΩN|
|Stellar day||D/k'=2 π/ΩN||86164.098 903 691||s||exact||From k'. The stellar day referred to the stars is not affected by the precession and therefore is slightly larger than the sidereal day|
|General precession in longitude||p||5028.792(2)||" per century||0.4||from MHB 2000 nutation model|
|Obliquity of the ecliptic for the epoch J2000.0||ε0|| 23°26'21".4119
|
(sin ε0=0.397776995)
|-||exact||Definition constant (IAU 1976)|
|Chandler frequency (in the terrestrial frame)||FC||0.8433(30)||cycle per tropical year||4000||Vicente, R.O., Wilson 1997, C.R., JGR, Vol. 102, B9, pp 20439-20446|
|Chandler period (in the terrestrial frame)||TC||433.1(1.7)||mean solar day D||4000||id|
|Quality factor of Chandler peak||QC||170||-||-||Wilson and Vicente, 1980, Geophys. J. R. Astr. Soc., 62, 605-616.|
|Free Core Nutation (FCN) period (in the celestial frame)||TF||430.2(3)||mean solar day D||700||Nutation model MHB 2000|
|Quality factor of the FCN||QF||20000||-||-||Nutation model MHB 2000|
|Sidereal year||-|| 365.256 363 004
|
(365d 6h 9m 9.76s)
| mean solar day
|
[D=86400s]
|From the mean longitude referred to the mean ecliptic and the equinox J2000 given in Simon et al., 1994, Astron. Astrophys., 282, 663|
|Tropical year||-|| 365.242 190 402
|
(365d 5h 48m 45.25s)
|mean solar day [D=86400s]||From the mean longitude referred to the mean ecliptic and the equinoxof the date given in Simon et al., 1994, Astron. Astrophys., 282, 663|
|Mean motion of the Moon||-||2π / 27.32166155(1)||rad/mean solar day [=86400s]||IERS Conventions 2003|
|Geodetic constants|
|Earth's equatorial radius||a||6 378 136.6(1)||m||0.015|| IERS Numerical Standards
|
(IAG 1999)
|First equatorial moment of inertia||A||8.010 1(2)||1037 kg m2||25|
|8.010 082 9(84)||1037 kg m2||0.1||Chen & Shen (2010) Tab 2a|
|Second equatorial moment of inertia||B||8.010 3(2)||1037 kg m2||25||IAG 1999|
|8.010 259 4(84)||1037 kg m2||0.1||Chen & Shen (2010) Tab 2a|
|Mean equatorial moment of inertia||A=(A+B)/2||8.010 171 1(84)||Chen & Shen (2010) Tab 2a|
|Axial moment of inertia||C|
8.0365(2)
|1037 kg m2||25||IAG 1999|
8.0364807(84)
|1037 kg m2||0.1||Chen & Shen (2010) Tab 2a|
|Longitude of the principal inertia axis A||λA||-14.9291(10)||°||100||IAG 1999|
|−14.928509(75)||°||5||Chen & Shen (2010) Tab 2b|
|Colatitude of the principal inertia axis A||θA||0.00003788(48)||°||20000||Chen & Shen (2010) Tab 2b|
|First equatorial moment of inertia of the core||Af||9.115 237 9
||1036 kg m2||Chen & Shen (2010) Tab 3|
|Second equatorial moment of inertia of the core||Bf||9.115 399 7||1036 kg m2||Chen & Shen (2010) Tab 3|
|Axial moment of inertia of the core||Cf||9.139 353 0||1036 kg m2||Chen & Shen (2010) Tab 3|
|First equatorial moment of inertia of the mantle||Am = A-Af||7.016 5||1037 kg m2||?||Barnes et al, 1983, Proc. R. Soc. Lond., A 387, 31-73|
|7.098 56||1037 kg m2||Chen & Shen (2010)|
|Second equatorial moment of inertia of the core||Bm=B-Bf||7.098 72||Chen & Shen (2010)|
|Axial moment of inertia of the mantle||Cm=C-Cf||7.040 0||1037 kg m2||?||Barnes et al, 1983, Proc. R. Soc. Lond., A 387, 31-73|
|7.122 55||1037 kg m2||Chen & Shen (2010)|
|Earth flattening||f||1/298.25642(1)||-||0.03|| IERS Numerical Standards
|
(IAG 1999)
|"Astronomical" dynamical ellipticity||H||3.2737949(1) 10-3||-||0.03|| H=(C-A)/C
|
Nutation model MHB 2000
|Dynamical ellipticity||e=(C - A)/A|
3.284 547 9(1) 10-3
|-||0.0||Nutation model MHB 2000|
|3.284 517 8 10-3||Chen & Shen (2010) Tab. 4|
|Dynamical ellipticity of the core||ef=(Cf - Af)/Af||2.646(2) 10-3||-||750||Nutation model MHB 2000|
|2.645 575 8 10-3||Chen & Shen (2010) Tab. 4|
|Second degree term in Earth's gravity potential||J2||1.082 635 9(1) 10-3||-||0.09|| IERS Numerical Standards
|
(IAG 1999)
J2=-(A+B-2C)/(2MR2)
|Secular rate of J2||d( J2 )/dt||-2.6(3)||10-11 year-1||115000||IAG 1999|
|Love number||k2||0.3||-||-||IAG 1999|
|Secular Love number||ks||0.9383||-||-||IAG 1999|
|Gravitational constants|
|Mean equatorial gravity||g||9.780 327 8 (10)||m s-2||0.1||recommended by CODATA (july 2000)|
|Gravitational constant||G||6.673 84(80)||10-11 m3kg-1s-2||100||recommanded by CODATA 2010|
|G||6.675 59(27)||10-11 m3kg-1s-2||40||Quinn et al., Phys. Rev. Lett. 87 (2001)|
|Geocentric constant of gravitation||GM||3.986 004 418(8)||1014 m3s-2||0.002|| IERS numerical standard
|
(IAG1999)
|Heliocentric constant of gravitation||GS||1.327 124 420 76(50)||1020 m3s-2||0.0004|| IERS numerical standard
|
(from Standish, 1998)
|Mass Moon/ Mass Earth||µ||0.012 300 038 3(5)||-||0.04|| IERS numerical standard
|
(from Standish, 1998)
|Cosmological constant|
|Hubble constant||H||73 (3)||km s-1Mpc-1||41095||recommanded by CODATA 2006|
|Hubble length||R = c/H||1.27(5) 1026||m||41095||recommanded by CODATA 2006|
|Age of the Universe||t0||13.73(15)||Giga year||10924||recommanded by CODATA 2006|
|Physical constants from http://physics.nist.gov/cuu/Constants/index.html recommended by CODATA 2010|
|Speed of light in ether or so-called vacuo||c||299 792 458||ms-1||(by definition)||CODATA|
|permeability of the free space||μ0||4 π 10-7||NA-2||(exact)||CODATA|
|= 12.566 370 614...||10-7 NA-2||(calculated)||CODATA|
|permittivity of the free space||ε0||1/(μ0 c2) =8.854 187 817||10-12 Fm-1||(calculated)||CODATA|
|Gravitational constant||G||6.673 84(80)||10-11 m3kg-1s-2||100||CODATA|
|Planck constant||h||6.626 069 57(29)||10-34 Js||0.05||CODATA|
|h/2π||1.054 571 726(47)||10-34 Js||0.05||CODATA|
|Electron charge||e||1.602 176 565(35)||10-19 C||0.025||CODATA|
|Electron mass||me||9.109 382 91(40)||10-31 kg||0.05||CODATA|
|Proton mass||mp||1.672 621 777(74)||10-27 kg||0.05||CODATA|
|Ratio masses proton-electron||mp/me||1836.152 672 45(75)||0.0004||CODATA|
|Fine-structure constant||a||7.297 352 5698(24)||10-3||0.0003||CODATA|
|Inverse of the fine- struture constant||a-1||137.035 999 074(44)||0.0003||CODATA|
|Avogadro number||NA, L||6.022 141 29(27)||1023 mol-1||0.04||CODATA|
|Boltzmann constant, R/ NA||k||1.380 6488(13)||10-23 JK-1||0.9||CODATA|
|Stefan-Boltzmann constant||σ||5.670 373(21)||10-8 Wm-2K-4||4||CODATA|
|Units and conversion of units|
|1 astronomical unit||UA||149 597 870.691(6)||km||0.00004||numerical IERS Standards|
|From milliarcseconds (mas) to radians||1 mas =4.8481(1) 10-9 rad|
|What represents an arc of 1mas from the center of the Earth at distance equal to the polar radius (6 356 755 m)?||3.1(1) cm|
|Conversion of arc units in hour, minute, second to arc units in degre, arcminute, arcsecond|
24 h = 360° 1 h = 15°
|From modified julian (MJD) day to "julian" year (JY)||JY=2000-(51544.5-MJD)/365.25|
|From modified julian (MJD) day to besselian year (BJ)||BY=2000-(51544.33 3981-MJD)/365.242 198 781 (SOFA)|
|From julian year (JY) to modified julian date (MJD)||MJD=(JY - 2000) * 365.25 + 51544.5|
Chen Shen (2010), New estimates of the inertia tensor and rotation of the triaxial nonrigid Earth, JGR 115, B12419, doi:10.1029/2009JB007094, 2010

புவியின் சுழற்சிக் காலத்தை நிலையான விண்மீன்களுடன் ஒப்பிடுவதை, அதன் ஸ்டெல்லர் நாள் என சர்வதேச புவி சுழற்சி மற்றும் ஒப்பிடு காரணி அமைப்பு (IERS) கூறுகிறது, இது சராசரி சூரிய நேரத்தில் (UT1) அல்லது இந்த எண்களின் மூலத்தில், "சராசரி சூரிய நேர நிமிடங்கள்" என்பதற்குப் பதிலாக "UT1 நிமிடங்கள்" என்ற சொற்றொடர் பயன்படுத்தப்பட்டுள்ளது.— பூமியின் சுழற்சிக் காலத்தை அதன் ஈர்ப்பு விசையால் உந்தப்பட்ட மாற்றம் அல்லது சராசரி வெர்னல் இஃகுவினாக்ஸ் உடன் ஒப்பிடுவதை, ஒரு விண்மீன் நாள் என தவறாக பெயரிடப்பட்டது, இது சராசரி சூரிய நேரம் (UT1) ஆகும். எனவே ஒரு விண்மீன் நாள் ஸ்டெல்லர் நாளை விட 8.4 ms. சிறியது.

SI நிமிடங்களில் 1623–2005—இறுதியில் உள்ள வரைபடம்.

மற்றும் 1962–2005 காலங்களுக்கு சராசரி சூரிய நேரம் IERS -லிருந்து கிடைக்கப் பெறும்.

To combine the atmospheric period of the foam with the stable atmospheric, its staller day is stated by the International Foam Resistance and Resistance Vehicle System (IERS), which has been used by the term "UT1 Minutes" in terms of "Satural Suntime Minutes" in the atmospheric time (UT1) or the atmospheric time of these signs. — The atmospheric period of the earth is an estimated change or the atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric. In the SI minutes 1623–2005 — the scope in the end. And the average solar time for the periods 1962-2005 will be obtained from IERS.

To combine the atmospheric period of the foam with the stable atmospheric, its staller day is stated by the International Foam Resistance and Resistance Vehicle System (IERS), which has been used by the term "UT1 Minutes" in terms of "Satural Suntime Minutes" in the atmospheric time (UT1) or the atmospheric time of these signs. — The atmospheric period of the earth is an estimated change or the atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric atmospheric.

In the SI minutes 1623–2005 — the scope in the end.

And the average solar time for the periods 1962-2005 will be obtained from IERS.

The cave passes approximately 365.2564 million km/h in its cave around the Earth in solar days or a sidereal year. Thus the sun appears to rise at 1° a day or the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time.

கோளப்பாதையில்

நட்சத்திரங்களை

ஒப்பிடுகையில்

நாளொன்றுக்கு

வந்தடைகின்றது

Mass (1024 kg) 5.9722 Volume (1010 km3) 108.321 Equatorial radius (km) 6378.137 Polar radius (km) 6356.752 Volumetric mean radius (km) 6371.000 Core radius (km) 3485 Ellipticity (Flattening) 0.003353 Mean density (kg/m3) 5513 Surface gravity (m/s2) 9.798 Surface acceleration (m/s2) 9.780 Escape velocity (km/s) 11.186 GM (x 106 km3/s2) 0.39860 Bond albedo 0.306 Geometric albedo 0.434 V-band magnitude V(1,0) -3.99 Solar irradiance (W/m2) 1361.0 Black-body temperature (K) 254.0 Topographic range (km) 20.4 Moment of inertia (I/MR2) 0.3308 J2 (x 10-6) 1082.63 Number of natural satellites 1 Planetary ring system No
Semimajor axis (106 km) 149.598 Sidereal orbit period (days) 365.256 Tropical orbit period (days) 365.242 Perihelion (106 km) 147.095 Aphelion (106 km) 152.100 Mean orbital velocity (km/s) 29.78 Max. orbital velocity (km/s) 30.29 Min. orbital velocity (km/s) 29.29 Orbit inclination (deg) 0.000 Orbit eccentricity 0.0167 Sidereal rotation period (hrs) 23.9345 Length of day (hrs) 24.0000 Obliquity to orbit (deg) 23.44 Inclination of equator (deg) 23.44
Semimajor axis (AU) 1.00000011 Orbital eccentricity 0.01671022 Orbital inclination (deg) 0.00005 Longitude of ascending node (deg) -11.26064 Longitude of perihelion (deg) 102.94719 Mean Longitude (deg) 100.46435
Right Ascension: 0.00 - 0.641T Declination : 90.00 - 0.557T Reference Date : 12:00 UT 1 Jan 2000 (JD 2451545.0) T = Julian centuries from reference date
Model GSFC-1283 Dipole field strength: 0.306 Gauss-Re3 Dipole offset: 0.076 Re Surface (1 Re) field strength: 0.24 - 0.66 Gauss Geomagnetic Poles - Model WMM2020 Geocentric Dipole: 80.65 N, 72.68 W Magnetic North Pole: 86.50 N, 164.04 E
Re denotes Earth model radius, here defined to be 6,378 km
Surface pressure: 1014 mb Surface density: 1.217 kg/m3 Scale height: 8.5 km Total mass of atmosphere: 5.1 x 1018 kg Total mass of hydrosphere: 1.4 x 1021 kg Average temperature: 288 K (15 C) Diurnal temperature range: 283 K to 293 K (10 to 20 C) Wind speeds: 0 to 100 m/s Mean molecular weight: 28.97 Atmospheric composition (by volume, dry air): Major : 78.08% Nitrogen (N2), 20.95% Oxygen (O2), Minor (ppm): Argon (Ar) - 9340; Carbon Dioxide (CO2) - 415 Neon (Ne) - 18.18; Helium (He) - 5.24; CH4 - 1.7 Krypton (Kr) - 1.14; Hydrogen (H2) - 0.55 Numbers do not add up to exactly 100% due to roundoff and uncertainty Water is highly variable, typically makes up about 1%
Planetary Fact Table
- metric units
Planetary Fact Table - U.S. units
Planetary Fact Table - Earth ratio

Question: how fast does the cave pass around the earth in solar days

365.2564 சூரிய நாட்களில் 150 மில்லியன் கி.மீ

The cave passes approximately 365.2564 million km/h in its cave around the Earth in solar days or a sidereal year. Thus the sun appears to rise at 1° a day or the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time.

how fast does the cave pass around the earth in solar days

Question: how long does the moon rise in the same time as the sun

how long does the moon rise in the same time as the sun

Question: how long does it take for the moon to rise

how long does it take for the moon to rise

Question: how many hours does the moon rise in the same time

how many hours does the moon rise in the same time

Question: how many degrees does the sun rise in a day

how many degrees does the sun rise in a day

Question: how many kilometers does the cave pass around the earth per second

365.2564 சூரிய நாட்களில் 150 மில்லியன்

how many kilometers does the cave pass around the earth per second

Question: how often does the sun rise in the cave

The cave passes approximately 365.2564 million km / h in its cave around the Earth in solar days or a sidereal year . Thus the sun appears to rise at 1 ° a day or the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time .

கோளப்பாதை பூமி சூரியனைச் சுற்றி தன் கோளப்பாதையில் சராசரியாக 365.2564 சூரிய நாட்களில் 150 மில்லியன் கி.மீ. அல்லது ஒரு விண்மீன் ஆண்டை (sidereal year) கடக்கின்றது. இதனால் சூரியன், நட்சத்திரங்களை ஒப்பிடுகையில் கிழக்கு நோக்கி நாளொன்றுக்கு 1° நகர்வதாக அல்லது சூரியன் அல்லது சந்திரன் விட்டத்தை 12 மணி நேரத்தில் கடப்பதாகத் தோன்றுகிறது. இந்தச் செயலால் சராசரியாக ஒரு சூரிய நாள் அல்லது 24 மணி நேரத்தில் பூமி தன் அச்சிலேயே ஒருமுறை சுழன்று சூரியன் அதன் ஆரம்ப நிலை மெரிடியனை வந்தடைகின்றது.

கோளப்பாதை பூமி சூரியனைச் சுற்றி தன் கோளப்பாதையில் சராசரியாக 365.2564 சூரிய நாட்களில் 150 மில்லியன் கி.மீ. அல்லது ஒரு விண்மீன் ஆண்டை (sidereal year) கடக்கின்றது. இதனால் சூரியன், நட்சத்திரங்களை ஒப்பிடுகையில் கிழக்கு நோக்கி நாளொன்றுக்கு 1° நகர்வதாக அல்லது சூரியன் அல்லது சந்திரன் விட்டத்தை 12 மணி நேரத்தில் கடப்பதாகத் தோன்றுகிறது. இந்தச் செயலால் சராசரியாக ஒரு சூரிய நாள் அல்லது 24 மணி நேரத்தில் பூமி தன் அச்சிலேயே ஒருமுறை சுழன்று சூரியன் அதன் ஆரம்ப நிலை மெரிடியனை வந்தடைகின்றது.

The cave passes approximately 365.2564 million km/h in its cave around the Earth in solar days or a sidereal year. Thus the sun appears to rise at 1° a day or the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time.

The cave passes approximately 365.2564 million km/h in its cave around the Earth in solar days or a sidereal year. Thus the sun appears to rise at 1° a day or the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time as the sun or moon rise at 12 hours in the same time.

The Earth's Milky Way galaxy is located in the mountains of the Earth's Milky Way galaxy in 28,000 light years.

Currently, the equatorial plane is located 20 light years from the orion spiral arm (Orion spiral arm).

அமைந்துள்ளது

நடுதட்டிலிருந்து

அமைந்துள்ளது

Ask an Astrophysicist
This is the "Ask an Astrophysicist" service of the Imagine the Universe! web site. We are a small group of volunteers who work on space-based astronomical observations, including cosmic-ray, gamma-ray, and X-ray astrophysics. Our research subjects are often exotic, like black holes, dark matter, and the origin of the universe.
We have already answered many questions, and have an extensive archive of past questions and answers. Please consult the archive first to see if your question has already been answered. We attempt to answer as many questions as possible, but we are a small group of volunteers and cannot afford the time to answer all the incoming questions.
We will not respond to questions whose answers may be found in our archive or on our site, or questions unrelated to space-based astrophysics.
- We do not accept more than 1 question per email and no more than 1 question per week from an individual user.
- Educators, please see Special Guidelines for Teachers.
- It usually takes 1-2 weeks for our volunteers to answer a question.
Which topic area are you interested in?
(Please select one to search for the answer to your question)
♦ General Astronomy & Astrophysics *
Please Note: Topic links with * next to them take you to an archive of questions & answers and other resources, but will not allow you to submit new questions.
Not sure where your question fits in? If so,
- Read an explanation of these topic areas.
- Or type a key word or phrase into our LIBRARY SEARCH ENGINE --- your question may already have been answered on our site.
If your question does not fall onto one of the above areas, it means we are not the appropriate resource for your question.
- Check out the "Who are we" page, which explains what we study, what questions we'd most like to answer, and how we fit in with the rest of NASA.
- You can find other similar services by doing a web search for them or you could try doing a general web search for your question --- a lot of the things are on the web, if only you knew where to look. Here is an explanation of how to do a web search.

Question: how far is the equatorial plane from the orion spiral arm

20 ஒளி ஆண்டுகள்

The Earth's Milky Way galaxy is located in the mountains of the Earth's Milky Way galaxy in 28,000 light years.

Currently, the equatorial plane is located 20 light years from the orion spiral arm (Orion spiral arm).

how far is the equatorial plane from the orion spiral arm

Question: how long is the milky way galaxy

28,000 ஒளி ஆண்டுகளில்

Question: what is another name for the spiral arm

ஓரியன் மண்டலத்தின் சுழல் கையிலும் ( Orion spiral arm

Question: what is another name for the orion spiral arm

what is another name for the orion spiral arm

Question: how many light years is the equatorial plane from the orion spiral arm

how many light years is the equatorial plane from the orion spiral arm

Question: how many light years is the milky way galaxy

how many light years is the milky way galaxy

Question: which plane is 20 light years from the orion spiral arm

which plane is 20 light years from the orion spiral arm

Question: where is the milky way galaxy located

The Earth 's Milky Way galaxy is located in the mountains of the Earth 's Milky Way galaxy in 28,000 light years .

Currently , the equatorial plane is located 20 light years from the orion spiral arm ( Orion spiral arm ) .

பூமி சூரிய மண்டலத்தோடு பால்வெளி (Milky Way) கேலக்ஸியில் (galaxy) அதன் மையத்தை 28,000 ஒளி ஆண்டுகளில் சுழலும் பாதையில் அமைந்துள்ளது. இது தற்போது இந்த மண்டலத்தின் நில நடுதட்டிலிருந்து (equatorial plane) 20 ஒளி ஆண்டுகள் மேலேயும் ஓரியன் மண்டலத்தின் சுழல் கையிலும் (Orion spiral arm) அமைந்துள்ளது.

பூமி சூரிய மண்டலத்தோடு பால்வெளி (Milky Way) கேலக்ஸியில் (galaxy) அதன் மையத்தை 28,000 ஒளி ஆண்டுகளில் சுழலும் பாதையில் அமைந்துள்ளது. இது

தற்போது இந்த மண்டலத்தின் நில நடுதட்டிலிருந்து (equatorial plane) 20 ஒளி ஆண்டுகள் மேலேயும் ஓரியன் மண்டலத்தின் சுழல் கையிலும் (Orion spiral arm) அமைந்துள்ளது.

The Earth's Milky Way galaxy is located in the mountains of the Earth's Milky Way galaxy in 28,000 light years. Currently, the equatorial plane is located 20 light years from the orion spiral arm (Orion spiral arm).

The Earth's Milky Way galaxy is located in the mountains of the Earth's Milky Way galaxy in 28,000 light years.

Currently, the equatorial plane is located 20 light years from the orion spiral arm (Orion spiral arm).

When seen from the sunlight, the moon will find the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth.

The cold season will occur on 21 December, the cold season will occur on 21 June, the convenience will occur on 20 March, the convenience will occur on 23 September, the convenience will occur on 23 September.

விண்வெளியிலிருந்து காணும் போது, சந்திரன் வெவ்வேறு தோற்றங்களை பெறுவதைப் போல பூமியும் மாறுபட்ட தோற்றங்களை பெறுவதைக் காணலாம். வானியல் மரபுப்படி, நான்கு பருவ காலங்களும், புவி தனது கோளப் பாதையில் சூரியனை நோக்கி அல்லது சூரியனிலிருந்து விலகும் அதிகபட்ச அச்சு சாய்வுப் புள்ளியான சால்ஸ்டிஸ் (solstice) என்பதையும், இஃவினாக்ஸ் (equinox) சாயும் திசை சூரியனை நோக்கிச் செங்குத்தாக இருக்குமானால், இவை இரண்டையும் வைத்து நிர்ணயிக்கப்படுகிறது. குளிர் கால சால்ஸ்டிஸ் டிசம்பர் 21 அன்று ஏற்படும், கோடை கால சால்ஸ்டிஸ் ஜூன் 21 தேதி வாக்கில் ஏற்படும், வசந்தகால இஃவினாக்ஸ் மார்ச் 20 ஆம் தேதி வாக்கில் ஏற்படும், இலையுதிர்கால இஃவினாக்ஸ் செப்டம்பர் 23 ஆம் தேதி வாக்கில் ஏற்படும்.

விண்வெளியிலிருந்து காணும் போது, சந்திரன் வெவ்வேறு தோற்றங்களை பெறுவதைப் போல பூமியும் மாறுபட்ட தோற்றங்களை பெறுவதைக் காணலாம். வானியல் மரபுப்படி, நான்கு பருவ காலங்களும், புவி தனது கோளப் பாதையில் சூரியனை நோக்கி அல்லது சூரியனிலிருந்து விலகும் அதிகபட்ச அச்சு சாய்வுப் புள்ளியான சால்ஸ்டிஸ் (solstice) என்பதையும், இஃவினாக்ஸ் (equinox) சாயும் திசை சூரியனை நோக்கிச் செங்குத்தாக இருக்குமானால், இவை இரண்டையும் வைத்து நிர்ணயிக்கப்படுகிறது.

குளிர் கால சால்ஸ்டிஸ் டிசம்பர் 21 அன்று ஏற்படும், கோடை கால சால்ஸ்டிஸ் ஜூன் 21 தேதி வாக்கில் ஏற்படும், வசந்தகால இஃவினாக்ஸ் மார்ச் 20 ஆம் தேதி வாக்கில் ஏற்படும், இலையுதிர்கால இஃவினாக்ஸ் செப்டம்பர் 23 ஆம் தேதி வாக்கில் ஏற்படும்.

When seen from the sunlight, the moon will find the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth. The cold season will occur on 21 December, the cold season will occur on 21 June, the convenience will occur on 20 March, the convenience will occur on 23 September, the convenience will occur on 23 September.

When seen from the sunlight, the moon will find the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth and the earth will receive the earth.

The cold season will occur on 21 December, the cold season will occur on 21 June, the convenience will occur on 20 March, the convenience will occur on 23 September, the convenience will occur on 23 September.

When seen from the foam, the trees even stumble in a few meters distance of exhibition.

As many of these districts are characterized by this district, many of these districts are defined as part-time districts.

This city has a period of 14 months with a period of one year, it is referred to as a sandal period. The earth's flow rate is also affected by the fact that the time changes.

"புவியிலிருந்து

மேற்பரப்பில்

அடங்கியதாகும்

என்றழைக்கப்படுகின்றது

குறிப்பிடுகின்றனர்

பாதிக்கப்படுகின்றது

|
|
Charlottesville
Events
Internal
Maps and Directions
Other NRAO Sites
NRAO Telescopes
|
|
|
|
Charlottesville, Virginia
The NRAO's Charlottesville operations are located in
Stone Hall, at Edgemont Road on the grounds of the University of Virginia, and
in the NRAO Technology Center on Ivy Road.
|
||
NRAO Headquarters and North American ALMA Science
Center
|
The Director's Office, the North American ALMA Science
Center (NAASC), NRAO
administrative offices, and the main
NRAO Library are located in Stone
Hall, not far
from the University of Virginia's Department of Astronomy.
Stone Hall has recently undergone a major
renovation and addition.
The NAASC and the NRAO Research Library are the primary
beneficiaries of this expansion.
|
|
|
NRAO Technology Center
|
The NRAO Technology Center (NTC) includes
the
Central Development Laboratory (CDL) and the
ALMA Electronics Division. The CDL
develops and builds key components for ALMA, the
VLA, VLBA, GBT, EVLA, as well as other projects and
activities.
The ALMA Electronics Division is responsible for
the design, prototyping, and
fabrication of many of the electronic components which will enable ALMA
to receive and process the signals received from the cosmos.
|
|
|
|
EMERGENCY - CV Facility Information Number 434-296-0200

Question: what is the period of 14 months with one year called

When seen from the foam, the trees even stumble in a few meters distance of exhibition.

As many of these districts are characterized by this district, many of these districts are defined as part-time districts.

This city has a period of 14 months with a period of one year, it is referred to as a sandal period. The earth's flow rate is also affected by the fact that the time changes.

what is the period of 14 months with one year called

Question: how long does the sandal period last

Question: how long is the sandal period

Question: how many months does the sandal period last

how many months does the sandal period last

Question: many of these districts are defined as what

பகுதி கால நகர்தல்

many of these districts are defined as what

Question: what is the source of the trees in this district

"புவியிலிருந்து

what is the source of the trees in this district

Question: what is affected by the time changes

பூமியின் சுழல் வேகமும்

Question: how far away are the trees from the foam

how far away are the trees from the foam

When seen from the foam , the trees even stumble in a few meters distance of exhibition .

As many of these districts are characterized by this district , many of these districts are defined as part - time districts .

This city has a period of 14 months with a period of one year , it is referred to as a sandal period . The earth 's flow rate is also affected by the fact that the time changes .

புவியிலிருந்து காணும் போது, துருவங்கள் கூட சில மீட்டர் தூரம் மேற்பரப்பில் நகர்கிறது. இந்த துருவ நகர்தல் பல சுழற்சி பகுதிகள் அடங்கியதாகும், இந்த பல பகுதிகள் மொத்தமாக பகுதி கால நகர்தல் என்றழைக்கப்படுகின்றது. இந்த நகர்தலுக்கு ஒரு வருட சுற்றோடு 14 மாத சுற்றும் உள்ளது, அதை சாண்ட்லேர் தள்ளாட்டம் என குறிப்பிடுகின்றனர். பூமியின் சுழல் வேகமும் தின நேர மாற்றம் என்ற செயலால் பாதிக்கப்படுகின்றது.

புவியிலிருந்து காணும் போது, துருவங்கள் கூட சில மீட்டர் தூரம் மேற்பரப்பில் நகர்கிறது.

இந்த துருவ நகர்தல் பல சுழற்சி பகுதிகள் அடங்கியதாகும், இந்த பல பகுதிகள் மொத்தமாக பகுதி கால நகர்தல் என்றழைக்கப்படுகின்றது.

இந்த நகர்தலுக்கு ஒரு வருட சுற்றோடு 14 மாத சுற்றும் உள்ளது, அதை சாண்ட்லேர் தள்ளாட்டம் என குறிப்பிடுகின்றனர். பூமியின் சுழல் வேகமும் தின நேர மாற்றம் என்ற செயலால் பாதிக்கப்படுகின்றது.

When seen from the foam, the trees even stumble in a few meters distance of exhibition. As many of these districts are characterized by this district, many of these districts are defined as part-time districts. This city has a period of 14 months with a period of one year, it is referred to as a sandal period. The earth's flow rate is also affected by the fact that the time changes.

When seen from the foam, the trees even stumble in a few meters distance of exhibition.

As many of these districts are characterized by this district, many of these districts are defined as part-time districts.

This city has a period of 14 months with a period of one year, it is referred to as a sandal period. The earth's flow rate is also affected by the fact that the time changes.

In the end of the sunshine, the sun will be 106.9% of the sunshine coming from the sunshine, the sun will be 106.9% of the sunshine coming from the sunshine.

When the earth is very close to the sun, the sun is very close to the sun, and when the sun is very close to the sun, the sun is very close to the sun, and when the sun is very close to the sun, the sun is very close to the sun.

But the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere.

வீச்சிலிருந்து

வீச்சிலிருந்து

ஆற்றலிலிருந்து

ஒப்பிடுகையில்

கிடைக்கின்றது

|
|
Earth's tilt creates seasons
By Jack Williams, USATODAY.com
The reason for changes in Earth's
seasons is the Earth's tilt, not its distance from the sun.
More information:
In the Northern Hemisphere summer,
the land north of the equator is tilted towards the sun, allowing more of the
sunís energy to heat the Northern Hemisphere.
Conversely, during the Northern
Hemisphere winter, the land north of the equator is tilted away from the sun,
which lowers the amount of the sunís energy warming the Northern Hemisphere.
The Earth is actually closer
to the sun during the Northern Hemisphere winter, but since the hemisphere is
tilted away from the sun, it still feels like winter.
In fact, the Earth's average
temperature is actually higher in July, when it's the farthest from the sun.
"Averaged over the globe, sunlight
falling on Earth in July (aphelion) is indeed about 7% less intense than it
is in January (perihelion)," says Roy Spencer of the Global Hydrology and
Climate Center in Huntsville, Alabama. Still, "the average temperature
of Earth at aphelion is about 4 degrees F (2.3 degrees C) higher than it is
at perihelion."
Why is the Earth warmer when
we're farther from the sun?
It's because there's more land
in the Northern Hemisphere and more water in the south. During July the land-crowded
northern half of our planet is tilted toward the sun. Land warms faster than
the water. "Earth's temperature (averaged over the entire globe) is slightly
higher in July because the sun is shining down on all that land, which heats
up rather easily," says Spencer.
This is explained in more detail
in a story, Aphelion
Away, on the Science@NASA Web site.

Question: what percentage of the earths sunshine comes from the sun

In the end of the sunshine, the sun will be 106.9% of the sunshine coming from the sunshine, the sun will be 106.9% of the sunshine coming from the sunshine.

When the earth is very close to the sun, the sun is very close to the sun, and when the sun is very close to the sun, the sun is very close to the sun, and when the sun is very close to the sun, the sun is very close to the sun.

But the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere.

what percentage of the earths sunshine comes from the sun

Question: how much of the sun does the earth get at the end of the day

106.9% of the sunshine coming from the sunshine

வீச்சிலிருந்து வரும் கதிர்வீச்சு , சூரிய பெரும வீச்சிலிருந்து வரும் ஆற்றலிலிருந்து 106.9 % மாக இருக்கும் . வேறுபாடு உள்ளது .

106.9 % of the sunshine coming from the sunshine

how much of the sun does the earth get at the end of the day

Question: when the earth is very close to the sun, what happens

அதன் தென் துருவம் சூரியனை நோக்கி இருப்பதால் அதற்கு சூரிய சக்தி வட துருவத்தை ஒப்பிடுகையில் ஒரு வருடத்தில்

when the earth is very close to the sun, what happens

Question: when the earth is very close to the sun what happens

அதன் தென் துருவம் சூரியனை நோக்கி இருப்பதால் அதற்கு சூரிய சக்தி வட துருவத்தை ஒப்பிடுகையில் ஒரு வருடத்தில்

when the earth is very close to the sun what happens

Question: when the earth is very close to what does the earth close to

சூரிய சிறும வீச்சிலிருந்து வரும் கதிர்வீச்சு

when the earth is very close to what does the earth close to

In the end of the sunshine , the sun will be 106.9 % of the sunshine coming from the sunshine , the sun will be 106.9 % of the sunshine coming from the sunshine .

When the earth is very close to the sun , the sun is very close to the sun , and when the sun is very close to the sun , the sun is very close to the sun , and when the sun is very close to the sun , the sun is very close to the sun .

But the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere .

இன்வர்ஸ் ஸ்குயர் விதியால், சூரிய சிறும வீச்சிலிருந்து வரும் கதிர்வீச்சு, சூரிய பெரும வீச்சிலிருந்து வரும் ஆற்றலிலிருந்து 106.9% மாக இருக்கும். வேறுபாடு உள்ளது. பூமி சூரியனின் மிக அருகே செல்லும் போது அதன் தென் துருவம் சூரியனை நோக்கி இருப்பதால் அதற்கு சூரிய சக்தி வட துருவத்தை ஒப்பிடுகையில் ஒரு வருடத்தில் அதிகமாகக் கிடைக்கின்றது. ஆனால் தென் துருவம் இந்த வகையில் அடையும் சக்தி அது புவி அச்சின் சாய்வு மற்றும் அதிக ஆற்றலை உறிஞ்சும் தென் துருவ நீரினால் கிடைக்கும் மொத்த சக்தியை விட மிக குறைவே ஆகும்.

இன்வர்ஸ் ஸ்குயர் விதியால், சூரிய சிறும வீச்சிலிருந்து வரும் கதிர்வீச்சு, சூரிய பெரும வீச்சிலிருந்து வரும் ஆற்றலிலிருந்து 106.9% மாக இருக்கும். வேறுபாடு உள்ளது.

பூமி சூரியனின் மிக அருகே செல்லும் போது அதன் தென் துருவம் சூரியனை நோக்கி இருப்பதால் அதற்கு சூரிய சக்தி வட துருவத்தை ஒப்பிடுகையில் ஒரு வருடத்தில் அதிகமாகக் கிடைக்கின்றது.

ஆனால் தென் துருவம் இந்த வகையில் அடையும் சக்தி அது புவி அச்சின் சாய்வு மற்றும் அதிக ஆற்றலை உறிஞ்சும் தென் துருவ நீரினால் கிடைக்கும் மொத்த சக்தியை விட மிக குறைவே ஆகும்.

In the end of the sunshine, the sun will be 106.9% of the sunshine coming from the sunshine, the sun will be 106.9% of the sunshine coming from the sunshine. When the earth is very close to the sun, the sun is very close to the sun, and when the sun is very close to the sun, the sun is very close to the sun, and when the sun is very close to the sun, the sun is very close to the sun. But the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere.

In the end of the sunshine, the sun will be 106.9% of the sunshine coming from the sunshine, the sun will be 106.9% of the sunshine coming from the sunshine.

When the earth is very close to the sun, the sun is very close to the sun, and when the sun is very close to the sun, the sun is very close to the sun, and when the sun is very close to the sun, the sun is very close to the sun.

But the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere is much less than the power of the sign in this sphere.

Due to the extinction of these spots, the moon runs 38 mm per year away from the Earth.

For more than a few million years, these small changes have caused a number of significant changes, including a year-on-year 23 μs in the day of the Earth's Earth's Earth's Earth's Earth.

வருடத்திற்கு

வருடங்களுக்கு

மாற்றங்களும்

வருடத்திற்கு

குறிப்பிடத்தகுந்த

ஏற்படுத்தியுள்ளன

எடுத்துக்காட்டாக

Question: how far away is the moon from the earth

Due to the extinction of these spots, the moon runs 38 mm per year away from the Earth.

For more than a few million years, these small changes have caused a number of significant changes, including a year-on-year 23 μs in the day of the Earth's Earth's Earth's Earth's Earth.

Question: how many times a year does the moon change in the day of the earth's earth

23 µs வீதம் பூமியின் ஒரு நாள் நீள்வதும்

how many times a year does the moon change in the day of the earth's earth

Question: how many μs are there in the day of the earth's earths earth's

how many μs are there in the day of the earth's earths earth's

Question: how long has the moon been away from earth

"பல மில்லியன் வருடங்களுக்கு

how long has the moon been away from earth

Question: how many mm does the moon run away from the earth

how many mm does the moon run away from the earth

Question: why is the moon 38 mm away from the earth

why is the moon 38 mm away from the earth

Question: why does the moon run 38 mm from the earth

why does the moon run 38 mm from the earth

Due to the extinction of these spots , the moon runs 38 mm per year away from the Earth .

For more than a few million years , these small changes have caused a number of significant changes , including a year - on - year 23 μs in the day of the Earth 's Earth 's Earth 's Earth 's Earth .

இந்தப் பேரலைகள் ஊடாடுவதன் காரணமாக, சந்திரன் பூமியை விட்டு வருடத்திற்கு 38 மி.மீ. விலகிச் செல்கிறது. பல மில்லியன் வருடங்களுக்கு மேலாக, இந்த சிறு மாற்றங்களும்-ஒரு வருடத்திற்கு 23 µs வீதம் பூமியின் ஒரு நாள் நீள்வதும், பல குறிப்பிடத்தகுந்த மாற்றங்களை ஏற்படுத்தியுள்ளன. எடுத்துக்காட்டாக, தேவோனியன் காலத்தின்

இந்தப் பேரலைகள் ஊடாடுவதன் காரணமாக, சந்திரன் பூமியை விட்டு வருடத்திற்கு 38 மி.மீ. விலகிச் செல்கிறது.

பல மில்லியன் வருடங்களுக்கு மேலாக, இந்த சிறு மாற்றங்களும்-ஒரு வருடத்திற்கு 23 µs வீதம் பூமியின் ஒரு நாள் நீள்வதும், பல குறிப்பிடத்தகுந்த மாற்றங்களை ஏற்படுத்தியுள்ளன. எடுத்துக்காட்டாக, தேவோனியன் காலத்தின்

Due to the extinction of these spots, the moon runs 38 mm per year away from the Earth. For more than a few million years, these small changes have caused a number of significant changes, including a year-on-year 23 μs in the day of the Earth's Earth's Earth's Earth's Earth.

Due to the extinction of these spots, the moon runs 38 mm per year away from the Earth.

For more than a few million years, these small changes have caused a number of significant changes, including a year-on-year 23 μs in the day of the Earth's Earth's Earth's Earth's Earth.

In fact, (410 million years ago) a year was 400 days, a day was 21.8 hours.

வருடத்திற்கு

வருடங்களுக்கு

மாற்றங்களும்

வருடத்திற்கு

குறிப்பிடத்தகுந்த

ஏற்படுத்தியுள்ளன

எடுத்துக்காட்டாக

ஆண்டுகளுக்கு

வருடத்திற்கு

===============================================================================
Author: Hannu K. J. Poropudas
Title: Using Coral as a Clock
===============================================================================
APPROXIMATE ANCIENT TIME FORMULA BASED ON FOSSIL DATA
Hannu K. J. Poropudas
(R&D; Engineer, Nokia Telecommunications)
(E-Mail Address: poropuda@tnclus.tele.nokia.fi)
Vesaisentie 9E, 90900 Kiiminki, Finland
ABSTRACT
Time formula, also called fossil formula, gives an answer to the question:
how many mean solar days are in a tropical year at a certain point in time.
It is the simplest possible expression that has been worked out from
experimental fossil points (Eicher/Wells 1976, Pannella MacClintock
Thompson 1968 and Scrutton 1978).
The formula is intended for use mainly in the experimental fossil point's
area, which goes back, at maximum, as far as the approximately 3,556 (+ 0,032)
-
billion years old Warrawoona stromatolite fossils (The Cambridge Encyclopaedia
of Earth Sciences 1982 diagram page 357, Schopf 1983).
At the present, the time formula have been tested over an interval as far
back as 850 (+ 50) million years and consistency with the experimental points
-
looks good (formula's safe area of use).
TIME FORMULA
The time formula is the following expression given over the widest
possible time area. The time area can be limited on the basis of
experimental measurement data, if the deviations of the measured results
are, for example, greater than five to ten days.
2
M - A(T)* T - B(T)* T
N(T) = ---------------------
1 + C(T)* T
N(T) = Number of mean solar days in tropical year at the point T
T = time in uniform centuries
M = 365,2422
Here is taken into account lengthening of measured uniform mean
solar day as a first approximation (Allen 1973).
15 1 -8
1 + C* T = 1 + ----- * ----- * T = 1 + 1,7361 * 10 T
10000 86400
The uniform shortening formula of the tropical year (Allen 1973)
-6
365,24219878 - 6,16 * 10 T
has been corrected by one nonlinear term and also the coefficient of the
linear term has been corrected. As a first approximation the coefficients
A(T) and B(T) are also assumed to be constants.
If (N1, T1) and (N2, T2) are two fossil points and if C(T) is assumed
constant value then the coefficients of the formula have the following
values:
A = T2(M-N1)/T1/(T2-T1) - T1(M-N2)/T2/(T2-T1) + C*(N2T1-N1T2)/(T2-T1)
B = (M-N2)/T2/(T2-T1) - (M-N1)/T1/(T2-T1) + C*(N1-N2)/(T2-T1)
The coefficients of the terms are achieved from two reliable fossil points.
1. From coral fossil data approximately 400 million years ago. It has been
estimated that there were little over 400 days in a year at that time.
These fossil corals were ancient marine invertebrates that secreted
a microscopically thin layer of calsium carbonate each day; the layers laid
down in summer were thicker than those laid down in winter.
Estimations are based on careful countings of calcium carbonate layers in
fossil corals formed due to the changes of lightness of night and day
(The Cambridge Atlas of Astronomy 1985, Pages 55 and 54, Photograph:
J. C. Revy. The specimen is from the collection of the Brittish National
Museum of the Natural History).
2. From fossil data approximately 180 million years ago, when there were
approximately 381 days of that time in a year (Wells 1963).
-6 -13
A = 2,46 * 10 and B = 1,79 * 10 (in first time formula).
If fossil points from (Eicher 1976) are used.
1. From fossil data approximately 190 million years ago, when there were
approximately 382 days of that time in a year (Eicher/Wells 1976).
2. From fossil data approximately 395 million years ago, when there was
approximately 401 days of that time in a year (Eicher/Wells 1976).
then
-6 -14
A = 2,28 * 10 and B = 4,74 * 10 (in second time formula)
(see for basis growth increments in fossils: Rosenberg Runcorn 1975).
This seems to be a good form for the approximation even when C is afterwards
set to depend on T. This new setting is possible because the formula allows
quite wide range of variations of C's magnitude and it still gives a good
fit to the fossil data.
A(T) = T2(M-N1)/T1/(T2-T1) - T1(M-N2)/T2/(T2-T1) + C(T)*(N2T1-N1T2)/(T2-T1)
B(T) = (M-N2)/T2/(T2-T1) - (M-N1)/T1/(T2-T1) + C(T)*(N1-N2)/(T2-T1)
The best C(T) is achieved from Geologic Rock and Fossil Record Data, if
the distance between Earth and Moon can be estimated at different points
on the geologic time scale. Solar tides must also be accounted because
these tides speeds up Earth's rotation (see fossil data of past 500 million
years: Pannella MacClintock and Thompson 1968, and Scrutton 1978, Fig 8,
Page 185).
The coefficient of the asymptotic straight line for the month formula is
-7
about 2,60 * 10 from (Scrutton 1978) and the little uncertain period of
4
oscillation about this line is roughly 429,4 * 10 centuries from
(Pannella MacClintoc and Thompson 1968).
-7 4
P(T) = 29,53 - 2,60 * 10 * ( 1 - e*sin ( 2 P T / (429,4 * 10 )))* T
P(T)= number of mean solar days per synodic month at a certain
point T of time
0 <= e <= 1, (e = 1 in first approximation)
P = 3,14159 radians
(This month formula is not used because it is still under testings).
4
If dT = + 5 * 10 centuries and dN = + 0,5 mean solar days/tropical year
- -
are the accuracy of determination of the absolute age of the fossil samples,
and latter is roughly the accuracy of determination of the number of days in
year from fossil samples, then calculations gives the same order error
magnitudes as A and B themselves are, so at present accuracy the coefficients
cannot be estimated very reliable.
The coral and bivalve fossil data suggests that the value of derivative
of the time formula at the point T = 0 is (Schopf 1983):
-6
-(9,5 + 0,9) * 10 (coral data)
- -6
-(10,0 + 1,2) * 10 (bivalve data)
-
Further data (Schopf 1983):
(d W / dt) / (dW / dt) = 42 + 11 (coral data)
Earth Earth-Moon -
= 46 + 8 (bivalve data)
-
= 51 + 5 (modern astronomical data)
-
= 48 (present day value predicted by Kepler's third law and the
conservation of angular momentum)
TABLE OF CALCULATED VALUES COMPARED WITH THE FOSSIL DATA (FIRST TIME
FORMULA, WELL'S CORAL FOSSIL DATA)
The time formula give the following table with different values of T:
TABLE 1
4
1. = T / 10 (centuries)
2. = calculated value from the first time formula (days/year)
3. = calculated value from the second time formula (days/year)
7. = experimental value (days/year), (Wells 1963). 8. = era (end time).
1. 2. 3. 7. 8.
------------------------------------------------------------------------
0 365,24 365,24 365,24 Cenozoic
------------------------------------------------------------------------
- 65 370,95 370,89 371 Cretaceous
------------------------------------------------------------------------
-135 377,07 377,07 377 Jurassic
------------------------------------------------------------------------
-180 381,00 381,10 381 Triassic
------------------------------------------------------------------------
-230 385,34 385,63 385 Permian
------------------------------------------------------------------------
-280 389,67 390,22 390 Pennsylvanian
------------------------------------------------------------------------
-310 392,26 393,01 393 Mississippian
------------------------------------------------------------------------
-345 395,27 396,28 396 Devonian
------------------------------------------------------------------------
<-405 400,42 401,96 >400
------------------------------------------------------------------------
-405 400,42 401,96 402 Silurian
------------------------------------------------------------------------
-425 402,14 403,88 Ordovician
------------------------------------------------------------------------
-500 408,53 411,15 412 Cambrian
(the fossil can be older)
------------------------------------------------------------------------
-600 416,99 421,08 424 Precambrian
(no fossil evidence)
------------------------------------------------------------------------
-390- 399,14- 400,53->400 Devonian (The Cambridge Atlas of)
-400 400,00 401,48 Astronomy 1985, p.55 and p.54)
------------------------------------------------------------------------
WELL'S CORAL FOSSIL SAMPLES:
TABLE 2
WELL'S CORAL FOSSIL SAMPLES (1. Wells 1963 and 2. Wells 1970):
Era 1. Sample 1. Data 1.
-------------------------------------------------------------------------
Pensylvanian Caninia 385 day layers
-------------------------------------------------------------------------
Pennsylvanian Lophophyllidium 390 day layers
-------------------------------------------------------------------------
Middle-Devonian Heliophyllum halli usually about 400 day layers,
(13 annual growth
increments) ranging between extremes of 385
Eridophyllum archiaci and 410
Favosites
-------------------------------------------------------------------------
Lower-Silurian Holophragma calceoloides
-------------------------------------------------------------------------
Cambrian An estimation= 21-hr Cambrian day
(Munk MacDonald 1960).
Era 2. Sample 2. Data 2.
-------------------------------------------------------------------------
Mississippian Lithostrontion 398 day layers.
-------------------------------------------------------------------------
Mississippian Lophophylldium 380 and 390 day layers.
-------------------------------------------------------------------------
Middle-Devonian Heliophyllum halli average of 398 with a range from
Eridophyllum archiaci 385 to 405.
(Fig. 3.)
Cylindrophyllum
Favosites
-------------------------------------------------------------------------
Middle-Silurian Holophragma calceoloides.
(Fig. 1. and 2.)
-------------------------------------------------------------------------
Middle Silurian Ketophyllum about 400 day layers.
-------------------------------------------------------------------------
Upper Ordovician Streptelasma about 412 day layers.
-------------------------------------------------------------------------
Cambrian Escherichia coli An estimation = 21-hr Cambrian
day (Halberg Conner 1961).
TABLE OF CALCULATED VALUES COMPARED WITH THE FOSSIL DATA, (SECOND TIME
FORMULA, WELL'S CORAL FOSSIL DATA)
The time formula the following table with different values of T:
TABLE 3
7. = experimental value (days/year), (Eicher/Wells 1976).
1. 2. 3. 7. 8.
------------------------------------------------------------------------
0 365,24 365,24 365,24 Cenozoic
------------------------------------------------------------------------
- 65 370,95 370,89 371 Cretaceous
------------------------------------------------------------------------
-136 377,16 377,16 377 Jurassic
------------------------------------------------------------------------
-190 381,87 382,00 382 Triassic
------------------------------------------------------------------------
-225 384,91 385,18 385 Permian
------------------------------------------------------------------------
-280 389,67 390,22 390 Pennsylvanian
------------------------------------------------------------------------
-325 393,55 394,41 394 Mississippian
------------------------------------------------------------------------
-345 395,27 396,28 396 Devonian
------------------------------------------------------------------------
-395 399,57 401,00 401 Silurian
------------------------------------------------------------------------
-435 402,99 404,84 405 Ordovician
------------------------------------------------------------------------
-500 408,53 411,15 412 Cambrian
------------------------------------------------------------------------
-570 414,46 418,07 421 Precambrian
------------------------------------------------------------------------
Three coral species from Middle Devonian rocks of New York and Ontario,
the numerous counts range between 385 and 410 and they accumulate near the
median of 398.
AWRAMIK'S AND VANYO'S STROMATOLITE DATA FROM THE BITTER SPRINGS FORMATION,
(Anabaria Juvensis), CALCULATED AND THE FOSSIL DATA COMPARED
(FIRST AND SECOND TIME FORMULA)
(Vanyo Awramik 1985, error limit of the age determination 50 million years)
This research was supported in part by the NSF Grant EAR 83-03754 and is
contribution no. 145 of the Preston Cloud Research Laboratory.
All samples are in collections of the Preston Cloud Research Laboratory.
TABLE 4
7. = experimental value (days/year), (Vanyo Awramik 1985).
1. 2. 3. 7.
------------------------------------------------------------------------
-850 437,83 447,19 435 (best) or 454 or 409 or 485
------------------------------------------------------------------------
This, approximately 850 million years old, stromatolite
investigated by Vanyo and Awramik had a wavy sinusoidal year growth
"wave length" of 87 mm in the best sample and the depth of a days growth
was 0,2 mm. This gave about 435 days in year at that time. Extreme values
were measured to be 409 and 485, and one measurement gave the value 454.
This wavy nature of the growth is due the point of view that the growth has
been directed towards the Sun and the same direction is repeated annually.
THE STROMATOLITE FROM THE AREA OF GREAT SLAVE LAKE (Hearne Formation) GSM 77325
(Jones 1981 and Schopf 1983, age determination is too inaccurate)
The specimen is stored in the collection of Institute of Geological
Sciences.
TABLE 5
7. = experimental value, Highest count=(days/month) ?,(Jones 1981,
Schopf 1983).
8. = experimental value, Mode=(days/(month/2))-(days/month) ?,
(Jones 1981, Schopf 1983).
9. = experimental value, Tidal cycles per year=( months/year ) ?,
(Pannella 1972 b).
1. 2. 3. 7. 8. 9.
------------------------------------------------------------------------
-1790- 510,60- 567,10-
-2170 536,42 629,58 13
------------------------------------------------------------------------
Pannella has estimated (Pannella 1972 b) that there have been about 13
tidal cycles in a year at that time. He has always counted two groups of
laminae of the stromatolite as a unit. The very clear accumulation in the
magnesium spectrum of the stromatolite laminations at the number 25 remains
unclear.
GSM 77325 spectrum:
Mg: 21-25-(33-34)-44-51-(75-76).
? -------
Si: 5-8-10-17-21-25-(26-28)-(35-36)-(43-45)-54-73-100.
-------
Al: 5-19-21-25-27-29-(30-36)-41-50-53.
----------
Ca: 8-11-17-21-25-27-34-43-46-(50-51)-66-81-101-121.
--
( )= between.
BULAWAYAN STROMATOLITE BUL-6/BUL-7 OR UCLA-BUL-7 OR P.P.P.G 253
(Schopf 1983 , error limit 140 million years, age determination too
inaccurate, see pages 385-413)
The specimen code is P.P.R.G (Precambrian Paleobiology Research Group)
number.
TABLE 6
4
1. = T / 10 (centuries),(Schopf 1983) .
7. = experimental value, Highest count=(days/month)?, (Pannella 1972 a).
8. = experimental value,
Mode=(days/(month/4))-(days/(month/2))-(days/month)?, (Pannella 1972 a).
9. = experimental value, Tidal cycles per year (months/year)?,(important)
1. 2. 3. 7. 8. 9.
------------------------------------------------------------------------
-2460- 556,33- 693,70- 41 10-20-40 ?
-2740 571,69 762,65
------------------------------------------------------------------------
There are very clear growth layers and time marks in the
Bulawayan stromatolite ?
(Pannella 1972 a):
Mode = 10-20-40 and Highest Count = 41 .
The latter could mean 41 mean solar days in a synodic month at that time
(from new moon to new moon).
The highest number in the stromatolite's mode could mean the same.
The mode's number 20 could be a sign of the high tide repeated twice
monthly. The mode's number 10 could mean that there has been two high tides
and two low tides in synodic month at that time. If it has been so, this
would mean that the solar tides had been larger at that time than they are
at present. The age determination is too inaccurate in this case and the
names of the samples are not all clear (Pannella 1972 a, BUL-6/BUL-7 or
UCLA-Bul-7 ).
WARRAWOONA STROMATOLITE, CALCULATED VALUES
The specimens are named in reference (Schopf 1983)
P.P.R.G 001-018,046,349,511-514,517,522,534-542
P.P.R.G = Precambrian Paleobiology Research Group.
(Schopf 1983 and error limit 32 million years, sample is partially melted).
TABLE 7
7. = experimental value, Highest count = (days/month) ?.
8. = experimental value,
Mode= (days/(month/4))-(days/(month/2))-(days/month) ?.
9. = experimental value, Tidal cycles per year = (months/year) ?.
1. 2. 3. 7. 8. 9.
------------------------------------------------------------------------
-3556 591,60 1009,77
------------------------------------------------------------------------
TABLE OF THE FOSSIL DATA ABOUT SOLAR DAYS PER SYNODIC MONTH
(Pannella 1972 a, Pannella 1972 b, Pannella MacClintock Thompson 1968,
Scrutton 1978 and Berry Barker 1975 a, see also: Pannella 1976):
PANNELLA'S FOSSIL DATA
TABLE 8
7. = experimental value, interpreted as (days/month), (Pannella 1972 a
and Pannella MacClintock Thompson 1968).
8. = standard deviation in experimental value (days/month)
9. = the code of the fossil specimen
10. = Highest count=(days/month)?, (Pannella 1972 a and Pannella 1972 b).
11. = Mode=(days/(month/4))-(days/(month/2))-(days/month) ?,
(Pannella 1972 a and Pannella 1972 b ).
12. = Tidal cycles per year = (months/year) ?,
(Pannella 1972 a and Pannella 1972 b ).
U = Upper, M = Middle, L = Lower.
YPM-IP = The collection of Division of Invertebrate Paleontology,
Peabody Museum, Yale University
Approximate absolute ages are estimated from Kulp (Kulp 1961).
(*) = in reference (Pannella 1972 a) and absolute age determination
method different than in reference (Pannella MacClintock Thompson 1968).
(**)= Pannella 1972 b.
(***)= The well preserved specimen from Belt Supergroup.
1. 2. 3. 7. 8. 9.
----------------------------------------------------------------------------
0 365,24 365,24 29,1 1,22 YPM-IP-26310
29,6 1,35 26307
29,0 0,87 26305
29,3 1,04 26312
29,2 1,05 26309
29,1 0,90 26304
29,4 1,45 28493 (*)
----------------------------------------------------------------------------
U- -10 366,12 366,11 29,7 1,05 YPM-IP-28494 (*)
29,4 0,97 26376 (*)
29,8 1,27 28495 (*)
----------------------------------------------------------------------------
M- -17 366,74 366,71 29,4 1,08 28483 (*)
----------------------------------------------------------------------------
-18 366,83 366,80 29,4 0,97 YPM-IP-26376
----------------------------------------------------------------------------
L- -27 367,62 367,58 29,2 0,99 28482 (*)
----------------------------------------------------------------------------
L- -35 368,32 368,27 29,6 0,97 26377 (*)
----------------------------------------------------------------------------
-40 368,76 368,71 29,6 0,97 YPM-IP-26377
----------------------------------------------------------------------------
M- -45 369,20 369,14 29,9 0,90 28496 (*)
----------------------------------------------------------------------------
-46 369,29 369,23 30,0 0,88 YPM-IP-26380
----------------------------------------------------------------------------
L- -50 369,64 369,58 29,4 1,03 28480 (*)
----------------------------------------------------------------------------
L- -54 369,99 369,93 29,6 1,55 28485 (*)
----------------------------------------------------------------------------
U- -58 370,34 370,27 30,0 0,88 26380 (*)
----------------------------------------------------------------------------
U- -70 371,39 371,33 29,7 1,03 26322 (*)
----------------------------------------------------------------------------
-72 371.57 371,50 29,7 1,03 YPM-IP-26322
29,9 1,16 26801
29,7 0,70 26802
30,2 1,03 26381
30,0 0,84 26382
----------------------------------------------------------------------------
U- -70 371,39 371,33 29,8 1,69 28497 (*)
29,6 0,80 11655 (*)
----------------------------------------------------------------------------
-205 383,17 383,36 29,8 1,24 YPM-IP-26803
29,8 1,15 26804
29,3 1,25 26805
----------------------------------------------------------------------------
M- -220 384,47 384,72 30,0 1,32 26803 (*)
29,4 1,18 26804 (*)
29,4 1,16 26805 (*)
----------------------------------------------------------------------------
-290 390,53 391,15 30,7 0,70 YPM-IP-26383
30,0 0,83 26378
29,9 0,52 26384
----------------------------------------------------------------------------
-305 391,83 392,54 30,2 1,20 YPM-IP-26323
----------------------------------------------------------------------------
L- -330 393,98 394,87 30,2 1,20 26323 (*)
----------------------------------------------------------------------------
-340 394,84 395,81 30,3 1,30 YPM-IP-26806
30,5 1,28 26807
----------------------------------------------------------------------------
M- -360 396,56 397,69 30,5 1,25 26808 (*)
30,2 1,56 28499 (*)
----------------------------------------------------------------------------
-380 398,28 399,58 30,5 1,25 YPM-IP-26808
U- -420 401,71 403,40 29,8 1,40 28505 (*)
----------------------------------------------------------------------------
L- -470 405,98 408,22 30,7 1,60 ? (*)
----------------------------------------------------------------------------
-510 409,38 412,13 31,6 3,15 YPM-IP-13849
----------------------------------------------------------------------------
MAINLY PANNELLA'S STROMATOLITE DATA:
TABLE 9
MAINLY PANNELLA'S STROMATOLITE DATA:
1. 2. 3. 10. 11. 12. 9.
----------------------------------------------------------------------------
-510 409,38 412,13 33 16-31 YPM-IP-13849
----------------------------------------------------------------------------
-510(**) 409,38 412,13 13 YPM-IP-13849
13 28473
----------------------------------------------------------------------------
-950(***)446,02 458,19 31 16-31 YPM-IP-28459
----------------------------------------------------------------------------
-900- 441,94- 452,65-
473,94 499,64
-1300(**) 13 YPM-IP-28459
13 28471/2
----------------------------------------------------------------------------
-1750 507,73 561,10 39 18-36 YPM-IP-28510
28511
----------------------------------------------------------------------------
-1800- 511,31- 568,62-
518,34 584,13
-1900(**) 13 YPM-IP-28465
YPM-IP-28513
38 ? (Biwabik, Mohr 1975)
----------------------------------------------------------------------------
-1845- 514,50- 575,52-
548,81 667,16
-2370(**) 13 YPM-IP-28469
13 28468
? (Great Slave,GSM 77325,Jones,1981)
----------------------------------------------------------------------------
<-2500 556,33 693,70 YPM-IP-28467
(**)
----------------------------------------------------------------------------
<-2800 571,69 762,65 41 10-20-40 BUL-6/BUL-7 ? or UCLA-BUL-7
----------------------------------------------------------------------------
Biwabik stromatolite's spectrum (Mohr 1975):
(12-13)-18-(24-26)-32-44-48 (Mohr's counting method) and
--
(12-13)-18-(24-26)-32-38-44 (Pannella's counting method), ( ) = between.
-----
THE BIVALVE FOSSIL DATA OF BERRY AND BARKER:
TABLE 10
4
1. = T / 10 (centuries), (Kulp 1961, ( )=Berry Baker 1975 a, Fig 2, p. 21)
7. = experimental value, interpreted as (days/month),(Berry Barker 1975 a)
9. = the name of the bivalve fossil specimen, era and formation.
1. 2. 3. 7. 9.
----------------------------------------------------------------------------
0- 365,24- 365,24- PLEISTOCENE
-1 365,33 365,33 29,5 Chione californiensis (Sandstone near Punta
Cholla, Sonora, Mexico)
29,5 Chione succincta (Palos Verdes Formation,
Newport Beach, California)
29,6 Chione undatella (San Pedro Sandstone, San
Pedro, California)
----------------------------------------------------------------------------
-1- 365,33- 365,33- PLIOCENE
-13 366,39 366,36
(-10) 29,6 Chione cancellata (Caloosahatchee Formation,
Southern Florida)
29,7 Codakia orbicularis (Caloosahatchee Formation,
Southern Florida)
----------------------------------------------------------------------------
-25- 367,44- 367,40- OLIGOCENE
-36 368,41 368,36
(-40) 29,6 Crassatella lincolnensis (Sacate-Gaviota
Formation, Santa Inez, California)
29,5 Macrocallista hornii (Sacate-Gaviota
Formation, Santa Inez, California)
----------------------------------------------------------------------------
-36- 368,41- 368,36- ECOCENE
-58 370,34 370,28
(-45) 29,7 Meretrix splendida (Lutetian, Morigny, France)
----------------------------------------------------------------------------
-58- 370,34- 370,28- PALEOCENE
-65 370,95 370,89
(-50) 29,7 Venerid (Venerid shell fragments in thin
sections of Meganos Sandstone, Byron
Quadrangle, California)
----------------------------------------------------------------------------
-65- 370,95- 370,89- CRETACEOUS
-135 377,07 377,07
(-100) 29,7 Crassatella vadosus (Ripley Formation, Coon
Creek, Tennessee)
29,6 Idonearca vulgaris (Ripley Formation, Coon
Creek, Tennessee)
29,8 Glycymeris lacertosa (Ripley Formation, Coon
Creek, Tennessee)
29,8 Lucina subundata (Cody Shale,Greybull,Wyoming)
----------------------------------------------------------------------------
-135- 377,07- 377,07- JURASSIC
-180 381,00 381,10
(-160) 29,8 Lima gigantea (Leamington, England)
----------------------------------------------------------------------------
-180- 381,00- 381,10 TRIASSIC
-230 385,34 385,63
(-220) 29,8 Septocardia sp. (Luning Formation, Pilot
Mountains, Nevada)
----------------------------------------------------------------------------
-280- 389,67- 390,22- CARBONIFEROUS
-345 395,27 396,28
(-310) 30,0 Astartella concentrica (Gramham Formation,
Texas)
30,2 Myalina subquadrata (Wayland Formation,
Brownwood, Texas)
30,2 Conocardium sp. (Carboniferous, Belgium)
----------------------------------------------------------------------------
-345- 395,27- 396,28- DEVONIAN
-405 400,42 401,96
(-350) 30,5 Conocardium sp. (Alpena Limestone, Michigan)
----------------------------------------------------------------------------
SCRUTTON'S MIDDLE DEVONIAN CORAL FOSSIL DATA:
TABLE 11
7. = experimental values and average, interpreted as (days/month),
(Scrutton 1964 and Scrutton 1970)
8. = experimental average, months/year
9. = the code of the fossil specimen and the era.
10. = Number of consecutive bands.
11. = Ridges per band 27 28 29 30 31 32 33 34 35
1. 2. 3. 7. 8. 9.
----------------------------------------------------------------------------
-365- 397,00- 398,16- Middle Devonian
-390 399,14 400,53
11.
10. 27 28 29 30 31 32 33 34 35
----------------------------------------------------------------------------
5 1 2 1 1 30,4
4 1 1 1 1 31,5
3 1 1 1 31,0
----
30,9 12,91 BM R44851
----------------------------------------------------------------------------
13 1 2 3 1 4 2 30,85 12,93 OUM DT2
----------------------------------------------------------------------------
8 1 3 2 2 30,9
2 2 30,0
----
30,7 12,99 OUM DT3
----------------------------------------------------------------------------
16 1 1 8 4 2 30,7 12,99 OUM DT4
----------------------------------------------------------------------------
7 1 1 1 2 2 30,15
5 2 2 1 30,8
----
30,4 13,12 OUM DT5
----------------------------------------------------------------------------
7 4 1 2 30,7
5 2 1 2 31,0
2 1 1 31,0
----
30,8 12,95 OUM DT6
----------------------------------------------------------------------------
12 2 4 2 1 2 1 31,0 12,87 OUM DT7
----------------------------------------------------------------------------
7 1 1 4 1 30,6 13,04 OUM DT8
----------------------------------------------------------------------------
9 3 4 1 1 30,0 13,3 OUM DZ32
----------------------------------------------------------------------------
8 2 1 2 2 1 29,9 13,34 OUM DZ33
----------------------------------------------------------------------------
Silurian
BM R21668
----------------------------------------------------------------------------
Cretaceous
BM R41812
----------------------------------------------------------------------------
In the very well preserved specimen OUM DT2, the interval betveen the top
edges of the two swells is 401 ridges (days/year). This unit comprises
thirteen bands (months/year), each on average with 30,85 ridges
(days/month). Scrutton has achieved values for months/year by dividing 399
(days/year) with corresponding value days/month. The interpretation of
ridges is my own.
OUM = Oxford University Museum. BM = British Museum (Natural History).
THE SEDIMENT SAMPLE OF WILLIAMS:
From the time about 650 million years ago Williams has investigated
sediment layers and acieved result that there has been about 13,1 synodic
months in tropical year at that time (error limit 0,5 days/month was given,
the error limit from the age determination was not given but it is probably
about 50 million years) (Williams 1989).
TABLE 12
7. = experimental value (months/year), (Williams 1989)
8. = error limit for 7. (months/year)
9. = experimental value (days/month), (Williams 1989)
10. = error limit for 9. (days/month)
11. = experimental value (days/year), (Williams 1989)
12. = error limit for 11. (days/year)
1. 2. 3. 7. 8. 9. 10. 11. 12.
----------------------------------------------------------------------------
-650 421,20 426,15 13,1 0,5 30,5 1,5 400 20
----------------------------------------------------------------------------
IMAGINED SITUATION OF THE AREAS EXTERNAL TO THE DEFINED AREA
-4,55 billion years < T < -4,5 billion years and
-4,5 billion years < T < -4,4 billion years and
-4,4 billion years < T < -3,8 billion years.
Earth was supposedly created approximately 4.55 billion years ago as
condensating from carbonaceous chondrite meteorites (The Cambridge
Encyclopedia of Earth Sciences 1982). Before 4,55 billion years ago the
"length of a day" may have been very large. The very large value of the
denominator corresponds approximately to the non-rotating galactic "dust
cloud". The "tropical year" could have had a value prior to the
denominator's large value, if the creation of the Sun had occured before
Earth's creation. This would correspond to the rotation of the galactic
"dust cloud" around the recently created Sun (compare for example: Lada
and Shu 1990). Before the first area, the number of days in a year would
have been nearly zero. On the first area, the denominator would have
decreased from the very large value to 5 - 7 of our present hours at
approximately 4,5 billion years ago. (Schopf 1983, Pages 260-263). On the
second area the denominator would have decreased further to a minimum at a
point 4.4 billion years ago, which is due to the formation of Earth's iron
core (Wilhelms McCauley Trask 1987). This point of time is very inaccurate,
because it is roughly located in the time period 4.5 to 4 billion years ago
At that time, the length of a day on Earth would have been at least four of
our present hours, due to the holding together of the globe. The length of
a day may have been about 12 - 15 present hours approximately 4,0 billion
years ago according to the reference (Schopf 1983).
The probable compression or capture or fission of the Moon has also
apparently happened 4.55 - 4,4 billion years ago. The Moon's crust is a
little thinner on the Moon's visible face than on the hidden face, which
explains the relative rarity of volcanism on the latter. This asymmetry in
the mass distribution (an excess of crust on the hidden face) can be
related to the synchronism of the rotation and revolution of our satellite
(The Cambridge Atlas of Astronomy 1985, Pages 82-117).
The radius of the Moon towards the Earth is about four kilometers greater
than it is in directions at right angles. This is in fact much greater than
any tidal effect and the Moon's elongated shape must have been formed when
Moon was younger and hotter, and the shape of the Moon has been frozen when
it cooled and formed its extensive lithosphere. The effects of tides in the
solid body of the Moon slowed down its rotation until it locked into
syncronism with its orbital motion. Today there is no net torque on the
Moon but were it to spin up or spin down, the torque on its elongated shape
would in each case act to return the rotation to synchronism; the situation
is stable (The Cambridge Encyclopaedia of Astronomy 1977).
For a long time astronomers have noted that all the Moon's topographical
features are statistically oriented in three dominant directions:
north-south, north-east-south-west and north-west-south-east. This
arrangement which has been called the 'lunar grid' is the reflection of
former disclocations caused by the slowing down of the Moon's rotation
under the effects of the tides.
The whole surface of the Moon is affected everywhere by faults and
stress-induced rilles, certifying to a tendency of the Moon's surface to be
under stress at the very moment when the volcanism of the seas was in full
development. These rilles are in the main directed radially or tangentially
to the Imbrium basin (old crater), whose presence seems to have 'oriented'
the Moon's expansion. (The Cambridge Atlas of Astronomy 1985, Pages 82-117).
After 3,8 billion years, the coefficients of the time formula can have
slight undulation in the places where the distance from the Earth to the
Moon has a minimum or maximum, if there exists any minimums or maximums in
Earth-Moon distance in ancient times.
CRITICAL EXAMINATION OF TIME FORMULA
There is some inaccuracy in the determination of the age of fossils,
there values are typically in steps of 10 million years. In determination of
the age of the oldest fossils the relative error can be large. Time limits
of the geological time scale have changed from the geological time scale
which Kulp drafted in 1961 (Kulp 1961) and many points are still uncertain.
In the future the test points from the oldest fossils will hopefully give
answer to the question: how the coefficient of T in the denominator of the
time formula depends on T. Well preserved stromatolites whose ages can be
determined accurately could have conclusive meaning in solving this problem.
It is also possible that any sharp distinction between the numerator and
the denominator of the time formulae cannot be made. Ages of the fossil
specimens should be determined at least to an accuracy of 10 million years
and experimental fossil points should be more complete in order to make more
accurate month formula for approximating of the C(T). The poor accuracy of
the age determination of the well preserved Bulawayan stromatolite as well
as in case of other stromatolites is problematic.
At present solar tides are so small that they cannot cause significant
decrease in distance between the Earth and the Sun. Bulawayan stromatolite
could indicate that solar tides were larger in past than at present.
In addition there is missing experimental data concerning about the rotation
of the Sun on the geologic time scale. One possibility is that just when the
Sun condenceded from interstellar gas it must have rotated much faster than
the present one, so the rotation rate of the Sun has possibly slowed down on
the geologic time scale from its maximum value (about 3 present hours,
Runcorn 1967) to the present value (about 27 solar days). It remains partly
open how fast this slowing has happened and what role an expanding solar
corona had when interacting with the strong solar wind to this slowing. There
are several models of the formation of sunlike stars (see for example: Lada
and Shu 1990, Schatzman 1960).
The Sun does not rotate rigidly like Earth; this is because the Sun is
gaseous throughout. The polar regions of the photosphere take 37 days to
rotate once with respect to the distant stars, whereas the equator takes
26 days. As observed from Earth, which is moving around the Sun, the
corresponding synodic periods are 41 and 27 days. It is possible that the
non-rigid rotation of our Sun is caused by rapid rotation of the solar
interior, which would lead to a shear stress, and swifter rotation, at the
equator of the visible surface (The Encyclopaedia of Astronomy 1977).
The assumption that Sun's mass has remained constant along the whole
geologic time scale is not consistent at all time points with the point of
view that at the creation phase and at so called T-Tauri phase changes of
the Sun's mass could have been be significant (Runcorn 1967, Lada and Shu
1990).
Some chaotic oscillation possibly exists in internal prosesses of the
Earth on the geologic time scale which may have significant influence on
Earth's rotation (see for example: Powell 1991). And the geology of a Earth
size planet without a Moon seems to be quite different than Earth's geology
(see for example: Reports of Venus Geology 1991).
Lastly there remains to be investigated in future somewhat open question
of tidal density wave interactions, caused by our spiral galaxy Milky Way or
by around Milky Way rotating Large and Small Magellanic Cloud galaxies, with
the Sun, with our Planetary System and with the Earth-Moon system.
Distances of these two neigbour galaxies from the Milky Way is possible
oscillatory in nature and main trend is decreasing on the geologic time scale.
It has been estimated that these distances have decreased about 50 percent
in 10 billion years. Decreasing rotation period of these neigbour galaxies is
about 500 million years at present (see for example: Dekker 1976, Yuan and
Cheng 1989, 1991, The Cambridge Atlas of Astronomy 1985, Binney Tremaine 1987).
REFERENCES CITED:
1. Allen, C.W., 1973.
Astrophysical Quantities.
3 edition, University of London, The Athlone Press.
2. Berry, W. B. N., Barker, R. M., 1975 a.
Growth Increments in Fossil and Modern Bivalves.
In:
Rosenberg, G. D., Runcorn, S. K. (Editors), 1975.
Growth Rhythms and the History of the Earth's Rotation.
Willey Interscience, New York, Pages 9-24.
3. Binney, J. and Tremaine, S, 1987.
Galactic Dynamics.
Princeton University Press, Princeton, New Jersey,
Pages 17 and 428-431.
4. The Cambridge Atlas of Astronomy, 1985.
Cambridge University Press and Newnes Books.
Printed in France 1985.
5. The Cambridge Encyclopaedia of Astronomy, 1977.
Jonathan Cape thirty Bedford Square London.
6. The Cambridge Encyclopaedia of Earth Sciences, 1982.
Cambridge University Press.
7. Dekker, E., 1976.
Spiral structure and the dynamics of galaxies.
Physics Reports (Section C of Physics Letters), Volume 24,
Number 5, April 1976, North-Holland Publishing Company, Pages 315-389.
8. Eicher, D. L., 1976.
Geologic Time.
2nd edition, Prentice / Hall International, Inc., London 1976, Figure
on page 117.
9. Halberg, F. and Conner, R. L., 1961.
Proc. Minn. Acad. Sci., Volume 29, Pages 227-239.
10. Jones, C. B., 1981.
Periodicities in stromatolite lamination from Early Proterozoic
Hearne Formation, Great Slave Lake, Canada.
Palaeontology, Volume 24, Part 2, Pages 231-250.
11. Kulp, J. L., 1961.
Geologic Time Scale.
Science, N.Y., Volume 133, pages 1105-1114.
12. Lada, C. J. and Shu, F. H., 1990.
The Formation of Sunlike Stars.
Science, Volume 248, Number4, Pages 564-572, May 1990.
13. Mohr, R. E., 1975.
Measured periodicities of the Biwabik (Precambrian) stromatolites
and their geophysical significance.
In:
Rosenberg, G. D. and Runcorn, S. K. (Editors), 1975.
Growth Rhythms and The History of the Earth's Rotation.
Wiley Interscience, New York, Pages 43-55.
14. Munk, W. H., and MacDonald, G. L. F., 1960.
The Rotation of the Earth.
Cambridge University Press, London, Page 250, 323 pages.
15. Pannella, G., MacClintock, C. and Thompson, M., 1968.
Paleontological evidence of variation in length of synodic month
since Late Cambrian.
Science, Volume 162, Pages 792-796. Washington, D.C.
16. Pannella, G., 1972 a.
Paleontological Evidence on the Earth's Rotational History
Since the Early Precambrian.
Astrophys. Space Science, Volume 16, Pages 212-237.
17. Pannella, G., 1972 b.
Precambrian stromatolites as paleontological clocks.
Twenty-Fourth International Geological Congress, Section 1, Pages 50-57.
18. Pannella, G., 1976.
Tidal Growth Patterns in Recent and Fossil Mollusc Bivalve Shells:
a Tool for the Reconstruction of Paleotides.
Naturwissenschaften, Volume 63, Pages 539-543.
19. Powell, C. S., 1991.
Trends in geophysics: Peering Inward.
Scientific American, Pages 72-81, June 1991.
20. Reports of Venus Geology, 1991.
(Geology of Earth size planet without a Moon).
Science, Volume 252, Pages 247-312.
21. Rosenberg, G. D., Runcorn, S. K. (Editors), 1975.
Growth Rhythms and the History of the Earth's Rotation.
Willey Interscience, New York, 559 pages.
22. Runcorn, S. K. (Editor), 1967.
International Dictionary of Geophysics.
-Absolute Time Data From Palaeontology, Pages 1-2, Volume 1.
-Sun, Origin of, Pages 1484-1487, Volume 2.
Pergamon Press Ltd., London, Volumes 1 and 2.
24. Schatzman, E., 1960.
Special Tech. Rept. Number 3, Mt. Wilson and Palomar Obs.
25. Schopf, J. William, (Editor), 1983.
Earth's Earliest Biosphere. Its Origin and Evolution.
Princeton University Press, Princeton, New Jersey.
26. Scrutton, C. T., ( 1964 ) 1965.
Periodicity in Devonian Coral Growth.
Palaeontology, Volume 7, Part 4, Pages 552-558, Plates 86-87.
27. Scrutton, C. T., 1970.
Evidence for a monthly periodicity in the growth of some corals.
In:
Runcorn, S. K. (Editor), 1970.
Paleogeophysics.
Academic Press, London, Pages 11-16.
28. Scrutton, C. T., 1978.
Periodic Growth Features in Fossil Organisms and the Length of the Day
and Month.
In:
Brosche, P. and Sundermann, J. (Editors), 1978.
Tidal Friction and the Earth's Rotation.
Springer-Verlag, New York. 241 pages, Pages 154-196.
29. Vanyo, J. P. and Awramik, S. M., 1985.
Stromatolites and Earth-Sun-Moon Dynamics.
Precambrian Research, volume 29, page 121.
30. Wells, J. W., 1963.
Coral Growth and Geochronometry.
Nature, London, Volume 197, pages 948-950.
31. Wells, J. W., 1970.
Problems of Annual and Daily Growth-rings in Corals.
In:
Runcorn, S. K. (Editor), 1970.
Paleogeophysics.
Academic Press, London, Pages 3-9.
32. Wilhelms, D. E., McCauley, J. F., Trask, N. J., 1987.
The Geologic History of the Moon.
United States Goverment Printing Office, Washington.
33. Williams, G. E., 1989.
Precambrian Tidal Sedimentary Cycles and Earth's Paleorotation.
EOS, volume 70, number 3, pages 40-41.
34. Yuan, C. and Cheng, Y., 1989.
Resonance excitation of spiral density waves in a gaseous disk.
1. A. Linear theory.
Astrophysical Journal, volume 340, Page 216-240, (Paper 1).
35. Yuan, C. and Cheng, Y., 1991.
Resonance excitation of spiral density waves in a gaseous disk.
2. A. Nonlinear theory and application to the 3 kiloparsec arm.
Astrophysical Journal, volume 376, Pages 104-114, (Paper 2).
I would like to acknowledge Neil Jackson for his help in translating
the text. I took this task to myself as a calendar maker's question.
(See: sci.astro, number= 5431, name= New Calendar)
I have sent earlier version of this work also 27.11.1991 to the Geology
magazine (Geological Society of America, 3300 Penrose Place, P.O. Box 9140,
Boulder, Co 80301, U.S.A).
I sent this work is also 10.12.1991 to sci.astro (number= 5394, name=
Ancient Time Formula) for criticism.
I would be grateful of suggestions and criticism of C(T)'s and P(T)'s
formulas and their possible connections.
Kiiminki 16.12.1991
Hannu Poropudas

Question: how many days in a year was 410 million years ago

400 நாட்களும்

In fact, (410 million years ago) a year was 400 days, a day was 21.8 hours.

how many days in a year was 410 million years ago

Question: how long was a day in 400 million years ago

21.8 மணிநேரமுமாக

how long was a day in 400 million years ago

Question: how many days are there in a year

Question: how many μs are there in the day of the earths earth's earth's

how many μs are there in the day of the earths earth's earth's

Question: how many times a year does the moon change in the earth's earth's day

23 µs வீதம் பூமியின் ஒரு நாள் நீள்வதும்

how many times a year does the moon change in the earth's earth's day

Question: when was 400 days ago

410 மில்லியன் ஆண்டுகளுக்கு முன்

In fact , ( 410 million years ago ) a year was 400 days , a day was 21.8 hours .

இந்தப் பேரலைகள் ஊடாடுவதன் காரணமாக, சந்திரன் பூமியை விட்டு வருடத்திற்கு 38 மி.மீ. விலகிச் செல்கிறது. பல மில்லியன் வருடங்களுக்கு மேலாக, இந்த சிறு மாற்றங்களும்-ஒரு வருடத்திற்கு 23 µs வீதம் பூமியின் ஒரு நாள் நீள்வதும், பல குறிப்பிடத்தகுந்த மாற்றங்களை ஏற்படுத்தியுள்ளன. எடுத்துக்காட்டாக, தேவோனியன் காலத்தின் பொழுது, (தோராயமாக 410 மில்லியன் ஆண்டுகளுக்கு முன்) ஒரு வருடத்திற்கு 400 நாட்களும், ஒரு நாளுக்கு 21.8 மணிநேரமுமாக இருந்தது.

பொழுது, (தோராயமாக 410 மில்லியன் ஆண்டுகளுக்கு முன்) ஒரு வருடத்திற்கு 400 நாட்களும், ஒரு நாளுக்கு 21.8 மணிநேரமுமாக இருந்தது.

Due to the extinction of these spots, the moon runs 38 mm per year away from the Earth. For more than a few million years, these small changes have caused a number of significant changes, including a year-on-year 23 μs in the day of the Earth's Earth's Earth's Earth's Earth. In fact, (410 million years ago) a year was 400 days, a day was 21.8 hours.

In fact, (410 million years ago) a year was 400 days, a day was 21.8 hours.

But this is a transitional thought, and the earth as well as the rain and the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well.

A long-term numerical solution for the insolation quantities of the Earth
Abstract
We present here a new solution for the astronomical computation of the insolation quantities on Earth spanning from -250 Myr to 250 Myr. This solution has been improved with respect to La93 (Laskar et al. \cite{Laskar1993}) by using a direct integration of the gravitational equations for the orbital motion, and by improving the dissipative contributions, in particular in the evolution of the Earth-Moon System. The orbital solution has been used for the calibration of the Neogene period (Lourens et al. \cite{Lourens2004}), and is expected to be used for age calibrations of paleoclimatic data over 40 to 50 Myr, eventually over the full Palaeogene period (65 Myr) with caution. Beyond this time span, the chaotic evolution of the orbits prevents a precise determination of the Earth's motion. However, the most regular components of the orbital solution could still be used over a much longer time span, which is why we provide here the solution over 250 Myr. Over this time interval, the most striking feature of the obliquity solution, apart from a secular global increase due to tidal dissipation, is a strong decrease of about 0.38 degree in the next few millions of years, due to the crossing of the s6+g5-g6 resonance (Laskar et al. \cite{Laskar1993}). For the calibration of the Mesozoic time scale (about 65 to 250 Myr), we propose to use the term of largest amplitude in the eccentricity, related to g2-g5, with a fixed frequency of 3.200''/yr, corresponding to a period of 405 000 yr. The uncertainty of this time scale over 100 Myr should be about 0.1%, and 0.2% over the full Mesozoic era.
- Publication:
- Astronomy and Astrophysics
- Pub Date:
- December 2004
- DOI:
- 10.1051/0004-6361:20041335
- Bibcode:
- 2004A&A...428..261L
- Keywords:
- chaos;
- celestial mechanics;
- ephemerides;
- Earth

பூமியின் சுழலும் அச்சு நீள்வட்டப்பாதையை அடைய நேர்ந்தால் உயர்ந்தபட்ச காலநிலை மாறுபாடுகளினால் உயர்ந்தபட்ச மோசமான தட்பவெப்ப நிலையை எதிர்கொள்ள வேண்டியிருக்கும். ஒரு துருவம் கோடைக்காலத்தில் சூரியனை நோக்கியும் குளிர்காலத்தில் சூரியனுக்கு எதிர் திசையிலும் அமைந்திருக்கும். இதனை ஆராய்ந்த வான் கோள் அறிவியலாளர்கள் இது எல்லா பெரிய விலங்குகளையும் மற்றும் உயர்ந்த தாவரங்களையும் அழிக்கக்கூடும் என கருதுகின்றனர். எனினும் இது ஒரு சர்ச்சைக்குரிய கருத்தாகும், மேலும் பூமியைப் போலவே சுழற்சியையும் சுழலும் காலத்தையும் உடைய ஆனால் பெரிய சந்திரனும் திரவ உட்கருவும் இல்லாத செவ்வாய் கோளை பற்றிய ஆராய்ச்சி இதற்கு ஒரு தீர்வைக் கொடுக்கலாம்.

பூமியின் சுழலும் அச்சு நீள்வட்டப்பாதையை அடைய நேர்ந்தால் உயர்ந்தபட்ச காலநிலை மாறுபாடுகளினால் உயர்ந்தபட்ச மோசமான தட்பவெப்ப நிலையை எதிர்கொள்ள வேண்டியிருக்கும். ஒரு துருவம் கோடைக்காலத்தில் சூரியனை நோக்கியும் குளிர்காலத்தில் சூரியனுக்கு எதிர் திசையிலும் அமைந்திருக்கும். இதனை ஆராய்ந்த வான் கோள் அறிவியலாளர்கள் இது எல்லா பெரிய விலங்குகளையும் மற்றும் உயர்ந்த தாவரங்களையும் அழிக்கக்கூடும் என கருதுகின்றனர்.

எனினும் இது ஒரு சர்ச்சைக்குரிய கருத்தாகும், மேலும் பூமியைப் போலவே சுழற்சியையும் சுழலும் காலத்தையும் உடைய ஆனால் பெரிய சந்திரனும் திரவ உட்கருவும் இல்லாத செவ்வாய் கோளை பற்றிய ஆராய்ச்சி இதற்கு ஒரு தீர்வைக் கொடுக்கலாம்.

Thus, when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth, the earth is in the midst of the earth. But this is a transitional thought, and the earth as well as the rain and the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well.

But this is a transitional thought, and the earth as well as the rain and the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well as the sun as well.

Astrophysics
Title:The role of chaotic resonances in the solar systemDownload PDF
Abstract: Our understanding of the Solar System has been revolutionized over the past decade by the finding that the orbits of the planets are inherently chaotic. In extreme cases, chaotic motions can change the relative positions of the planets around stars, and even eject a planet from a system. Moreover, the spin axis of a planet-Earth's spin axis regulates our seasons-may evolve chaotically, with adverse effects on the climates of otherwise biologically interesting planets. Some of the recently discovered extrasolar planetary systems contain multiple planets, and it is likely that some of these are chaotic as well.
Submission historyFrom: Matthew J. Holman [view email]
[v1] Fri, 30 Nov 2001 17:36:07 UTC (150 KB)
[v2] Sun, 2 Dec 2001 03:32:03 UTC (150 KB)
Full-text links:
Download:
References & Citations
Bibliographic and Citation Tools
Bibliographic Explorer (What is the Explorer?)
Litmaps (What is Litmaps?)
scite Smart Citations (What are Smart Citations?)
Code and Data Associated with this Article
Demos
Recommenders and Search Tools
Connected Papers (What is Connected Papers?)
CORE Recommender (What is CORE?)
IArxiv Recommender (What is IArxiv?)
arXivLabs: experimental projects with community collaborators
arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.
Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them.
Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs and how to get involved.

Through changing the condition of the earth, the moon increasingly affects the advance of life on the earth. The results of the telescopic research and the patterns of the calculator show us that the condition of the earth is in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon.

Habitable Planets with High Obliquities
Abstract
The obliquities of the terrestrial planets have been shown to vary chaotically and by large amounts in times less than 10 Myr, thus inviting the possibility for Earth to occasionally reach high obliquity where it might experience climatic conditions unfavorable for life. Although Earth escapes this fate by having its rotation axis stabilized by the Moon, many extrasolar Earth-like planets without large satellites should be subjected to periods of high obliquity. The number of worlds supporting life outside the Solar System, then, may be far fewer than has been suggested if high obliquities render moon-less Earths uninhabitable. Climates at high obliquity are particularly harsh on middle and high latitude continents that warm and cool rapidly in response to large insolation swings. These areas exhibit a wide range of temperatures over a seasonal cycle, with extremes reaching well above or below 273 Kelvin, making them seasonally unsuitable for water-dependent life. We demonstrate here that Earth-like planets will have their temperature extremes mitigated at high obliquity if they possess dense CO2 atmospheres, as is likely for many planets situated in the outer habitable zone (HZ) of a Sun-like star. The climate stabilizing mechanism governing atmospheric CO2 on Earth-like planets is carbonate-silicate weathering. Planets with atmospheres rich in CO2 demonstrate small latitudinal temperature gradients and seasonal temperature cycles, and thus remain habitable at high obliquities.
- Publication:
- Lunar and Planetary Science Conference
- Pub Date:
- March 1996
- Bibcode:
- 1996LPI....27.1437W
- Keywords:
- ATMOSPHERES;
- CLIMATE;
- EXOBIOLOGY;
- OBLIQUITY;
- ZONES: HABITABLE

பூமியின் தட்பவெப்பநிலையை மாற்றுவதன் மூலம் சந்திரன் பூமியில் வாழ்க்கையின் முன்னேற்றத்தை பெரிதும் பாதித்திருக்கிறது. தொல்லுயிர் ஆராய்ச்சியின் முடிவுகளும் மற்றும் கணினியின் மாதிரிகளும் பேரலைகளுக்கு சந்திரனுடன் உள்ள கவர்ச்சியினால்தான் பூமியினுடைய அச்சின் சாய்வு நிலையாக உள்ளது என்பதை நமக்கு காட்டுகிறது. சூரியனும் இதர கோள்களும் பூமியின் நிலநடுக்கோட்டைச் சார்ந்த வீக்கத்திற்கு கொடுக்கும் உந்து அழுத்தத்திற்கு எதிராக இந்த நிலைப்புத்தன்மை இல்லையெனில் பூமியின் சுழலும் அச்சு ஒரு நிலையிலன்றி குழப்பமானதாக இருந்திருக்கும், மேலும் செவ்வாய் கோளில் நடப்பதைப் போல மில்லியன் வருடங்களுக்கு மேல் நிலைமாறான மாற்றங்களை ஏற்படுத்தியிருக்கும் என சில கொள்கையாளர்கள் நம்புகிறார்கள்.

Through changing the condition of the earth, the moon increasingly affects the advance of life on the earth. The results of the telescopic research and the patterns of the calculator show us that the condition of the earth is in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon. Thus, when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth; when the earth is in the midst of the earth, the earth is in the midst of the earth, the earth is in the midst of the earth.

Through changing the condition of the earth, the moon increasingly affects the advance of life on the earth. The results of the telescopic research and the patterns of the calculator show us that the condition of the earth is in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon in the condition of the moon.

The earth is less than two sub-sweets, 3753 square meters and 2002 AA29.

|You are in: Science/Nature|
|
Monday, 21 October, 2002, 16:27 GMT 17:27 UK
|
Earth's little brother found
Asteroid 2002 AA29 is only about 100 metres wide and never comes closer than 5.8 million kilometres (3.6 million miles) to our planet.
But it shares the Earth's orbit around the Sun, at first on one side of the Earth and then escaping to travel along our planet's path around the Sun until it encounters the Earth from the other side.
Then it goes back again.
Researchers are speculating that 2002 AA29 could be visited by astronauts or used to understand the threat to our planet posed by such rocks from space.
Co-orbital object
2002 AA29 was discovered by the linear automated sky survey project on 9 January 2002.
Martin Connors of Athabaseca University in Canada writes in the journal Meteoritics and Planetary Science that it "moves in a very Earth-like orbit," and is the "first true co-orbital object of Earth."
According to Helena Morais of the University of Lisbon and Allesandro Morbidelli of the University of Nice, writing in a paper to be published in the journal, Icarus: "2002 AA29 seems to be in a temporary horseshoe-like orbit with the Earth."
This puts 2002 AA29 is in the same class as 3753 Cruithne, a similar rocky body in a horseshoe orbit around the Earth.
But astronomers classify 2002 AA29 as the first real co-orbital body found associated with the Earth because it more completely shares the Earth's path around the Sun.
Co-orbiting asteroids have been found around other planets.
Eight such objects have been found associated with Mars. But despite detailed searches no one has yet found any Trojan objects near the Earth.
It is clear that 2002 AA29 was discovered by accident at a time when it was at one end of its horseshoe orbit and, being at its closest to the Earth, was bright enough to be detected in an automated sky survey.
Detailed observations of its trajectory through space show that 2002 AA29 will reach its minimum close approach to the Earth - 12 times the distance between Earth and the Moon - at 1900 GMT on 8 January 2003.
Cat-and-mouse game
Thereafter it will travel ahead of the Earth moving faster than our planet does, until after 95 years it will catch up with the other side of the Earth and then reverse its motion.
Analysis of 2002 AA29's motions have revealed a remarkable event that happens to it every few thousand years.
In AD 550, and again in AD 2600 and AD 3880, the rock become, for a while, a true satellite of our planet, in effect Earth's second moon, although technically it will remain under the gravitational control of the Sun.
It remains a second moon to Earth for about 50 years until it escapes.
Although only about 100 metres across, 2002 AA29 may play a role in the manned exploration of space out of all proportion to its size.
Already researchers are speculating that it could be visited by an unmanned spaceprobe or even become the first object after the Moon to be stepped on by astronauts.
The object could tell us a lot about the composition of asteroids.
Some have speculated that it could be nudged into a permanent Earth orbit where it could be studied at greater length.
See also:
11 Sep 02 | Science/Nature
12 Sep 02 | Science/Nature
Internet links:
The BBC is not responsible for the content of external internet sites
Top Science/Nature stories now:
Links to more Science/Nature stories are at the foot of the page.
|E-mail this story to a friend|
Links to more Science/Nature stories
To BBC Sport>> | To BBC Weather>> | To BBC World Service>>
----------------------------------------------------------------------------------
© MMIII | News Sources | Privacy

Question: how many sub-sweets does the earth have

The earth is less than two sub-sweets, 3753 square meters and 2002 AA29.

Question: how many square meters is earth in square meters

how many square meters is earth in square meters

Question: how many square meters is the earth

3753 க்ருதினே

Question: is the earth more or less than two sub-sweets

is the earth more or less than two sub-sweets

Question: when did the earth become less than two square meters

when did the earth become less than two square meters

The earth is less than two sub - sweets , 3753 square meters and 2002 AA29 .

பூமிக்கு குறைந்தது இரண்டு துணை-சுற்று பெரு விண்கற்கள், 3753 க்ருதினே மற்றும் 2002 AA29 என இருக்கிறது.

பூமிக்கு குறைந்தது இரண்டு துணை-சுற்று பெரு விண்கற்கள், 3753 க்ருதினே மற்றும் 2002 AA29 என இருக்கிறது.

The earth is less than two sub-sweets, 3753 square meters and 2002 AA29.

The earth is less than two sub-sweets, 3753 square meters and 2002 AA29.

In the light of the living is a cage, and if the living keeps the living, the living will appear there, and it is believed to be the living.

The earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth.

புவியில் உயிர்களின் புழக்கம் ஒரு கோள், உயிர்களை தக்க வைத்துக் கொள்ளுமானால் உயிர்கள் அங்கே தோன்றாவிடினும் அது உயிர்கள் புழங்கத்தக்கதாக கருதப்படுகிறது. பூமி (தற்போதைய கூற்றுகளின் படி) உயிர்கள் வாழ்வதற்கு வேண்டிய திரவ நீர், சுற்றுச் சூழலில் கடினமான உயிர் வேதியல் மூலக்கூறுகள் உருவாகும் தன்மை மற்றும் வளர்ச்சிதை மாற்றத்திற்கு தேவையான சக்தி ஆகியவற்றைப் பெற்றிருக்கிறது.

புவியில் உயிர்களின் புழக்கம் ஒரு கோள், உயிர்களை தக்க வைத்துக் கொள்ளுமானால் உயிர்கள் அங்கே தோன்றாவிடினும் அது உயிர்கள் புழங்கத்தக்கதாக கருதப்படுகிறது.

பூமி (தற்போதைய கூற்றுகளின் படி) உயிர்கள் வாழ்வதற்கு வேண்டிய திரவ நீர், சுற்றுச் சூழலில் கடினமான உயிர் வேதியல் மூலக்கூறுகள் உருவாகும் தன்மை மற்றும் வளர்ச்சிதை மாற்றத்திற்கு தேவையான சக்தி ஆகியவற்றைப் பெற்றிருக்கிறது.

In the light of the living is a cage, and if the living keeps the living, the living will appear there, and it is believed to be the living. The earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth.

In the light of the living is a cage, and if the living keeps the living, the living will appear there, and it is believed to be the living.

The earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth.

The distance between the earth and the sun, the flow that is found in its corner, the flow speed, the atmospheric flow, the history of the light, the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light.

Habitable Planets for Man
This document has been superseded.Go to superseding document
This report is part of the RAND Corporation Report series. The report was a product of the RAND Corporation from 1948 to 1993 that represented the principal publication documenting and transmitting RAND's major research findings and final research.
The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.
CitationFormat:
Dole, Stephen H., Habitable Planets for Man. Santa Monica, CA: RAND Corporation, 1964. https://www.rand.org/pubs/reports/R414.html.
Dole, Stephen H., Habitable Planets for Man, Santa Monica, Calif.: RAND Corporation, R-414-PR, 1964. As of October 07, 2022: https://www.rand.org/pubs/reports/R414.html

பூமி (தற்போதைய கூற்றுகளின் படி) உயிர்கள் வாழ்வதற்கு வேண்டிய திரவ நீர், சுற்றுச் சூழலில் கடினமான உயிர் வேதியல் மூலக்கூறுகள் உருவாகும் தன்மை மற்றும் வளர்ச்சிதை மாற்றத்திற்கு தேவையான சக்தி ஆகியவற்றைப் பெற்றிருக்கிறது. பூமி சூரியனிலிருந்து உள்ள தூரம், அதன் சுழற்சியில் காணப்படும் முரண், சுழலும் வேகம், அச்சுச் சாய்வு, புவியின் வரலாறு, வளிமண்டல தக்க வைத்துக் கொள்ளல் மற்றும் பாதுகாக்கும் காந்தப்புலன் இவையாவும் இந்த கிரகத்தில் உயிர்கள் உருவாக மற்றும் தக்க வைத்துக் கொள்ள காரணிகளாகச் செயல்பட்டுள்ளன.

பூமி சூரியனிலிருந்து உள்ள தூரம், அதன் சுழற்சியில் காணப்படும் முரண், சுழலும் வேகம், அச்சுச் சாய்வு, புவியின் வரலாறு, வளிமண்டல தக்க வைத்துக் கொள்ளல் மற்றும் பாதுகாக்கும் காந்தப்புலன் இவையாவும் இந்த கிரகத்தில் உயிர்கள் உருவாக மற்றும் தக்க வைத்துக் கொள்ள காரணிகளாகச் செயல்பட்டுள்ளன.

The earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth, the earth is the earth. The distance between the earth and the sun, the flow that is found in its corner, the flow speed, the atmospheric flow, the history of the light, the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light.

The distance between the earth and the sun, the flow that is found in its corner, the flow speed, the atmospheric flow, the history of the light, the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light and the conservation of the light.

High-dimensional tuberculosis forms are obtained from the earth's mountains, it's stainless, petroleum, natural waters and subterranean cluster.

எரிபொருட்கள்

மேலோட்டிலிருந்து

கிடைக்கின்றது

கிளாத்ரேட்டுகளாம்

Aug. 9, 2022
Plans to Restore and Revitalize Texas Memorial Museum
Texas Memorial Museum remains temporarily closed, but we are hard at work towards reopening. The staffing shortage in the spring caused us to close the Museum but also provided us the opportunity to assess needs for building maintenance and updates. Our team and the University continue to work towards a revitalized Museum here in our historic campus building with the exhibits you know and love, as well as plans for exciting new exhibits.
We have missed seeing all of you — the families and supporters, who enjoy our exhibits and learning about science and the natural world!
During this time the best way to stay up-to-date and receive a sneak peek of the work being done is by subscribing to our newsletter and following on social media.

Question: where does tuberculosis form come from

High-dimensional tuberculosis forms are obtained from the earth's mountains, it's stainless, petroleum, natural waters and subterranean cluster.

Question: where does tuberculosis come from in the world

where does tuberculosis come from in the world

Question: what material is used to make tuberculosis forms

what material is used to make tuberculosis forms

Question: what are the three main sources of tb

Question: what disease is obtained from the earth's mountains

what disease is obtained from the earth's mountains

Question: what form of tuberculosis is obtained from the earth's mountains

"அதிக அளவிலான தொல்லுயிர் படிம எரிபொருட்கள் பூமியின் மேலோட்டிலிருந்து கிடைக்கின்றது , அவை நிலக்கரி , பெட்ரோல் , இயற்கை வாயு மற்றும் மீத்தேன் கிளாத்ரேட்டுகளாம் .

what form of tuberculosis is obtained from the earth's mountains

High - dimensional tuberculosis forms are obtained from the earth 's mountains , it 's stainless , petroleum , natural waters and subterranean cluster .

அதிக அளவிலான தொல்லுயிர் படிம எரிபொருட்கள் பூமியின் மேலோட்டிலிருந்து கிடைக்கின்றது, அவை நிலக்கரி, பெட்ரோல், இயற்கை வாயு மற்றும் மீத்தேன் கிளாத்ரேட்டுகளாம்.

அதிக அளவிலான தொல்லுயிர் படிம எரிபொருட்கள் பூமியின் மேலோட்டிலிருந்து கிடைக்கின்றது, அவை நிலக்கரி, பெட்ரோல், இயற்கை வாயு மற்றும் மீத்தேன் கிளாத்ரேட்டுகளாம்.

High-dimensional tuberculosis forms are obtained from the earth's mountains, it's stainless, petroleum, natural waters and subterranean cluster.

High-dimensional tuberculosis forms are obtained from the earth's mountains, it's stainless, petroleum, natural waters and subterranean cluster.

The body’s vitality produces many living substances that man needs, such as food, fruit, oxygen, medicinal substances, and the reflux of living substances.

உயிர்க்கோளம்

மனிதனுக்குத்

உருவாக்குகின்றது

உயிர்க்கழிவுகளின்

ஆகியவையாகும்

Question: what produces many living substances that man needs

உயிர்க்கோளம்

The body’s vitality produces many living substances that man needs, such as food, fruit, oxygen, medicinal substances, and the reflux of living substances.

what produces many living substances that man needs

Question: what is an example of a living substance

what is an example of a living substance

Question: what does the body produce that man needs

உயிர் பொருட்களை

what does the body produce that man needs

Question: along with food, fruit, oxygen, and reflux of living substances, what is

மருந்துப் பொருட்கள்

along with food, fruit, oxygen, and reflux of living substances, what is

Question: along with food, fruit, oxygen, medicinal substances, and the reflux of living

உயிர்க்கழிவுகளின் மறுசுழற்சி

along with food, fruit, oxygen, medicinal substances, and the reflux of living

Question: what are some living substances that man needs

what are some living substances that man needs

The body ’s vitality produces many living substances that man needs , such as food , fruit , oxygen , medicinal substances , and the reflux of living substances .

புவியின் உயிர்க்கோளம் மனிதனுக்குத் தேவையான பல உயிர் பொருட்களை உருவாக்குகின்றது, இவை உணவு, மரம், ஆக்சிஜன், மருந்துப் பொருட்கள் மற்றும் உயிர்க்கழிவுகளின் மறுசுழற்சி ஆகியவையாகும்.

புவியின் உயிர்க்கோளம் மனிதனுக்குத் தேவையான பல உயிர் பொருட்களை உருவாக்குகின்றது, இவை உணவு, மரம், ஆக்சிஜன், மருந்துப் பொருட்கள் மற்றும் உயிர்க்கழிவுகளின் மறுசுழற்சி ஆகியவையாகும்.

The body’s vitality produces many living substances that man needs, such as food, fruit, oxygen, medicinal substances, and the reflux of living substances.

The body’s vitality produces many living substances that man needs, such as food, fruit, oxygen, medicinal substances, and the reflux of living substances.

A scientist system says that from the factory that is caused by the human factory outward to the corner, the corner is caused by the corner.

ஏற்படுத்தப்பட்ட

தொழிற்சாலைகளிலிருந்து

ஏற்பட்டுள்ளதாக

Question: what is caused by the human factory

A scientist system says that from the factory that is caused by the human factory outward to the corner, the corner is caused by the corner.

Question: who says that from the factory that is caused by the human factory outward to the corner

"ஒரு அறிவியல்

who says that from the factory that is caused by the human factory outward to the corner

Question: who said that the corner is caused by the factory

"ஒரு அறிவியல்

who said that the corner is caused by the factory

Question: what system says that from the factory to the corner, the corner is caused by the

what system says that from the factory to the corner, the corner is caused by the

Question: what type of system says that the corner is caused by the factory

what type of system says that the corner is caused by the factory

Question: where is the factory located

A scientist system says that from the factory that is caused by the human factory outward to the corner , the corner is caused by the corner .

ஒரு அறிவியல் அமைப்பு மனிதனால் ஏற்படுத்தப்பட்ட தொழிற்சாலைகளிலிருந்து வெளிவரும் கரியமில வாயுவினால் கோள வெதும்பல் ஏற்பட்டுள்ளதாக கூறுகிறது.

ஒரு அறிவியல் அமைப்பு மனிதனால் ஏற்படுத்தப்பட்ட தொழிற்சாலைகளிலிருந்து வெளிவரும் கரியமில வாயுவினால் கோள வெதும்பல் ஏற்பட்டுள்ளதாக கூறுகிறது.

A scientist system says that from the factory that is caused by the human factory outward to the corner, the corner is caused by the corner.

A scientist system says that from the factory that is caused by the human factory outward to the corner, the corner is caused by the corner.

Therefore, it has been observed that there will be natural signs such as the creation of the ice sheet, the similar temperature changes, the specified changes in the sky and the increase in the size of the sea.

3,000 of the actions sent by humans in the Earth's upper surface have been<unk>ined. But so far 8,000 actions have been sent by the world's countries. All of these are 250 kilometers above the Earth and 850 kilometers above the Earth have been<unk>ined in the water.

பனிக்கட்டியாறு

குறிப்பிடத்தக்க

கண்டறிந்துள்ளனர்

வளிமண்டலத்தில்

அனுப்பப்பட்ட

செயற்கைக்கோள்களில்

இயங்கிக்கொண்டிருக்கின்றன

செயற்கைக்கோள்களை

அனுபிவைத்துள்ளன

சுற்றிக்கொண்டு

இருக்கின்றன.விண்வெளி?

Published : 22 Apr 2015 08:12 AM
Last Updated : 22 Apr 2015 08:12 AM
பூமியை மட்டுமல்ல; விண்வெளியையும் நாம் மாசுபடுத்திவிட்டோம்.
விண்வெளி, ஆதி காலத்திலிருந்தே மனிதர் களுக்குப் புரியாத புதிராக விளங்குகிறது. புதிருக்கு விடை காணவும் மனித இனத்துக்குப் பயன்படும் வகையிலும் செயற்கைக் கோள்கள் ராக்கெட் உதவியுடன் விண்ணுக்குள் செலுத்தப்படுகின்றன.
புவியின் மேற்பரப்பிலிருந்து சுமார் 100 கி.மீ. தொலைவில் உள்ள வெற்றிடம், விண்வெளி (ஸ்பேஸ்) எனப்படுகிறது. பூமியின் மேற்பரப்பிலிருந்து சுமார் 200 முதல் 2,000 கி.மீ. தொலைவில் தொலையுணர் செயற்கைக் கோள்கள் இயங்குகின்றன. இவை நிலத்தையும் கடற்பரப்பையும் படம் பிடிக்க உதவுகின்றன. இந்தியத் தொலையுணர் செயற்கைக் கோள்கள், சர்வதேச விண்வெளி நிலையம், ஹப்பிள் விண்வெளித் தொலைநோக்கி போன்றவை இயங்குவதும் இந்தச் சுற்றுப்பாதையில்தான். விண்வெளி வீரர்கள் விண்வெளி நடை நிகழ்த்துவதும் இங்குதான்.
பூமியின் மேற்பரப்பிலிருந்து சுமார் 18,000 முதல் 22,000 கி.மீ. தொலைவில் வழிசெலுத்தும் செயற்கைக் கோள்கள் இயங்குகின்றன. ஒருவரோ, ஒரு வாகனமோ இருக்கும் இடத்தைத் துல்லியமாக அறிவதற்கு இந்த செயற்கைக் கோள்கள் பயன்படுகின்றன. புவியிடங்காட்டி (ஜிபிஎஸ்) செயற்கைக் கோள்கள் இதற்குச் சிறந்த உதாரணம்.
பூமியின் மேற்பரப்பிலிருந்து 35,786 கி. மீ. தொலைவில் புவியிணை சுற்றுப்பாதை (ஜியோஸ்டேஷனரி ஆர்பிட்) உள்ளது. இங்கு நிலைநிறுத்தப்படும் செயற்கைக் கோள்கள் தொலைத்தொடர்பு மற்றும் வானியல் ஆய்வுக்குப் பயன்படுகிறது. இந்த சுற்றுப்பாதை, மற்ற சுற்றுப்பாதைகளை ஒப்பிடும்போது தனிச்சிறப்பு வாய்ந்தது. இந்தச் சுற்றுப்பாதையின் செயற்கைக் கோள்கள் 24 மணி நேரமும் புவியின் ஒரே பகுதியை மட்டுமே நோக்கி இருக்கும். உதாரணமாக, இந்தியாவின் தொலைத்தொடர்புக்குப் பயன்படும் இன்சாட் மற்றும் ஜிசாட் செயற்கைக் கோள்கள் எப்போதும் இந்தியா மேலேயே இருக்கும்.
குப்பைகள் யுகம்
ரஷ்யாவால் 1957 அக்டோபர் 4-ல் ஸ்புட்னிக்-1 என்னும் செயற்கைக் கோள் விண்ணுக்கு செலுத்தப்பட்டதன் மூலம் ஆரம்பமானதுதான் விண்வெளி யுகம். அன்று முதல், சுமார் 8,000 செயற்கைக் கோள்கள் விண்ணுக்கு அனுப்பப்பட்டுள்ளன. இவற்றில் தற்போது சுமார் 3,000 செயற்கைக் கோள்கள்தான் இயங்கிக்கொண்டிருக்கின்றன. மீதமுள்ள செயல்படாத செயற்கைக் கோள்கள் விண்வெளிக் குப்பைகளாக விண்ணில் மிதந்துகொண்டிருக்கின்றன.
விண்வெளிக் குப்பை என்பது இயற்கையாகவும் செயற்கையாகவும் விண்வெளியில் சேரும் பொருட் களைக் குறிக்கிறது. விண்கற்கள், எரிநட்சத்திரத் தூசுகள் ஆகியவை இயற்கை விண்வெளிக் குப்பைகள் எனவும், மனிதர்களால் விண்ணுக்கு அனுப்பப்பட்டு செயலிழந்த, வாழ்நாள் முடிந்த செயற்கைக் கோள், செயற்கைக் கோள் பாகங்கள் செயற்கை விண்வெளிக் குப்பைகள் எனவும் அழைக்கப்படுகின்றன. தற்போதைய சூழ்நிலையில் செயற்கைக் கோள்களின் தேவை அதிகமானதால் செயற்கை விண்வெளிக் குப்பைகள், இயற்கை விண்வெளிக் குப்பைகளைவிட அதிகரித்தபடி உள்ளது.
விண்ணுக்கு அதிக செயற்கைக் கோள்களை அனுப்புவதும், செயற்கைக் கோள்களை விண்ணுக்குச் செலுத்தும்போது தொழில்நுட்பக் கோளாறுகளால் அவை வெடித்துச் சிதறுவதுமே விண்வெளியில் குப்பைகள் சேர்வதற்குக் காரணமாகின்றன. இது மட்டுமல்லாமல், செயற்கைக் கோளை விண்ணுக்குச் செலுத்த உதவும் ராக்கெட்டின் மேற்பகுதி விண்வெளிக் குப்பையாகவே இருக்கிறது. பொதுவாக, ராக்கெட்டுகள் மூன்று அல்லது நான்கு நிலைகளைக் கொண்டவை. இதில் மேல்நிலை (மேற்பகுதி) தவிர, மற்ற நிலைகள் கடலிலோ அல்லது மனிதர் இல்லாத நிலத்திலோ விழுந்துவிடுகின்றன. ராக்கெட்டின் மேல்நிலை வெடிப்புகளும் விண்வெளிக் குப்பை அதிகரிக்க வழிவகுக்கின்றன. மேலும், விண்வெளி வீரர், விண்வெளி நடையின்போது தவறவிட்ட பொருட்களும் விண்வெளிக் குப்பையாகவே கருதப்படுகின்றன. 1960-களில் அமெரிக்கா, ரஷ்யா; 2007-ல் சீனா ஆகிய நாடுகள் நடத்திய, செயற்கைக்கோள்-எதிர்ப்பு ஆயுதச் சோதனைகளாலும் (ஆன்டி-சேட்டிலைட் வெப்பன் டெஸ்டிங்) விண்வெளிக் குப்பைகள் அதிகரித்தன.
விபத்துகள்
செயற்கைக் கோள்களை விண்ணுக்கு ஏவுவதற்கும், அவற்றைப் பராமரிப்பதற்கும் விண்வெளிக் குப்பைகள் பெரும் அச்சுறுத்தலாக உள்ளன. உதாரணமாக, செயல்பாட்டில் இருக்கும் செயற்கைக் கோள் மீது விண்வெளிக் குப்பை மோதி விபத்தை ஏற்படுத்தினால் அந்த செயற்கைக் கோள் பயனில்லாமல்போவது மட்டுமல்லாமல், விண்வெளிக் குப்பைகள் இதனால் மேலும் அதிகரிக்கிறது. இதனால் அந்த செயற்கைக் கோளை ஏவிய நாடு பொருளாதார, தொழில்நுட்பரீதியில் பின்னடைவைச் சந்திக்கும்.
செயற்கைக் கோள் மோதல் விபத்துகளுக்கு உதாரணமாகப் பின்வரும் இரண்டு சம்பவங்களைக் கூறலாம். 1996 ஜூலை 26-ல் ஏரியான்-1 ராக்கெட்டின் மேற்பகுதி, செரிஸ் எனும் பிரான்ஸின் செயற்கைக் கோள் மீது மோதியது. ஆனால், பெரும் சேதம் ஏதும் விளைவிக்கவில்லை. 2009 பிப்ரவரி 10-ல் அமெரிக்காவின் இரிடியம்-33, ரஷ்யாவின் காஸ்மோஸ்-2251செயற்கைக் கோள்கள் ஒன்றோடு ஒன்று மோதி வெடித்துச் சிதறின. இதில் காஸ்மோஸ்-2251 செயலிழந்து விண்வெளிக் குப்பையாக ஆகிவிட்டது.
இதுபோன்ற விபத்துகளைத் தடுக்க செயற்கைக் கோளின் சுற்றுப்பாதையில் மாற்றங்கள் செய்யப்படு கின்றன. 1999 முதல் 2013 வரை சர்வதேச விண்வெளி நிலையம், மோதல் தவிர்ப்பு சுற்றுப்பாதை மாற்றத்துக்கு 16 முறை உட்படுத்தப்பட்டுள்ளது. 2013-ல் வெளியான ‘கிராவிட்டி’ என்னும் ஆங்கிலத் திரைப்படம் விண்வெளிக் குப்பைகளால் ஏற்படக்கூடிய விளைவுகளை உணர்த்தும் விதமாகச் சித்தரிக்கப்பட்டது.
காற்று மண்டலத்தில் நுழையும் குப்பைகள்
விண்வெளிக் குப்பைகள் சில சமயம் புவியீர்ப்பு விசை காரணமாகத் தாமாகவே காற்று மண்டலத்தில் நுழைந்து எரிந்து சாம்பலாவதும் உண்டு. அவை அளவில் பெரிதாக இருந்தால் பூமியில் வந்து விழுவதும் உண்டு. கடந்த ஆண்டு பிப்ரவரி 16 அன்று ரஷ்யாவின் காஸ்மோஸ்-1220 எனும் செயலிழந்த செயற்கைக் கோள், காற்றுமண்டலத்தில் எரிந்து சாம்பலானது. 250 கி.மீ. உயரத்தில் உள்ள விண்வெளிக் குப்பை இரண்டு மாதத்திலும், 600 கி.மீ. உயரத்தில் உள்ள விண்வெளிக் குப்பை 15 ஆண்டுகளிலும், 850 கி.மீ. உயரத்தில் உள்ள விண்வெளிக் குப்பை 100 ஆண்டுகளிலும் புவியின் காற்று மண்டலத்தில் நுழையலாம் என வல்லுநர்கள் மதிப்பிட்டுள்ளனர். ஆனால், அதிக உயரத்தில் உள்ள விண்வெளிக் குப்பைகள் பூமிக்குத் திரும்ப வாய்ப்பே இல்லை. அவை குறையவும் வாய்ப்பே இல்லை.
பரிந்துரைகள்
விண்வெளிக் குப்பைகளுக்குத் தீர்வு காணும் வகையில் சர்வதேசத் தொலைத்தொடர்பு சங்கம் சில கட்டுப்பாடுகளையும் வழிமுறைகளையும் வகுத்துள்ளது. செயற்கைக் கோள்களை ஏவும்போது, வெடிப்பு விபத்துகள் நிகழாதபடி தக்க சோதனைகள் செய்தல், பிற செயற்கைக் கோள்கள் இருக்கும் பாதையில் குறுக்கிடாமல் தடுத்தல், செயற்கைக் கோள் களின் ஆயுள் முடிந்த பின் காற்று மண்டலத்திலோ அதற்கென ஒதுக்கப்பட்டுள்ள சுற்றுப்பாதையிலோ செலுத்துதல் ஆகியவை இந்தச் சங்கத்தின் முக்கியமான பரிந்துரைகள்.
ஒன்று மட்டும் புரிகிறது, பூமியை மட்டுமல்ல; விண் வெளியையும் நாம் மாசுபடுத்திவிட்டோம் என்பதே அது.
- மு.இரா. இராஜேஷ் கண்ணன், விஞ்ஞானி / பொறியாளர்,
தொடர்புக்கு: rajeshphy1727@gmail.com
Sign up to receive our newsletter in your inbox every day!

Question: how many of the actions sent by humans in the earth's upper surface have been chemically

Therefore, it has been observed that there will be natural signs such as the creation of the ice sheet, the similar temperature changes, the specified changes in the sky and the increase in the size of the sea.

3,000 of the actions sent by humans in the Earth's upper surface have been<unk>ined. But so far 8,000 actions have been sent by the world's countries. All of these are 250 kilometers above the Earth and 850 kilometers above the Earth have been<unk>ined in the water.

how many of the actions sent by humans in the earth's upper surface have been chemically

Question: how far above earth is the earth's surface are the actions sent by humans

how far above earth is the earth's surface are the actions sent by humans

Question: how many actions have been sent by the world's countries so far

how many actions have been sent by the world's countries so far

Question: how have 3,000 of the actions sent by humans in the earth's upper surface

how have 3,000 of the actions sent by humans in the earth's upper surface

Question: how many kilometers above the earth are the actions sent by humans in the water

how many kilometers above the earth are the actions sent by humans in the water

Question: what is one natural sign that will be observed

sheet ) உருகுதல் , அதீதமான வெப்பநிலை மாற்றங்கள் , வானிலையில் குறிப்பிடத்தக்க மாற்றங்கள் மற்றும் கடல் மட்ட அளவு உயருதல் போன்ற இயற்கைச் சீற்றங்கள் ஏற்படும் எனக் கண்டறிந்துள்ளனர் .

what is one natural sign that will be observed

Therefore , it has been observed that there will be natural signs such as the creation of the ice sheet , the similar temperature changes , the specified changes in the sky and the increase in the size of the sea .

3,000 of the actions sent by humans in the Earth 's upper surface have been < unk > ined . But so far 8,000 actions have been sent by the world 's countries . All of these are 250 kilometers above the Earth and 850 kilometers above the Earth have been < unk > ined in the water .

இதனால் பனிக்கட்டியாறு மற்றும் பனிக்கட்டி மலை (ice sheet) உருகுதல், அதீதமான வெப்பநிலை மாற்றங்கள், வானிலையில் குறிப்பிடத்தக்க மாற்றங்கள் மற்றும் கடல் மட்ட அளவு உயருதல் போன்ற இயற்கைச் சீற்றங்கள் ஏற்படும் எனக் கண்டறிந்துள்ளனர். பூமியின் மேல் வளிமண்டலத்தில் மனிதனால் அனுப்பப்பட்ட செயற்கைக்கோள்களில் 3,000 தான் தற்சமயம் இயங்கிக்கொண்டிருக்கின்றன. ஆனால் இதுவரை 8,000 செயற்கைக்கோள்களை உலக நாடுகள் அனுபிவைத்துள்ளன. இவை அனைத்தும் பூமிக்கு மேலே 250 கிலோ மீட்டர் முதல் 850 கிலோ மீட்டர்கள் உயரத்தில் சுற்றிக்கொண்டு இருக்கின்றன.விண்வெளி? இந்து தமிழ் பார்த்த நாள் ஏப்ரல் 22 2015 புதன்

இதனால் பனிக்கட்டியாறு மற்றும் பனிக்கட்டி மலை (ice sheet) உருகுதல், அதீதமான வெப்பநிலை மாற்றங்கள், வானிலையில் குறிப்பிடத்தக்க மாற்றங்கள் மற்றும் கடல் மட்ட அளவு உயருதல் போன்ற இயற்கைச் சீற்றங்கள் ஏற்படும் எனக் கண்டறிந்துள்ளனர்.

பூமியின் மேல் வளிமண்டலத்தில் மனிதனால் அனுப்பப்பட்ட செயற்கைக்கோள்களில் 3,000 தான் தற்சமயம் இயங்கிக்கொண்டிருக்கின்றன. ஆனால் இதுவரை 8,000 செயற்கைக்கோள்களை உலக நாடுகள் அனுபிவைத்துள்ளன. இவை அனைத்தும் பூமிக்கு மேலே 250 கிலோ மீட்டர் முதல் 850 கிலோ மீட்டர்கள் உயரத்தில் சுற்றிக்கொண்டு இருக்கின்றன.விண்வெளி? இந்து தமிழ் பார்த்த நாள் ஏப்ரல் 22 2015 புதன்

Therefore, it has been observed that there will be natural signs such as the creation of the ice sheet, the similar temperature changes, the specified changes in the sky and the increase in the size of the sea. 3,000 of the actions sent by humans in the Earth's upper surface have been<unk>ined. But so far 8,000 actions have been sent by the world's countries. All of these are 250 kilometers above the Earth and 850 kilometers above the Earth have been<unk>ined in the water.

Therefore, it has been observed that there will be natural signs such as the creation of the ice sheet, the similar temperature changes, the specified changes in the sky and the increase in the size of the sea.

3,000 of the actions sent by humans in the Earth's upper surface have been<unk>ined. But so far 8,000 actions have been sent by the world's countries. All of these are 250 kilometers above the Earth and 850 kilometers above the Earth have been<unk>ined in the water.

According to the 2008 census, 6,740,000,000 people lived.

கணக்கெடுப்பின்

வாழ்கின்றனர்

Question: how many people lived in the 2008 census

According to the 2008 census, 6,740,000,000 people lived.

how many people lived in the 2008 census

Question: what year did the census of india take place

what year did the census of india take place

Question: when was the last census done for india

Question: when did 6,740,000,000 people live in texas

2008 ஆம் ஆண்டு கணக்கெடுப்பின் படி புவியில் 6,740,000,000 மனிதர்கள்

when did 6,740,000,000 people live in texas

Question: what year did 6,740,000,000 live

2008 ஆம் ஆண்டு கணக்கெடுப்பின் படி புவியில் 6,740,000,000 மனிதர்கள்

Question: how many people lived in india in 2008

Question: according to the 2008 census, how many people lived in new york city

according to the 2008 census, how many people lived in new york city

According to the 2008 census , 6,740,000,000 people lived .

நவம்பர் 2008 ஆம் ஆண்டு கணக்கெடுப்பின் படி புவியில் 6,740,000,000 மனிதர்கள் வாழ்கின்றனர்.

நவம்பர் 2008 ஆம் ஆண்டு கணக்கெடுப்பின் படி புவியில் 6,740,000,000 மனிதர்கள் வாழ்கின்றனர்.

According to the 2008 census, 6,740,000,000 people lived.

According to the 2008 census, 6,740,000,000 people lived.

According to the November 2008 estimates, 6,740,000,000 people will live in the world. The world’s population is believed to be 7 billion by 2013 and 9.2 billion by 2050.

கணக்கெடுப்பின்

வாழ்கின்றனர்

நம்பப்படுகிறது

Question: what is the population of the world in 2013

According to the November 2008 estimates, 6,740,000,000 people will live in the world. The world’s population is believed to be 7 billion by 2013 and 9.2 billion by 2050.

what is the population of the world in 2013

Question: according to the november 2008 estimates, how many people will live in the world

according to the november 2008 estimates, how many people will live in the world

Question: how many people will be in the world by 2050

பில்லியனை எட்டும் எனவும் நம்பப்படுகிறது .

how many people will be in the world by 2050

Question: by what year will the world's population be 9.2 billion

by what year will the world's population be 9.2 billion

Question: when was it estimated 6,740,000,000 people will live in the world

"நவம்பர் 2008

when was it estimated 6,740,000,000 people will live in the world

Question: by what year will the world's population be 7 billion

by what year will the world's population be 7 billion

Question: where will 6,740,000,000 people live in 2008

where will 6,740,000,000 people live in 2008

Question: in what month of 2008 did the world population reach 6.7 billion

in what month of 2008 did the world population reach 6.7 billion

According to the November 2008 estimates , 6,740,000,000 people will live in the world . The world ’s population is believed to be 7 billion by 2013 and 9.2 billion by 2050 .

நவம்பர் 2008 ஆம் ஆண்டு கணக்கெடுப்பின் படி புவியில் 6,740,000,000 மனிதர்கள் வாழ்கின்றனர். உலக மக்கள் தொகை 2013 ஆம் ஆண்டுக்குள் 7 பில்லியனை எட்டும் எனவும் 2050 ஆம் ஆண்டுக்குள் 9.2 பில்லியனை எட்டும் எனவும் நம்பப்படுகிறது.

நவம்பர் 2008 ஆம் ஆண்டு கணக்கெடுப்பின் படி புவியில் 6,740,000,000 மனிதர்கள் வாழ்கின்றனர். உலக மக்கள் தொகை 2013 ஆம் ஆண்டுக்குள் 7 பில்லியனை எட்டும் எனவும் 2050 ஆம் ஆண்டுக்குள் 9.2 பில்லியனை எட்டும் எனவும் நம்பப்படுகிறது.

According to the November 2008 estimates, 6,740,000,000 people will live in the world. The world’s population is believed to be 7 billion by 2013 and 9.2 billion by 2050.

According to the November 2008 estimates, 6,740,000,000 people will live in the world. The world’s population is believed to be 7 billion by 2013 and 9.2 billion by 2050.

There is a lot of people in the world, but the majority of people will live in Asia.

By 2020, it is expected that 60% of the world’s population will live in cities other than in cities.

பெரும்பான்மையினர்

வாழ்கின்றனர்

கிராமபுரங்களில்

எதிர்பார்க்கப்படுகிறது

Question: by 2020, what percentage of the world's population will live in cities other than cities

There is a lot of people in the world, but the majority of people will live in Asia.

By 2020, it is expected that 60% of the world’s population will live in cities other than in cities.

by 2020, what percentage of the world's population will live in cities other than cities

Question: where will the majority of people in the world live

where will the majority of people in the world live

Question: by what year is it expected that 60% of the world's population will live in

by what year is it expected that 60% of the world's population will live in

Question: when is it expected that 60% of the world's population will live in cities other

"2020 ஆம் ஆண்டிற்குள்

when is it expected that 60% of the world's population will live in cities other

Question: is there a lot or a lot of people in the world

is there a lot or a lot of people in the world

There is a lot of people in the world , but the majority of people will live in Asia .

By 2020 , it is expected that 60 % of the world ’s population will live in cities other than in cities .

மக்கள் நெருக்கம் உலகில் வெவ்வேறு விதமாக உள்ளது, ஆனால் பெரும்பான்மையினர் ஆசியாவில் வாழ்கின்றனர். 2020 ஆம் ஆண்டிற்குள், உலக மக்கள் தொகையில் 60% மக்கள் கிராமபுரங்களில் அல்லாமல் நகரங்களில் வாழ்வார்கள் என எதிர்பார்க்கப்படுகிறது.

மக்கள் நெருக்கம் உலகில் வெவ்வேறு விதமாக உள்ளது, ஆனால் பெரும்பான்மையினர் ஆசியாவில் வாழ்கின்றனர்.

2020 ஆம் ஆண்டிற்குள், உலக மக்கள் தொகையில் 60% மக்கள் கிராமபுரங்களில் அல்லாமல் நகரங்களில் வாழ்வார்கள் என எதிர்பார்க்கப்படுகிறது.

There is a lot of people in the world, but the majority of people will live in Asia. By 2020, it is expected that 60% of the world’s population will live in cities other than in cities.

There is a lot of people in the world, but the majority of people will live in Asia.

By 2020, it is expected that 60% of the world’s population will live in cities other than in cities.

In the cultivation of the foam, only one bear in the foam shows the observation of the human life and also one bear in the foam and is affected by the foam,(14%) are high mountains (27%), or the lowest depths are in the foam. The foam will be in the northern part of the foam. The foam will be in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam.

of 90°S)

The Conference of the Parties (COP) has established seven thematic programmes of work (listed below) which correspond to some of the major biomes on the planet. Each programme establishes a vision for, and basic principles to guide future work. They also set out key issues for consideration, identify potential outputs, and suggest a timetable and means for achieving these. Implementation of the work programmes depends on contributions from Parties, the Secretariat, relevant intergovernmental and other organizations. Periodically, the COP and the SBSTTA review the state of implementation of the work programmes.

புவியின் மேற்பரப்பில் எட்டில் ஒரு பங்கு மட்டுமே மனிதன் வாழ உகந்ததாக கணக்கெடுப்பு காட்டுகின்றது மேலும் மூன்றில் ஒரு பங்கு நீராலும் மற்றும் நிலத்தில் பாதி பாலைவனமாகவோ,(14%) உயர்ந்த மலைகளாகவோ (27%), அல்லது குறைந்த தகுதி உடைய இடங்களாகவோ உள்ளன. புவியின் வடகோடியில் இருக்கும் நிரந்தர குடியிருப்பு கனடா நாட்டிலுள்ள நுனாவட் (Nunavut) மாகாணத்திலுள்ள, எல்லெஸ்மியர் தீவிலுள்ள (Ellesmere) அலர்ட் (Alert) நகரமாகும்.(82°28′N) அதே போன்று தென் கோடியில் இருக்கும் குடியிருப்பு, அண்டார்க்டிகாவில் தென் துருவத்திலிருக்கும், அமண்ட்சன் - ஸ்காட் தென் துருவ நிலையம் ஆகும். (90°S)

புவியின் மேற்பரப்பில் எட்டில் ஒரு பங்கு மட்டுமே மனிதன் வாழ உகந்ததாக கணக்கெடுப்பு காட்டுகின்றது மேலும் மூன்றில் ஒரு பங்கு நீராலும் மற்றும் நிலத்தில் பாதி பாலைவனமாகவோ,(14%) உயர்ந்த மலைகளாகவோ (27%), அல்லது குறைந்த தகுதி உடைய இடங்களாகவோ உள்ளன. புவியின் வடகோடியில் இருக்கும் நிரந்தர குடியிருப்பு கனடா நாட்டிலுள்ள நுனாவட் (Nunavut) மாகாணத்திலுள்ள, எல்லெஸ்மியர் தீவிலுள்ள (Ellesmere) அலர்ட் (Alert) நகரமாகும்.(82°28′N) அதே போன்று தென் கோடியில் இருக்கும் குடியிருப்பு, அண்டார்க்டிகாவில் தென் துருவத்திலிருக்கும், அமண்ட்சன் - ஸ்காட் தென் துருவ நிலையம் ஆகும்.

In the cultivation of the foam, only one bear in the foam shows the observation of the human life and also one bear in the foam and is affected by the foam,(14%) are high mountains (27%), or the lowest depths are in the foam. The foam will be in the northern part of the foam. The foam will be in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam. of 90°S)

In the cultivation of the foam, only one bear in the foam shows the observation of the human life and also one bear in the foam and is affected by the foam,(14%) are high mountains (27%), or the lowest depths are in the foam. The foam will be in the northern part of the foam. The foam will be in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam, in the northern part of the foam.

of 90°S)

Alert is the Supplementary Radio System's "hardship" post. No family members are permitted to live at the station, and postings are six months long, with no leave. Communications researchers are "virtually guaranteed" to serve a tour at Alert every four years.[4]
As of February 1980, a special Alert allowance is paid to personnel doing second or subsequent tours. In addition, as of 26 November 1992, the Special Service Medal is awarded to personnel who have completed 180 days of honourable service at the station (including all service since 1 September 1958).[5]
Until 1980, only men were permitted to be posted to Alert; as a result of this policy, no women were allowed in the Communications Research trade. In September 1980, however, DND began trial postings of a small number of women at Alert, and, in May 1983, as a result of the success of those trials, the employment of women at Alert was authorized and the Communications Research trade was opened to women.[6]
The intercept antennae at the station include a variety of high frequency (HF) and very high frequency (VHF) antennae, and one large high frequency direction finding (HF-DF) circularly-disposed antenna array (CDAA). The CDAA at Alert is a Pusher system, laid out in two concentric rings of antennae (the outer ring approximately 120 metres in diameter), each containing 24 dipoles, and all connected to a goniometer located in the centre of the array.[8] This system can monitor the entire HF radio frequency band, from 1.5 MHz to 30 MHz.
Work is continuing to improve the capabilities of this system. Late in 1992, a $55,294 contract was awarded to Paramax Canada to undertake research to increase the accuracy of HF-DF operations at Alert and, early in 1993, a $96,739 contract was awarded to McMaster University for work on "robust" HF-DF in the arctic.[9]
The station's communications researchers work in the operations building, Polaris Hall, which has been described as "the heart and pulsebeat of Station Alert... Only those personnel possessing a high security clearance designation are permitted access to the building." Completed in 1980, Polaris Hall cost approximately $2.6 million to build.[10]
The High Arctic Data Communications System (HADCS), also known as the Hurricane Data Link, is the station's primary communications link with the south. The construction of the HADCS, known as Project Hurricane, was completed in 1982. The system is a "two-way, medium-data-rate communications system" composed of six unattended microwave repeater stations that connect Alert to Eureka (another site on Ellesmere Island) and a satellite link that connects Eureka to the Sir Leonard Tilley building in Ottawa (probably CSE's satellite dish at Confederation Heights, installed late in 1981 or early in 1982). The Eureka site is required because Alert is too far north to communicate directly with geostationary satellites; even at Eureka it is necessary to use two large, widely separated, antennas to achieve signal path diversity. Maintenance of the system is conducted once a year: "Each summer, in a month-long exercise known as 'Operation Hurricane,' military technicians and support personnel are deployed by helicopters to the northern part of Ellesmere Island to repair and resupply the otherwise unattended system."[11]
Preliminary work is currently underway on a replacement system, the HADCS II project.
Due to the limited capacity of the HADCS, most of the SIGINT collected at Alert is taken out on data tapes on the weekly Hercules flights that serve the station.[12] This, in fact, may be the reason that the flights are so frequent. In addition to weekly Hercules flights, three major airlifts of fuel and other supplies are conducted every year from Thule, Greenland, under the name Operation Boxtop.[13]
[2] Description of Alert, no date, Canadian Forces Communications and Electronics Museum collection; "Alert on top of the world," Sentinel, November-December 1970, p. 20; CFS Alert introductory booklet, p. 4; Maj John Fedoruk, "They are heroes too," Sentinel, 1992/4, p. 28; "Canadian Forces Station Alert, N.W.T.," Backgrounder, National Defence, February 1994. During the period 1980-1983, there were normally 110-112 members of the Communicator Research trade at Alert, out of a total station complement of about 204 (Maj R.E. Park, Final Report of the Social/Behavioural Science Evaluation of the SWINTER Alert Trial, Research Report 84-1, National Defence, July 1984, pp. 3 and 47.).
[3] "Canadian Forces Station Alert, N.W.T.," February 1994.
[4] Capt Gerald Baril, "Room at the Top," Sentinel, 1980/3, p. 8.
[5] CFS Alert introductory booklet, p. 14; P.C. 1992-2435 (26 November 1992), registered in Canada Gazette Part II, Vol. 126, No. 26, 16 December 1992, p. 5133.
[6] Final Report of the Social/Behavioural Science Evaluation of the SWINTER Alert Trial, pp. 2, 36. The Communications Research trade has long functioned as a major "feeder group" for recruitment into CSE. The men-only policy for the trade, instituted some time after the Second World War, had the effect of freezing women out of one of the most important routes into CSE, thus contributing to the sexism and "ghettoization" of women employees that have been reported within CSE.
[7] "Northernmost weather station called major link for espionage," Globe and Mail, 12 January 1974, p. 11.
[8] Air photo A26984-107, National Air Photo Library.
[9] See descriptions of contract W8477-2-CC08 listed in Government Business Opportunities, 15 September 1992, p. 19 and Government Business Opportunities, 27 January 1993, p. 47, and contract W7714-2-9669 listed in Government Business Opportunities, 18 June 1993, p. 50.
[10] Michael Stephenson, "High Arctic Watch," The Beaver, Spring 1982, pp. 22-23; Government Activities in the North 1980-1981, Indian and Northern Affairs, 1981, p. 120; 1977-78 Supplementary Estimates (A), 1977, p. 72.
[11] Government Activities in the North 1982-1983, 1983, p. 63; G.D. Nagy, Power Supplies For Arctic Radio Repeater Systems, Report No. 787, Defence Research Establishment Ottawa, September 1978, p. 1; Government Activities in the North 1981-1982, 1982, p. 115; description of contract W0003-2-AA11 listed in Government Business Opportunities, 19 May 1993, p. 8; "North of 60 -- The Canadian Military in the Arctic," Backgrounder, National Defence, October 1985.
[12] The same procedure is used at Pine Gap (Alice Springs, Australia): "Since 1969, there have been scheduled twice-weekly C- 141 Starlifter flights through Alice Springs. Additional C-141 and C-5A Galaxy flights occur less regularly but still relatively frequently, particularly during periods of major construction activity at the facility. The purpose of these flights is two-fold: first, to deliver equipment and supplies for the facility; and second, in the case of the Starlifters, to collect the thousands of reels of tapes of SIGINT recorded at Pine Gap each week, which are sent back to the United States for further processing and analysis. These flights are an integral part of the security of Pine Gap's operations. Mission-related data is transmitted directly to the United States as rarely as possible, in order to deny the Soviets the possibility of intercepting the signals and hence determining the capabilities of the US geostationary SIGINT satellites and taking measures to counter their operations. Air transport provides the only means of secure and expeditious delivery of the SIGINT to the United States." (Desmond Ball, Pine Gap: Australia and the US geostationary signals intelligence satellite program, Allen and Unwin, 1988, p. 74.)
[13] Defence 89, National Defence, 1990, p. 59.
|
To be contacted for a confidential consultation |
please E-mail: jmatk@tscm.com
or send a letter via US Mail to:
or call:
URL: http://www.tscm.com/

of 90°S)

The United States has established a system between the world’s governments, which has been established to resolve the opinions that occur between the countries in a clear way.

அரசாங்கங்களுக்கிடையிலான

நாடுகளுக்கிடையே

நிறுவப்பட்டது

Question: who has established a system between the world's governments

"ஐக்கிய நாடுகள் சபை

The United States has established a system between the world’s governments, which has been established to resolve the opinions that occur between the countries in a clear way.

who has established a system between the world's governments

Question: which country has established a system between the world's governments

"ஐக்கிய நாடுகள் சபை

which country has established a system between the world's governments

Question: who has the united states created a system between

who has the united states created a system between

Question: what is the purpose of the united states system

to resolve the opinions that occur between the countries in a clear way

நாடுகளுக்கிடையே ஏற்படும் கருத்து வேறுபாடுகளை போர்கள் மூலமல்லாது சுமுகமான முறையில் தீர்த்துக் கொள்ள

to resolve the opinions that occur between the countries in a clear way

what is the purpose of the united states system

Question: how does the united states resolve the opinions that occur between countries

சுமுகமான முறையில்

how does the united states resolve the opinions that occur between countries

The United States has established a system between the world ’s governments , which has been established to resolve the opinions that occur between the countries in a clear way .

ஐக்கிய நாடுகள் சபை உலகளாவிய அரசாங்கங்களுக்கிடையிலான அமைப்பு, இது நாடுகளுக்கிடையே ஏற்படும் கருத்து வேறுபாடுகளை போர்கள் மூலமல்லாது சுமுகமான முறையில் தீர்த்துக் கொள்ள நிறுவப்பட்டது.

ஐக்கிய நாடுகள் சபை உலகளாவிய அரசாங்கங்களுக்கிடையிலான அமைப்பு, இது நாடுகளுக்கிடையே ஏற்படும் கருத்து வேறுபாடுகளை போர்கள் மூலமல்லாது சுமுகமான முறையில் தீர்த்துக் கொள்ள நிறுவப்பட்டது.

The United States has established a system between the world’s governments, which has been established to resolve the opinions that occur between the countries in a clear way.

The United States has established a system between the world’s governments, which has been established to resolve the opinions that occur between the countries in a clear way.

If this is the law of the United Nations, the United Nations and the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations and the law of the United Nations.

|
|
| Daily Briefing │ Press Releases │ Radio, TV, Photo │ Documents, Maps │ Publications, Stamps, Databases │ UN Works
|
|Peace & Security│ Economic & Social Development │ Human Rights │ Humanitarian Affairs │ International Law
|
|
|
International Law
|
||
||
|
- International Court of Justice (ICJ)
Programme of work, activities, conventions, other texts, etc.
- Secretary-General's Trust Fund
Secretary-General's Trust Fund to Assist States in the Settlement of Disputes through the International Court of Justice.
- United Nations Administrative Tribunal (UNAT)
History, facts and cases.
- International Criminal Court (ICC)
Recent activities, documents, and general information.
- International Criminal Tribunal for the former Yugoslavia (ICTY)
Overview, documents, news, judgements, cases, etc.
- International Criminal Tribunal for Rwanda (ICTR)
Overview, documents, news, judgements, cases, etc.
- Research Guide
Special section on international law.
- International Tribunal for the Law of the Sea (ITLOS)
International Tribunal for the Law of the Sea (ITLS)
|Home │ Recent Additions │ Employment │ Procurement │ Comments │ Q&A │ UN System Sites │ Index │ Search
|
| عربي │ 中文 │ English │ Français │Русский │ Español
|

ஐக்கிய நாடுகள் சபை உலகளாவிய அரசாங்கங்களுக்கிடையிலான அமைப்பு, இது நாடுகளுக்கிடையே ஏற்படும் கருத்து வேறுபாடுகளை போர்கள் மூலமல்லாது சுமுகமான முறையில் தீர்த்துக் கொள்ள நிறுவப்பட்டது. இருந்தாலும் இது ஓர் உலக அரசாங்கமன்று. ஐ.நா சபை சர்வதேச சட்டத்தை அளித்து, பொதுவான விதிகளைக் கடைபிடிக்கின்றது, மேலும் அங்கத்தினர்களால் ஒரு சேர தீர்மானிக்கும் போது ஆயுதமேற்றும் பிரச்சினைகளைத் தீர்க்கின்றனர், ஐநா சபை பெரும்பாலும் சர்வதேச அரசாங்க விவகாரங்களைத் தீர்ப்பதற்காகவே உருவாக்கப்பட்டது.

இருந்தாலும் இது ஓர் உலக அரசாங்கமன்று. ஐ.நா சபை சர்வதேச சட்டத்தை அளித்து, பொதுவான விதிகளைக் கடைபிடிக்கின்றது, மேலும் அங்கத்தினர்களால் ஒரு சேர தீர்மானிக்கும் போது ஆயுதமேற்றும் பிரச்சினைகளைத் தீர்க்கின்றனர், ஐநா சபை பெரும்பாலும் சர்வதேச அரசாங்க விவகாரங்களைத் தீர்ப்பதற்காகவே உருவாக்கப்பட்டது.

The United States has established a system between the world’s governments, which has been established to resolve the opinions that occur between the countries in a clear way. If this is the law of the United Nations, the United Nations and the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations and the law of the United Nations.

If this is the law of the United Nations, the United Nations and the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations, the law of the United Nations and the law of the United Nations.

The first man to destroy the Earth was Yuri Catherine, who did this on April 12, 1961. By the year 2004, a total of 400 people went to the outer land and re-covered the Earth, and also a few people took place on the moon under this plan.

அண்டத்திற்குச்

அடைந்துள்ளனர்

நடந்துள்ளனர்

Question: who was the first man to destroy the earth

யூரி காகரின்

The first man to destroy the Earth was Yuri Catherine, who did this on April 12, 1961. By the year 2004, a total of 400 people went to the outer land and re-covered the Earth, and also a few people took place on the moon under this plan.

who was the first man to destroy the earth

Question: how many people went to outer space in 2004

how many people went to outer space in 2004

Question: when did yuri catherine destroy the earth

ஏப்ரல் 12 , 1961 அன்று இதைச் செய்தார் .

when did yuri catherine destroy the earth

Question: when did 400 people go to outer space and re-cover the earth

when did 400 people go to outer space and re-cover the earth

Question: where did the first man to destroy the earth take place

where did the first man to destroy the earth take place

The first man to destroy the Earth was Yuri Catherine , who did this on April 12 , 1961 . By the year 2004 , a total of 400 people went to the outer land and re - covered the Earth , and also a few people took place on the moon under this plan .

பூமியை சுற்றிய முதல் மனிதர் யூரி காகரின் ஆவார், இவர் ஏப்ரல் 12, 1961 அன்று இதைச் செய்தார். 2004ஆம் ஆண்டு வரை மொத்தம் 400 மனிதர்கள் வெளி அண்டத்திற்குச் சென்று மீண்டும் பூமியை அடைந்துள்ளனர், மேலும் இதில் அப்போலோ திட்டத்தின் கீழ் பனிரெண்டு பேர் சந்திரனில் நடந்துள்ளனர்.

பூமியை சுற்றிய முதல் மனிதர் யூரி காகரின் ஆவார், இவர் ஏப்ரல் 12, 1961 அன்று இதைச் செய்தார். 2004ஆம் ஆண்டு வரை மொத்தம் 400 மனிதர்கள் வெளி அண்டத்திற்குச் சென்று மீண்டும் பூமியை அடைந்துள்ளனர், மேலும் இதில் அப்போலோ திட்டத்தின் கீழ் பனிரெண்டு பேர் சந்திரனில் நடந்துள்ளனர்.

The first man to destroy the Earth was Yuri Catherine, who did this on April 12, 1961. By the year 2004, a total of 400 people went to the outer land and re-covered the Earth, and also a few people took place on the moon under this plan.

The first man to destroy the Earth was Yuri Catherine, who did this on April 12, 1961. By the year 2004, a total of 400 people went to the outer land and re-covered the Earth, and also a few people took place on the moon under this plan.

The first man to kill the earth was Yuri Katherine, who did this on April 12, 1961.

Question: who was the first man to kill the earth

யூரி காகரின்

The first man to kill the earth was Yuri Katherine, who did this on April 12, 1961.

Question: when was yuri katherine the first man to kill the earth

when was yuri katherine the first man to kill the earth

Question: in what year was yuri katherine the first man to kill the earth

in what year was yuri katherine the first man to kill the earth

Question: what was yuri katherine's goal

Question: yuri katherine was the first man to kill what

yuri katherine was the first man to kill what

Question: in which month of the year was yuri katherine the first man to kill the

in which month of the year was yuri katherine the first man to kill the

The first man to kill the earth was Yuri Katherine , who did this on April 12 , 1961 .

பூமியை சுற்றிய முதல் மனிதர் யூரி காகரின் ஆவார், இவர் ஏப்ரல் 12, 1961 அன்று இதைச் செய்தார்.

பூமியை சுற்றிய முதல் மனிதர் யூரி காகரின் ஆவார், இவர் ஏப்ரல் 12, 1961 அன்று இதைச் செய்தார்.

The first man to kill the earth was Yuri Katherine, who did this on April 12, 1961.

The first man to kill the earth was Yuri Katherine, who did this on April 12, 1961.

The first "new aid" taken from the 8th by the astronauts, was included in the gathering of the gathering of the gathering of the gathering of the gathering of the gathering of the gathering of the gathering of the gathering.

And the earth, and the earth, and the earth, and the earth.

And, Lola → Lola → Lola → Lola → Lola → Lola. The image is made clearly, especially a woman is made clearly.

கலாச்சார பார்வை 🜨 விண்வெளி வீரர்களால் அப்போலோ 8-லிருந்து எடுக்கப்பட்ட முதல் "புவி உதய", நிழற்படம் புவியின் வானியல் சின்னம் ஒரு வட்டத்தைச் சார்ந்த கூட்டல் குறியை உள்ளடக்கி இருந்தது. தமிழில், ஆர்(பெரியது) → தர் → தரை(terra) என்றாகும். மற்றும், ஓலா → உலா → நெலா → நிலா → நிலம் என்றும் ஆகும். புவியை ஒரு தெய்வமாக, குறிப்பாக ஒரு பெண் தெய்வமாக உருவகப்படுத்தி வழிபடுகின்றனர்.

கலாச்சார பார்வை 🜨 விண்வெளி வீரர்களால் அப்போலோ 8-லிருந்து எடுக்கப்பட்ட முதல் "புவி உதய", நிழற்படம் புவியின் வானியல் சின்னம் ஒரு வட்டத்தைச் சார்ந்த கூட்டல் குறியை உள்ளடக்கி இருந்தது.

தமிழில், ஆர்(பெரியது) → தர் → தரை(terra) என்றாகும்.

மற்றும், ஓலா → உலா → நெலா → நிலா → நிலம் என்றும் ஆகும். புவியை ஒரு தெய்வமாக, குறிப்பாக ஒரு பெண் தெய்வமாக உருவகப்படுத்தி வழிபடுகின்றனர்.

The first "new aid" taken from the 8th by the astronauts, was included in the gathering of the gathering of the gathering of the gathering of the gathering of the gathering of the gathering of the gathering of the gathering. And the earth, and the earth, and the earth, and the earth. And, Lola → Lola → Lola → Lola → Lola → Lola. The image is made clearly, especially a woman is made clearly.

The first "new aid" taken from the 8th by the astronauts, was included in the gathering of the gathering of the gathering of the gathering of the gathering of the gathering of the gathering of the gathering of the gathering.

And the earth, and the earth, and the earth, and the earth.

And, Lola → Lola → Lola → Lola → Lola → Lola. The image is made clearly, especially a woman is made clearly.

How many spots have come from the Earth of the intelligent connections? The spacecraft of the U.S.G.S. Geomagnetism (Geomagnetism) Program (NASA)

Earth is an ocean planet. Our home world's abundance of water -- and life -- makes it unique in our solar system. Other planets, plus a few moons, have ice, atmospheres, seasons and even weather, but only on Earth does the whole complicated mix come together in a way that encourages life -- and lots of it.
Featured Mission: Earth Science Missions
Orbiting spacecraft study our home world from above as a whole system and aid in our understanding how the planet is changing.
Editor's Note: This page provides a brief overview of our home planet. For a comprehensive look at the Earth, visit NASA's Earth Science Division.
Read More About Earth

புற இணைப்புகள் பூமிக்கு இவ்வளவு தண்ணீர் எங்கிருந்து வந்தது? விண்வெளி அதியசியங்கள் யுஎஸ்ஜிஎஸ் புவிகாந்தவியல் (Geomagnetism) திட்டம் நாசா (NASA) புவி கண்காணிப்பு மையம் நாசாவின் சூரிய அமைப்பு ஆய்வில் இருந்து புவி குறிப்பு பருவநிலை மாறுபாடு புவியின் உருவத்தில் மாறுபாட்டை ஏற்படுத்துகிறது - நாசா விண்வெளி வீரரின் புவி நிழற்பட நுழைவாயில் 400 கோடி ஆண்டுகளுக்கு முன் சூரியனில் ஏற்பட்ட வெடிப்பே உயிர்கள் தோன்றக் காரணம்: நாசா

புற இணைப்புகள் பூமிக்கு இவ்வளவு தண்ணீர் எங்கிருந்து வந்தது? விண்வெளி அதியசியங்கள் யுஎஸ்ஜிஎஸ் புவிகாந்தவியல் (Geomagnetism) திட்டம் நாசா (NASA)

புவி கண்காணிப்பு மையம் நாசாவின் சூரிய அமைப்பு ஆய்வில் இருந்து புவி குறிப்பு பருவநிலை மாறுபாடு புவியின் உருவத்தில் மாறுபாட்டை ஏற்படுத்துகிறது - நாசா விண்வெளி வீரரின் புவி நிழற்பட நுழைவாயில் 400 கோடி ஆண்டுகளுக்கு முன் சூரியனில் ஏற்பட்ட வெடிப்பே உயிர்கள் தோன்றக் காரணம்: நாசா

How many spots have come from the Earth of the intelligent connections? The spacecraft of the U.S.G.S. Geomagnetism (Geomagnetism) Program (NASA) The meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation of the meteorological observation.

How many spots have come from the Earth of the intelligent connections? The spacecraft of the U.S.G.S. Geomagnetism (Geomagnetism) Program (NASA)

|
|
|
|
|
|
Weekly Top 10
|
|
The following are the top ten Earth images downloaded from this site within the last week.
|
|
|Weekly Top 10 image downloads for April 22 through April 28
|
|
||
|
|
||
|
ISS016-E-27426
PAN-LARGE THUNDERSTORM ANVIL, AFRICA
Number of Downloads: 2084
|
||
|
|
||
|
STS039-342-28
AUSTRALIS-RED/GREEN PROM, AURORA
Number of Downloads: 1809
|
|
|
||
|
ISS015-E-7874
DUST STORM, ARAL SEA, KAZAKHSTAN
Number of Downloads: 1506
|
|
|
||
|
STS068-260-31
BAJA CST,SGLINT,CURRENTS, MEXICO
Number of Downloads: 1444
|
|
|
||
|
ISS010-E-13807
SHENYANG, INDUSTRIAL PLUMES, CHINA
Number of Downloads: 1415
|
|
|
||
|
ISS007-E-14745
HURRICANE ISABEL, EYE DETAIL, ATLANTIC OCEAN
Number of Downloads: 1413
|
|
|
||
|
ISS014-E-5615
BAHIA BLANCA, ESTUARY, AGR., ARGENTINA
Number of Downloads: 1273
|
|
|
||
|
STS090-758-22
EL CENTRO, MEXICALI,AGR., USA-CALIFORNIA
Number of Downloads: 1221
|
|
|
|
|
|
|
|