A little bit of Yellowstone earthquake perspective

Old Faithful geyser at Yellowstone National Park.

A few thoughts about faulting, earthquakes and eruptions:

The earthquakes at Yellowstone have been universally attributed to fault movement rather than magmatic activity by the USGS and the researchers at the University of Utah. This is likely based on the moment solutions for the earthquakes (i.e., the sense of motion on the earthquake - side to side, dilation, etc.) and the fact that there are no directly correlative volcanic/magmatic symptoms to go with them (such as pronounced, short-term bulging, excessive hydrothermal venting, etc.) Now, a lot of you are concerned that maybe we're all misreading this and the earthquakes are being seen as merely tectonic because magma is moving things around down there.

Well, it is a little bit of a chicken-and-egg scenario: do fault move because of magmatic activity or is magma movement facilitated by fault movement. There is likely a little of both can could happen - an earthquake can trigger an eruption if the system is posed at the brink of an eruption and conversely, as we know, magmatic movement can trigger earthquakes because the crust has to accommodate the new material (it has to "make room"). So, how can we be sure that this isn't happening at Yellowstone - and remember, for extreme conclusions (like an impending eruption) we need exceptional evidence. (And take note, I'm not seismologist or structural geologist, so feel free to point out where I might be off in these descriptions).

(1) The moment tensor/focal mechanism solutions for these earthquakes are dominantly strike-slip - i.e., the "beach ball" symbol suggests the movement is side-to-side motion with some extension on the fault - or a transtensional movement with both some extension and shear. This sort of movement can be accomplished without magma just from movement along faults due to extension. However, before you get too excited ...

(2) The earthquakes are in the middle of an area of historical seismic activity that don't produce volcano eruptions. The previous activity is the best sign for what is to come is what typically happens. So, the fact that most earthquakes in this area, at that depth with this solution are tectonic rather than magmatic, it would indicate that the current swarm is saying the same thing. It is sort of like watching a guy who only hits singles but hit a home run years ago come up to bat and expect him to hit a home run merely because he's at bat. The earthquakes are commonplace at Yellowstone - just a normal at bat for the caldera.

(3) If this were, by some chance, to be magmatically related, we would expect to see a progressive shallowing of the earthquakes as the magma moved upwards (if we're worried about an eruption). So far, I have not seen either in the current swam. Even the most recent earthquakes are still at ~9-11 km / 5.6-6.8 mile depth. If you're worried about an eruption, you'd need the earthquakes to start progressing upwards - without it, it could be lateral movement of magma, or just microfaults adjusting at depth.

(4) Finally, although we have accessory anecdotal evidence of changes in the hydrothermal/magmatic system (e.g., Old Faithful isn't so faithful, the long-lived bulging under Yellowstone Lake, etc.), these correlations do not automatically lead to causation. The caldera system is very complex, so much so that events on one side of the caldera can likely be wholly unrelated to one on the other. Just because we might see signs of change in the active systems roughly correlated with an earthquake swarm doesn't mean that they must be related. However, it is a good idea to continue look for changes that could end up pointing towards a magmatic causation ... with enough evidence.

So, that is my take on this swarm and why we don't need to be panicked or concerned that things are being misread. There are very clear signs that scientists look for when dealing with earthquakes and their sources, especially when magma is involved.

More like this

With all the talk of the current Yellowstone earthquake swarm, I thought it would worth it to write a post on the the structure and caldera - and why we get earthquake swarms that are structurally rather than magmatically-related. First off, lets think about why calderas formed. This is relatively…
Steaming, gurgling mudpots in the active hydrothermal system of Yellowstone. For those of you following Yellowstone (I think there might be a few of you), I've plotted up the earthquakes since 1/27 (see below) - and sure enough, although there is a lot of scatter, they are getting shallower -…
You'll have to excuse the curtness of this post. An bad hop in softball will do that to you. Here's some news:Mt. Dempo in Indonesia Xinhua offers some nice pictures of the current activity going on at the summit crater at Nyiragongo in the Congo. Note the partially-crusted-over lava lake in the…

good that you emphasized that correlation does not equal causation. This is a major point of misunderstanding among the general public(including***sigh**educators) and is a major source of the terrible "folk" interpretations we see people make about so many issues.

You have to admit tho that ANY seismic activity above an area with multiple caldera events and a known magma body could be viewed as being influenced by the pressure on that body.

Its rather like a shattered window pane. Is the glass creaking at a fault because the house is settling (tectonic) or because the wind is blowing (magmatic) or maybe both?

Interesting that its slip-strike tho. Its good to remember that Yellowstone feels the same pressure and stress from crustal movement as the rest of the continent, but is more likely to give due to its shattered makeup.

Fitz - I guess the difference I see is "caldera-related" versus "magma-related". Yes, pretty much anything around Yellowstone is "caldera-related", but is it directly associated with magma? Not necessarily. The tectonic faulting might be indirectly related to hydrostatic (referring to any fluid, magma or water) state of the rock in the caldera, but have nothing to directly do with something "going on" in the chamber. I see your point, though.

And I forgot to thank EKoh for some earlier discussion of focal mechanisms - thanks!

Good job Erik. While surely we cannot totally exclude that somethin's cookin' at Yellowstone and eventually might lead to an eruptive event (most likely rather small-scale), I think we should dedicate our attention to things that are likely to happen in our lives, quite a large proportion of which mean trouble. The "super-eruption" scenario is intriguing and spectacular, and possibly it would be satisfying to see for a volcanologist if we lived on the moon having a direct view on Earth. But there are so many burning issues affecting our lives every day that in the end the "super-eruption" thing should play just the role it deserves - some preventive administrative planning and public awareness, but no cause for serious concern.
If it comes to being worried about a potentially disastrous eruption in a caldera system, I'd put Campi Flegrei near Naples in Italy on the high-priority list, though currently it is relatively quiet. Awareness and preparedness levels in that area are hilariously low. Yellowstone, especially to U.S. citizens, is certainly touching a sensitive spot because it lies in the heart of the country, a little bit like 9/11, it's something happening at home, not in some remote, underdeveloped country. While this is plainly understandable, probably the next bad thing to happen in the U.S. will be something nobody thinks of in this moment ... hopefully not, but that's what the past is teaching us.

Erik. Thank you for your timing on this post. I was just looking for something like this last night on the YVO site. I am doubly pleased that it was you who took the time to give your opinion of the swarms and what scientists are looking at.

"Post hoc ergo propter hoc," which is Latin for:
"After this, therefore because of this."
A fallacy of reasoning dealing with causality.

The eruption occured after an earthquake, therfore, earthquakes cause eruptions... Not!


One thing that struck me reading your post is the very anthropocentric view we all have of most everything, including eruptions. It's almost like we have to totally invert our perspective away from the surface and think our way into the depths, like we would exploring the deep ocean.

Aside from that little philosophical excursion, a more practical question that I raised the other day is what kind of signal would stoping generate as a magma body ascended? Would it look like a normal fault-related earthquake? Would it register on a seismogram? On a similar note, when we see long-period tremor, what exactly is generating it? Is it resonance from ground water getting turned to steam under pressure or magma actually "moving" (which I doubt as it is so slow) or what exactly? Obviously it is an expression of kinetic energy, but what is doing the moving?

By bruce stout (not verified) on 27 Jan 2010 #permalink

It seesm that KVERT is dead. As we all know the Kamaceken area of Russia has alot of volcanoes and the goverment in Russia could care less. This is a real shae for those interested in volancoes as well as the pilots who fly in that area,and there are alot of them. Notihng will be coming form that area any more.


Dear colleagues!


Specifically, the following KVERT services are suspended:
- Assignment of Aviation Color Codes;
- Sending:
- KVERT Information Releases about current activity and forecasts activity of
volcanoes of Kamchatka and Northern Kuriles from IVS FED RAS


Access to the following information will cease:
- KVERT information releases
- Current Activity of the Volcanoes
- MODIS and NOAA satellite images
- Weekly information on current eruptions on the IVS website

Dr. Olga Girina, KVERT, IVS FED RAS
E-mail: girina@kscnet.ru
Tel. (41522) 58627

Sergey Senyukov, KVERT, KB GS RAS
E-mail: ssl@emsd.ru
Tel. (41522) 59523


By Chance Metz (not verified) on 27 Jan 2010 #permalink

The loss of KVERT as a key player in regional/hemispheric volcano monitoring *cannot be overstated* for the following reasons: activity density, critical latitude for adverse aviation and regional/seasonal climate effects, and potential for adverse environmental/human health impact to a substantial portion of the global population by cumulative/ongoing volcanic eruption of gases and dust.

Loss of KVERT participation could NOT come at a worse time, given suspected factors at play behind the sudden uptick in global geological (earthquake) and volcanic eruption and SO2 gas release.

We respectfully request the Russian Federal Government to reconsider funding cuts to KVERT.

1) The depth averages 4-7 miles. This small one was .5km. You accidently used to 14-16 km figure of the proximity from Yellowstone Park.

MAP1.1 2010/01/22 06:01:26 44.535-110.981 ((((((0.5 DEPTH)))) 17 km ( 11 mi) SE of West Yellowstone, MT

2) Yes, there hasn't been harmonic tremor...but....

3) The earthquakes are on the edge of the caldera. That's troubling to me. It is exactly on the other side of the caldera from the swarm of 2008-2009, over yellowstone lake (which experiences uplift).

I would say that if this persists, and if another swarm begins on the edge of the caldera in another place, we need to start examining this much more closely

Wha needs to happen is all the scnetists get together and tell them that they do not advice the complete shutdown of KVERt as it will afect everyone on earth in some way. Only then will they even bother to lsiten. I hope that they they change their minds but I also know that is unlikely.


The loss of KVERT has a bigger potential for disaster in the short term than Yellowstone, as the Kanchatkan/Kurile volcanoes are directly upwind of one of the world's most important air corridors. Diffuse high altitude plumes are difficult for aircrew to detect (especially at night) and the area is distinctly short of airfields capable of taking a jumbo jet with total engine failure. In USSR days Kamchatka was regarded as strategically important, now it seems to be viewed as the vermiform appendix of Russia's landmass. Let's hope this decision doesn't lead to volcanological appendicitis

Re Yellowstone; Boris beat me to it really. Yellowstone isn't the only candidate for a major ignimbrite event, after all. Not that one's necesssarily likely, but there are plenty of virtually unmonitored calderas -and potential calderas- in Central America, the Andes, and the SW Pacific at least.

Iamgine you hear in the news about a plan crash in that area and they find out it is due to volcanic ash. Poeple will ask how could this have happened and when they find out no one is mointoring volcanic activity becuase the only people who did had their funding cut people will be very upset and blame the Russian goverment for it which they rightfully should.


Wonder what the good folk of Petropavlovsk feel about this? AFAIK it's the only city of any size potentially at volcanic risk in the area.

It is sad news about KVERT. I guess they just don't realize how important it is to watch that area and give out the aviation codes. Unfortunatley, it will probably take a crash due to an eruption to get their attention. It is almost like an intersection; traffic lights don't get put up until somebody gets killed.

As for the explaination of Yellowstone, I will have to read it again to get the gist. :-) Thanks, Erik, for taking the time to explain some of this stuff.

I have a basic question here: Can anyone recommend a good book on volcanism for an armchair explorer like me? I want to learn more. Thanks.

BTW, there were a few more quakes in the area of Mammoth and the Salton Sea when I checked.

As for calderas, there is one in N CA that hardly anyone mentions and that is Medicine Lake. There has been some mention of it lately as a potential problem waiting to happen. Not much activity up there, though. I wonder if there are more calderas than what we know about. Medicine Lake is one I didn't know about until recently.

How about the Sutter Buttes? Or Mt. Diablo? Anybody know anything about the possibility of them coming alive? I doubt it. But they are there. CA is riddled with faults and volcanoes. Wonderful.

It is just plain stupid when you have to have a disaster to realize you need smomething like volcano monitoring. People never learn do they?


@Chance Metz, you'er right! It is stupid. I remember one intersection that was one road coming to another for a three-way and at first there were stop signs. Still there were wrecks. Then the flashing red light was put in. Still there were people killed in that interesection. Now there is a stop light. It may not save everybody, but there are fewer wrecks there.

Sometimes people are just plain dumb! We have all done dumb things. I know I have. I just wish KVERT wasn't shut down. It is really critical for those who study volcanoes to know what it going on there and also for the pilots. Oh well...

In my opinion i think that we may have a single reason for this kind of swarms. As we are talking about an Hydrothermal/magmatic system we should think that stress changes are related to a deep source of CO2 degassing, maybe a batch of magma is deeper enough to not be directly located on its movement, but for sure any kind of degassing should be noticed as quakes. Of course, iÂ´m talking with no knowledge about the dynamics of yellowstone, but if you have an hydrothermal system, just a small input of gas should develope bubbles in the water table, and thatÂ´s enough to produce stress changes. The chicken-and-egg scenario is in my opinion a very good sample of what we may have here.

But in this case, even if the source of the swarm is not a pure volcanic signal, magmatic gas, magmatic degassing processes can be the driving force of this situation. A kinf od chicken-and-also-egg-at-the-same-time scenario,XD.

Congrats erik for your post!

By David Calvo (not verified) on 27 Jan 2010 #permalink

Guess they wll have to find that out the hard way.


@Chance, yes, it seems that way. I hope that it won't happen that way.

@David, Mammoth is releasing a lot of CO2 in different places and I am not sure if the quakes there are related to that or not, but one of the things the geologists are thinking is the possibility of a large reservoir of CO2 under the mountain somewhere. I know there is a lot of CO2 being released from the ground and there are areas in the Horseshoe Lake kill area that has small depressions they refer to as collapse pits and the gas collects there. There are warnings about that, too. I am wondering if the same kind of thing could be at Yellowstone. Mammoth is on the edge of the Long Valley caldera and a volcano in it's own right. The swarm in Yellowstone is on the edge of the caldera.

I am not a geologist so I have no idea if there could be a CO2 reservoir in Yellowstone. It is just an idea that there might be. As for Mammoth, they are not sure about that, either, and are researching the idea.

Erik, Boris, any comment?

Thanks for this blog, Erik. I love it.

@Diana, iÂ´ve read about Mammoth many times, and also other places baeing involved in big degassing processes. The bradiseismic events at Campii Flegrei seemed to be related to giant outbursts of CO2, but no volcanic eruption came after that. As far as you have a mantle plume at Yellowstone you have an impressive supply of CO2. There are come very good papers about this issue regarding Yellowstone.
Lowenstern et al.
"Monitoring super-volcanoes: geophysical and geochemical signals at Yellowstone and other large caldera systems" is a very good writing about the lack of evidence and familiarity with processes related to such a big structures as Yellowstone and Long Valley.

We still have a lot to learn from the signals that the guys out there are gathering.



After these quake swarms it seems like all these people are trying to tell us not to worry and this is perfectly normal. That is exactly what we want to hear, so we can look the other way and go back to sleep. However, any activity at the worlds largest super-volcano should be taken very seriously. If we all keep saying, "oh, that's normal, nothing to worry about", we may be shooting ourself's in foot, by ignoring the obvious. Yes, nothing could happen, but just as equal, something very well could happen in the years to come. NOBODY, should have the right to tell people whether or not to be alarmed, because nobody really knows. In reality, it is a 50/50 chance it will happen during our lifetime. Nuff said.

Good point we don't really know why volcanoes even erupt so there is always a outside chance that somethinng big could happen.


What I don't understand is how so many people can see Yellowstone as separate from what is happening elsewhere. The 7.0 in Haiti was two days after the 6.5 of Northern California and followed three days later by a 4.0 in Oklahoma which was followed two days later by the beginning of this swarm. Earth is a single geologic system and what happens anywhere affects what is happening elsewhere. Let's try to keep things in perspective.

I have resigned myself to the probability that I wont get to see a Yellowstone, or likely any other super-volcanic eruption. And it looks like the YS hotspot isnt going to track over my state, either. Guess I'll have to settle for whatever dismal future the next 50 yrs brings.

I am intrigued by the cause of volcanics in general. Seems to me most of the "Ring of Fire" volcanoes are directly related to water leeching up from subducted ocean crust. Yellowstone doesnt fit this style. It seems more like a mere heat-sink outlet. Theres still degassing, but just what comes out of the rock that melts as it drifts over the hotspot. Theres also rift style volcanics, where usually granite just fills in the cracks and low spots.

Is that too over-simplified?

@ David and others who are worried. Seriously, you can trust the experts. What both Erik and Boris have said is spot on. Firstly these quakes are not magma-related. You can see this in the kind of seismic signal they generate. And even if they were:
a. The chance of something getting to the surface is minimal
b. If magma nevertheless got to the surface the highest probability is a tiny eruption and the lowest probability is a super-eruption.

Sure a super-eruption is possible but it's less likely than you getting hit by lightning.


@ David Calvo. Thanks for that! The power of bubbles! Makes a lot of sense. At what depth would CO2 exsolve in this way?


@Nate: Firstly, Yellowstone is NOT the largest "supervolcano" on Earth. Secondly, it is far from being the most densely populated - that one we have here in Italy (Campi Flegrei near Naples), with approximately 3 million people living practically within it, so it's rather them who might have a tremendously good reason to be concerned. Plus, Campi Flegrei has experienced two serious seismic crises, which were also accompanied by significant ground uplift and dramatic increase in hydrothermal activity (nothing similar is occurring at Yellowstone), in the early 1970s and mid 1980s. Well, the end of the story is that it has NOT erupted (so far) and gone back to sleep (for now).

True, everybody has the right to be concerned, but I personally find it a bit of a waste of time and energy to worry about things that have one-millionth of a chance of happening compared to the probability of breaking our skulls during a simple fall at home, which, after all, is the most dangerous place we can be. I'd propose you rather play in the lottery, chances of winning millions are considerably greater than seeing Yellowstone erupt on a large scale.

First I apologize for the intrusion here. I am not a scientist, geologist, or volcano expert. I'm just a guy who is fascinated with all of this .

I have been reading posts online for the last 2 weeks regarding the whole earthquake swarm and since then have been trying get a better understanding as to why this is happening. Some articles state that this type of event is perfectly normal and not to worry while others try to scare you. Although I am not in a state of panic, I am rather curious. I can't find anywhere online about YS earthquake history. The information I have found online talks about a swarm back in 2004. Then there has been two more swarms both in starting in late December of 2008 and late December 2009. I have read all the posts above and no one really seems to truly know when a volcano will erupt. Scientist and geologists have come to the conclusion that this volcano has a history of timing from what I gather. So here is my (hopefully not ridiculous) question,...

Is it possible that gravity could have something to do with earthquakes or a volcano eruption? More so could it be a gravitational pull that is not from Earth? I only ask because I found it strange that the last two recent earthquake swarms starting to happened around the same time in December. I'm not talking about a galactic alignment, but maybe something different like an Earth wobble, moon distance, other planet being close, etc.

@Bas: Yellowstone has a long history of seismic activity, and since it is instrumentally monitored it shows ground deformation (uplift alternating with subsidence) and seismic swarms. To my knowledge, the strongest (recorded) seismic swarm to date was in 1985. That one was definitely more intense than the one in late-2008 to early-2009, and possibly similar to the current one.

In most cases of seismic and volcanic activity I am convinced that the triggers are endogenous, though gravitational pull of the moon or similar might accelerate things a bit if a fault is on the verge of rupturing or a volcano is just about ready to erupt. In any case, all "predictions" or "forecasts" of volcanic or seismic events based on planetary constellations, weather conditions, statistics and other rather theoretical assumptions have failed so far. The principal driving force is endogenous, it's within the Earth, and down there everything is extremely complicated and erratic, and thus far from being regular and easily predictable.

Here, Here, Boris! Right on!

I do know that seizmologists are studying the relationship of quakes starting other quakes in other parts of the world. A number of things have to be in place for that to happen. The wave forms have to hit just right and the area affected has to be ready to go also. One seizmologist told me (and I relayed this before) that one hour after the 7.6 Sumatran quake, Mammoth got a mini swarm. He said the timing was good because they were going to have a seminar on that very thing, quakes triggering quakes from large distances. It can happen, but not very often. And the seeming correlation between the quake in CA, Oaklahoma, New Mexico, and Haiti is just that...a correlation. CORRELATION is not to be taken as CAUSATION! Fact is, none of those quakes had anything to do with the others. The CA quake was on the southern end of the San Juan De Fucca plate and the Haiti quake was the result of the Carribean Plate moving. I don't know how, right now, the San Juan plate moves in relation to the Pacific Plate or which subducts the other, etc, but it seems to me that the Carribean Plate moves east, as it did during the 1976 Guatemalen quake, and the others move north or north-west. And there are a lot of faults that are not directly related to the plates at all.

Concern is ok. Worrying about something we have no control over doesn't help one bit. The whole point is to be aware and do some kind of personal prep for any emergency that may happen. I live in a fire prone area. It is just a matter of time before we have a major fire that comes into town and every year we have a fire info day to help the people to know what they can do to help fire fighters save their homes. I also live near a fault zone. Not one likely to move any time soon, but it is there. So the thing to do is have some kind of plan to handle emergencies. That can help take the worry out of the equation.

In the mean time, I find it facinating to watch what is going on. And we can always help eachother in any situation.

I think gravity of the moon does have an effect on geologic processes here on Earth, although there's still a lot of debate on that. But if there would be an eruption or (large) earthquake that is triggered by the gravitational force of the moon, it would only be when the eruption or earthquake is about to happen anyway.

By Gijs de Reijke (not verified) on 28 Jan 2010 #permalink

Hello to all,

Situations like this are interesting to watch for obvious reasons...And some not so obvious. I've been following and monitoring Yellowstone for a year now, And it's the attitude of people that amaze me most. People seem to think that just because we occupy this planet, And thanks to modern times, Observe it...That nothing " Major " will happen. All I keep hearing is " not in our lifetime " or " It's normal activity, nothing to worry about "....Okay, Yellowstone may just be experiencing normal activity, But isn't that statement itself misleading. We've only recently been given the chance to see into and feel whats going on under there. How much " recorded " info do we really have? 20, 30, 40 years worth...At best..That amount of information for that time period is but a mere pin prick, a tiny miniscule dot. How can we know what's " normal " when we can only view the last 40 years of info on a system that has been active and living for millions of years? It would be like someone observing me for 5 minutes and then asking them to define MY normal behavior...C'mon people, be smarter...please. Given the history of the volcano and it's eruption rate aren't we being just a little overly confident? I don't trust anything SAID BY ANY of the scientist's from YVO or USGS or ANYWHERE!! Even if they felt something was going to happen they can't really say anything. They are not going to take the chance of being discredited if nothing happens, that's their lively hood and career. And not to mention the financial consequence...Imagine the hysteria if credited, trusted scientists announced Yellowstone was about to blow...Billions of $$ possibly wasted, Hundreds of thousands of people forced to vacate homes ( and where would they go? ) everything would be in chaos and then the volcano never blows...Who in their right mind would speak up and potentially be pinned with the fall out. Unless we start to see ( together at once ) uplift at fierce rates, ground temps rising quickly, major gas emissions and more frequent large quakes..to name a few things..the good people at YVO & USGS are going to remain quiet and just continue with the standard statement. Personally, I wouldn't be surprised if Yellowstone blew. Just looking at the data over the last decade is cause for concern, the uplift alone in recent years has been VERY steady, ground temps have increased to the point where some areas have been closed indefinitely, earthquake swarms coming more frequently...with stronger, shallower quakes...And I just recently read a report that states there is 20% more magma than previously thought. All I can think is ' thank goodness I live in Boston, MA ' I used to live in Helena MT...Even though the entire planet would be affected at least I'll survive a little while, as opposed to being wiped out in the initial blast and rain of ash...And that's my two cents on the matter...It's definitely an interesting time to be alive right now :-)

@Tbaby - what you say and think and believe or not is fully understandable and certainly has some logic to it. But, in the end, if you don't believe the scientists "anywhere" (which would also include me and I take that as an offence), then one must wonder why we are there at all, and why there is this Eruptions blog and all the output that comes from our work. Why do we go out and discuss with people?
If you happen to read some modern publications in volcanology you will see that we do indeed give enormous amounts of warnings in nearly every volcanic area, and for this reason we're not very popular because people won't hear them. And in spite of our warnings, people continue to develop areas that are at risk not only from volcanic eruptions but also from earthquakes and landslides and flooding and hurricanes and so on. This is why disasters happen over and over again, not because we don't have the knowledge, and not because there have been no warnings: also the latest Haiti earthquake had been publicly warned of by scientists nearly 2 years earlier. Be sure that we are not shy to voice our concerns where we think they're appropriate.
You must also consider that the people who work on Yellowstone and other dangerous volcanoes - sometimes risking their lives - cannot be compared to someone who you have met 5 minutes ago. These people first pass many years carrying out university studies and learning to interpret volcanic products and processes in the field. Then they continue to work on volcanoes, and there's intense exchange of experience and knowledge between scientists worldwide. There are fascinatingly revealing ways of reading in the history of a volcano, so that you actually get to know much more of them than what you are observing in this very moment or even in the entire historical period. Once a volcano is thoroughly studied (and be sure Yellowstone is), its entire story is unraveled with more or less precision. This is why we know much more than only the last 40 years of Yellowstone or of any other volcano.
Therefore you may rather compare us to medical doctors, of whom you also would expect to understand rather rapidly what is up with your health, thanks to their specific education and experience. Certainly even an expert cannot predict exactly your behavior in the next few minutes or hours. But you can count on one thing: we do know our stuff, as I think you do in your profession, and I think this is something you should respect and appreciate. Furthermore, much of the data now available is not "top secret" and could be analyzed by whoever has the skills to do that. Much original, real-time seismic data is rendered public by universities and other institutions. So there is no way things will be kept hidden from the public, and you can see this the way Global Warming is discussed in the public. Why on earth should that sort of information be hidden? And then, as I already said in an earlier comment, we should not lose our sight of bad things that we can be certain will happen, and they are much more frequent and much more threatening in our everyday life than in Yellowstone.
Greetings from someone who lives - rather quietly - on one of the most active volcanoes on Earth, Mount Etna in Sicily

I hear what you're saying on the small window of scientific observation of the Yellowstone system Tbaby. I keep telling people the same thing about the whole 'global warming' thing that's been going on for last few years.

Though no one has any way of knowing what the runup to a super-volcanic event would be like, we have documented and witnessed many smaller eruptions of various levels, types, and causes. I think the obvious knee-jerk attitude is that it would be like the prelude to a 'normal' volcanic event but with the signs being greatly amplifed due to the massive size of the system. Whether this is true or not is anyones guess and I agree that the system in Italy should be more concerning to everyone at this point due the population immediately around it as well as the fairly recent activity Boris mentioned.

I think the bottom line is there isn't anything anyone is ever going to be able to do about large, destructive, natural events be they by weather, earthquake or volcanism. At least we can say we can usually predict the weather a couple days ahead of time and, usually, give warning of an eruption. Earthquakes are kind of the wild card imo - they don't affect the weather, but can cause lots of other big problems(landslides, tsunamis, sometimes even volcanism). I know I don't want to see any more 9+ mag quakes in the vicinity of Toba\Anak Krakatau anytime soon.

By IndybearFan88 (not verified) on 28 Jan 2010 #permalink

@ Boris...Allow me to clarify. I don't believe anything the people at YVO or USGS say in regards to Yellowstone being a non-issue and that everything is status quo. Same for others in the scientific community, yellowstone being a non-issue...I was speaking about this specifically, not in 'general ' sorry...Also, I didn't catch your field of study...You study the science of...?

But I still disagree. There are far too many conflicting reports, articles and publications that contradict each other...The scientists and vulcanologists that study and work in Yellowstone all give the same mundane information, with little to no variance from one to the other. While else where, Like here in Boston, The people at Harvard, B.U. and MIT are having a field day with this new activity at Yellowstone. And the talk around town and at the cafeteria tables is VERY interesting...What I hear from the scientific community around here ( professors, geologists ect..) is almost the opposite of what literature and statements coming from YVO. And I'm sorry but that makes me uneasy and skeptical.

Thanks for the responses. I know that there has been many earthquakes in the past that occur on different dates. The fact that YS has been displaying more activity in late December just seemed a bit odd to me and made me think about the timing. Here is a few other earthquakes that occurred right around the same time:

December 26, 1932, China, 70000 killed
December 26, 1939 (23:57 UTC), Turkey, 35000 killed
December 26, 2003 (1:56:52 UTC), Iran, 32000 killed
December 26, 2004 (0:58:53 UTC), Indonesia, 225000 killed

Does that seem strange to anyone else? I wonder if there was activity the years prior around the same time.


Please look at comment 15 on Monday's Musings. You remind me of my Neice and that friend of mine at work.

Please, do your own research, look at all of the facts, not just the things that you want to believe.

Do you really want to live your life, all freaked out about about how the Universe or the Earth is going to destroy us next?

Life is too short to worry about something that most likely won't happen for 10,000's of years.

And Tbaby, if you had looked through this site, you would know who Dr. Boris Bencke is and how we respect him here.

Ignorance is dumb. I'm not saying we should all "worry" about it erupting tomorrow, I'm saying we should keep in mind that it CAN happen in our lifetime, and ACCEPT that. If we keep being ignorant and always think "nothing bad will happen during MY lifetime", well, then you are a very special person. People have Yellowstone's probability of erupting during their lifetime way off. Answer this: An event happens every 600,000 - 700,000 years. 640,000 years have gone by. What is the REAL probability of it happening in the next year? Well there is another 60,000 years until we reach 700,000, but wait, it erupts every 600,000-700,000 years which means it could happen any year now since we are at 640,000. The chance then? One would think very high. Swarms and other activity at Yellowstone should be paid very close attention to, yes, it probably won't happen tomorrow, and the SWARM is NOT an indication of IMMEDIATE eruption, but would we see activity increase, ground uplift, etc, a few years before eruption? Yes. Let's not get excited or "worry" now, but if activity keeps increasing over the months and years, pay attention.

@Boris Behncke, Firstly, Yellowstone is NOT the largest "supervolcano" on Earth

Oh really? I guess I should have said the "Largest ACTIVE Supervolcano on earth", because it is from what all the documentation says on it and all the geoligists. I've been studying yellowstone for 7 years, and live right next to it. I'm not saying "I know everything", like some people do on here, but I know quite a lot about Yellowstone.

@Tbaby: I have a question for you. Have any of the professors and geologists you are talking about in Boston been out in the field studying the quakes? It really is the fields geologists that know the most about what is going on. I am not bad mouthing any of the others, either. We need geologists of all the specialized fields they are in. I just wonder how much is opinion and actual experience studying the data. And if you do not trust the geologists at Yellowstone, why are you trusting the professors and geologists in Boston? All of them have their place and they all know more than those of us who are not in that field.

Having said that, there is a chance for an eruption. However, it isn't as likely as some people think. It also may not be as far away as others think. As for data, there is data from 2000 years or more. May not be from seizmographs and instruments, but the data is there. We know when a lot of quakes and eruptions happened. I saw a book that had the seizmographs from the 1906 SF quake from all over the world. That was over 100 years ago. So there has been much more info than just the last 40 years.

I live in CA. Near me are the Sutter Buttes which are volcanic and are right in the middle of northern Sacramento Valley. There is Mt. Diablo in the South Bay area. Shasta, Lassen, Medicine Lake caldera, Long Valley caldera (now there is one that had as many quakes or more in the resurgent dome area than Yellowstone is right now, and didn't erupt) Mammoth Mt. on the rim of Long Valley is another one. CA has a lot of volcanoes and fault systems that would probably make anybody wonder why we live here. Most would say the risk is worth it. Fact is, there isn't anyplace on this earth that is completely safe. Ain't no such thing.

As for Boris, here is a man that can speak several languages, has a PhD in volcanology, and knows about almost every volcano on this earth. He has been studying Etna for a long time and knows a lot about the innerworkings of that Volcano. He sees it every day.

He is right when he says that a lot of warnings have been given. Just take SF. They know a big one is coming. They just don't know when. And he is right when he talks about people being warned and not doing anything about it. Just look at New Orleans. They will probably be hit with another hurricane sometime, but they are rebuilding. Why? Because they like it there. And Boston isn't immune.

I'll get off my soap box now. I just know, since I have take geology, that they know what they are talking about and as for the differences in opinion and reading the data, to use Boris' analogy, sometimes doctors disagree on the data they are reading. That is why we get second opinions and sometimes a third. When you keep getting the same diagnosis from several different geologists, you are much closer to know what is really going on.


Keep in mind people that are experts with regular volcano's still cannot be trusted for determining the works of a supervolcano. Supervolcanoes are much different than regular volcanoes. I'm sorry if I offended anyone on here earlier, its just that I get mad when people give off assurance of what is happening, when we've never quite mastered the works of such a different volcanic system. As the geologists from YVO said via email "It's difficult to separate out tectonic from volcanic at a place like Yellowstone. Almost nothing is purely one or
another. And the hydrothermal system is also part of the earthquake- generation process. The swarm certainly could relate to release of stress from all the accumulated strain built up through the caldera uplift over the past 5 years"

No one can go around saying "this has NOTHING to do with the volcanic system at Yellowstone", because they absolutely do not know that. Again, I think both sides are wrong. The people going out saying that Yellowstone will not erupt during my lifetime, are just as wrong as the people saying it will erupt. I BELIEVE, the only correct answer is "Yellowstone CAN erupt during my lifetime, but I hope it doesn't".

Wow, some of the banter that's popped up here is amazing.

@TBaby and Nate, you both sound concerned because you want to be concerned. Believe me, every volcanologist I have read is also supremely fascinated by the mechanisms of eruptions and yes, also their potential scale. But you really must get things into relation:

Earthquake swarms are very very common in caldera systems all over the world. There are currently four sites of pretty sustained seismic activity in or near Lake Taupo. FYI Lake Taupo is generally considered to be the most productive rhyolitic system on Earth at the moment. To give you a sense of scale, Taupo has erupted 27 times in the last 26,000 years of which the first eruption was a super-eruption and a couple of others were pretty ginormous too (the last one the Hatepe eruption, 1800 years ago was VEI 7) and pretty violent. But despite this enormous output, the main point is that of those 27 eruptions, 24 were much smaller and to be honest the main risk I see there is precisely one of those small eruptions creating a seich that goes screaming down the Waikato River with all its hydroelectric dams.
So basically Taupo makes Yellowstone look positively benign. And IF there is an eruption the probability chart is that a small eruption has the highest probability and a large eruption the lowest. This is not pie in the sky. It is demonstrated daily all around the world and can be seen in the geologic record.
Also, you walking straight into the fallacy that volcanoes go off like clockwork. They don't. The mechanisms that power them are far too complicated.
Finally, have a look at the great maps of historical seismicity in that region. There is a lot of it way beyond the borders of the park that is obviously purely tectonic.
You are doing the folks at USGS and YVO a huge disservice by disparaging their motives.

By bruce stout (not verified) on 28 Jan 2010 #permalink

@bruce stout, I am not "concerned" about Yellowstone, I am actually fascinated with it. It's a place on earth that is "alive", as Bob Smith say's, "its a living, breathing caldera". I'm not one that is worried about it erupting tomorrow, but I like to pay attention to the activity there over many years of time. We haven't had any swarms like this since I've been studying Yellowstone in 2003, when the 4.4 hit Norris Basin. The 2009 Swarm and this 2010 Swarm are very interesting. Of course, we may normally see this kind of activity at Yellowstone. I guess what people need to determine, is what exactly is the threshold point where activity is "above normal" at Yellowstone? There is a saying, if you put a frog in water, and warm it slowing, it will stay in there and cook itself to death. If you warm the water rapidly, it will notice the change and jump out.

Sorry Nate, I didn't mean to lump you in with T-baby's disparaging remarks about the YVO. I am glad you are fascinated by Yellowstone. That makes you a kindred spirit for me! It's our job to try and dream up difficult questions for the experts. I've been trying for a while now (and failing miserably. Ha!)


TBaby ,
I hate to tell you, the volcanology and seismology communities are fairly small worldwide and most of the top people at Havard, MIT, BU and (BC by the way, big seismo group there) know and work with the folks at the USGS. And if you don't know who Boris is, I think its pretty safe to say you don't know what any of these people in town and a cross the river think.

Just a few thoughts regarding the comments following my previous message (#34). Firstly, I am one of quite a few volcanologists (I'd say we're a few hundred to maybe thousand worldwide) who are interested in understanding active (or potentially active) volcanic systems, and in educating people living in areas at potential risk from volcanic eruptions to better understand volcanic hazards and be prepared in case of a crisis. One of my functions is to respond, along with a small group of colleagues at the National Institute of Geophysics and Volcanology in Catania to questions of the public.

Secondly, I have to deal with many people who express similar thoughts and concerns as Tbaby - and to some degree Nate - and I must say that I find this very human and understandable but I note that there is a tendency to become extremely fixed on this particular one thing that might affect our lives negatively, and thus to fail to recognize and be prepared for a great number of other - maybe less spectacular, maybe less globally relevant, but millions of times more probable - hazards. I do not deny the possibility that Yellowstone might erupt soon. I just give it the priority it has in this moment and for the foreseeable future - it is the least likely thing to happen of all possible volcanic disasters.

@Tbaby, if you're still with us - I wouldn't like you getting shied away by some of us being a bit upset about your remarks about the credibility of the scientists. It is important that you know that discussion and, sometimes, disagreement, is among the most vital elements of the progress of science. Without questioning established hypotheses over and over again, we wouldn't have arrived where we are. And then, what people express in private in a cafeteria, is one thing. You would have your head turn if you heard some of the bickering of us who work on Etna and know that one day we will have to face a powerful and potentially very destructive eruption here. We are all fascinated by volcanoes after all, and seeing them erupt - even if sometimes destructively - is always spectacular to us, although you can count on one thing, we do not wish to see disasters happen. One of the main goals of our work is to prevent them. And one of the main vehicles of disaster prevention is providing as much information to the public as possible, as much as we understand so far - which has, indeed, a few limits.

But maybe you have heard about Pinatubo in the Philippines, which produced a very large eruption in 1991 - though far from a cataclysm that everybody has the hype about now for Yellowstone. That eruption, one hundred or even fifty years earlier, would probably have killed tens of thousands of people. Pinatubo was virtually unknown to volcanologists because it had last erupted about 650 years earlier and nobody gave it any priority. When it began to tremble and sputter in April 1991, it was rapidly seen that no geological studies had been carried out at this volcano and therefore its potential danger was unknown. In a very hasty but expert manner, geologists went into the areas surrounding the volcano to read in the records of its history - the deposits of past eruptions - and came up with the realization that this volcano, each time it erupted, it did so very violently. This is why an immense effort was made to convince tens of thousands of nearby residents - who were very reluctant to leave - that evacuation was imperative. They did finally leave - and the total death toll of Pinatubo's 1991 eruption was a few hundred, including many people who had still refused to leave their homes next to the volcano.

@Nate, I understand that you are rather fascinated by Yellowstone than worried, which is something quite positive. But it is important that also you put things into the correct perspective. I do insist, Yellowstone is NOT the largest "supervolcano" there is and it is not the largest active "supervolcano" (by the way, the term "supervolcano" is highly inappropriate because it literally means "more than a volcano", which Yellowstone is not - it's a volcano after all). Have you ever heard of Toba in Sumatra (Indonesia)? Bruce Stout (comment #43) mentioned Taupo, which is far more frequently active than Yellowstone and not smaller at all. The South American Andes boast with a number of gigantic caldera systems similar to, if not larger than, Yellowstone, which show signs of unrest (seismic activity, swelling). Then, I would consider Campi Flegrei near Naples in Italy far more dangerous because it's maybe a bit smaller than Yellowstone but home to 3.5 million people, and even a rather modest-sized eruption there would mean Armageddon.

Then, that thing with the "about 700,000 years recurrency rate" ... volcanoes are not Swiss clockworks. They are hilariously complex systems, where everything that happens depends on millions of different factors, like magma composition, supply rate, interaction with the crust, with lines of tectonic weakness, and so on. The likelihood that Yellowstone will erupt "during our lifetimes" (in a cataclysmic manner, I mean) is about as high as that it will not erupt for another million years, because volcanoes do not follow any schedules, and they don't obey to what are rules and laws to us. If you are interested in Yellowstone you should know that the last eruption there was not the last big cataclysm about 640,000 years ago, there have been dozens of smaller eruptions since then, most recently 70,000 years ago. If Yellowstone erupts soon, there is a 99.9 per cent probability that this will be another relatively small eruption - and there are not 3.5 million people living WITHIN the active volcanic system, the caldera. In any case I would place whatever bet that the next large volcanic eruption or disaster will happen someplace no one has mentioned in this entire discussion.

I just read about Campi Flegrei. You say 3.5 million live there. That could be a huge disaster with out weeks of warning.
As for Yellowstone, not worried one bit, in fact where should my family and I stay this August? I want to take them.

By Dasnowskier (not verified) on 29 Jan 2010 #permalink

Boris: just a minor addition to your comments on Pinatubo: the death toll would have been even smaller but for a horrendous bit of bad luck, in that the climax coincided with the passage of Typhoon Yunya, generating torrential rain which both made the lahars more destructive and added to the weight of ash on roofs - so the volcanologists efforts were if anything understated by the media

@Boris Behncke, just curious, I've been studying Yellowstone since 2003. I've watched / recorded every documentary, read every book, and even talk with Geologists that work in the park directly. Many times, it has been documented,when Yellowstone was revealing itself in early 2000, "Scientists have found the largest active volcanic system known to man". The park also contains 50% of the worlds geothermal features. Toba, is the only other volcano comparable to Yellowstone, and when it erupted last (only 74,000 years ago), its eruption was a little larger or equal to Yellowstone's 3rd eruption in the past, around 2.1 Million years ago. But for the current record, there are many statements by creditable sources that rank Yellowstone as the "largest active volcanic system in the world". Toba, from what I understand isn't as active (thermals, earthquakes, ground deformation, etc), that is why Yellowstone is so popular, because of its notorious count of active thermal features and earthquake swarms. This place is alive.

Hello to All from Wyoming....Wow! I, for one, am thrilled to know that knowledgeable people from around the world are watching the activity in western Wyoming and Yellowstone Park. We have lived within the Yellowstone Ecosystem for over 30 years. It is a bit frightening to learn of the possible pending diaster. So what can we really do to be prepared? Boris, you mention that you help educate the public who live in "volcanically" active areas on awarenss and preparedness. Where do we find such information? Our town of Dubois is located approximately 85 miles southeast, as the crow flies, of Yellowstone Lake. We are between the Absaroka Mountain Range to the north and the Wind River Mountains to the south. There is evidence of thermal activity right here with extinct geyser pools and warm springs. It is always good to educate oneself. These posts simply bring more knowledge to more people which is a very good thing. Please give direction as to areas of information on preparedness and especially accept our thanks for your alertness and devotion. Appreciate the discussion.

By FromWyoming (not verified) on 29 Jan 2010 #permalink

One more thing...... Our son takes interruptive, guided snowmobile tours through Yellowstone Park everyday. He calls me from Old Faithful just to say "Hi". Even though the loss of life would not be on the scale of other volcanoes should something happen in Yellowstone, the idea that education and preparedness prevented loss of life is a most justifiable and noteworthy use of one's time. Our son is working in Yellowstone everyday and we know many, many good people that live in the Yellowstone area. We can never take any lives for granted. It is so important to have discussions that led to correct thinking....it can be a bit unnerving to learn of things that directly affect one's life and not be able to do much to prevent it but with education and insight from others we can all learn and help one another. Knowledge is powerful. Please note how helpful these posts are.

By FromWyoming (not verified) on 29 Jan 2010 #permalink

@Diane: Mt. Diablo is a tectonic mountain, not a volcanic dome, so I wouldn't worry about it erupting any time soon. The Sutter Buttes are believed to be inactive (I think nothing in the last 1.3 million years or so), but they are a very cool feature nonetheless.

@FromWyoming, like Boris said, there are far other hazards that are more probable to worry about, rather than Yellowstone. Yellowstone has a low chance of erupting, and if it does, its hazard effect could be so great, why bother preparing for it? At least that is what a lot of people around here think. Me, I'd say "Be Ready 4 Whatever". I live near Yellowstone, 50 miles away. I am ready, as in heading north if any happens here, now, or many years from now. Anyone leaving right next to volcanoes should be ready to leave at anytime, regardless of the probabilities of it erupting. Its those people that say "it'll never happen to me", that find themselves in a rut hole they can't climb out. My motto, BE PREPARED.

@Big Lou: Where did you get the info about Mt. Diablo being a techtonic mountain? The info I had was that it is a saddleback volcano and that the reason it is called Diablo is because the Spanish found fumerols on the mountain when looking for sheep. I will have to dig into this one.

Diane - I know I've seen the information about the tectonic origin of Mt. Diablo at the visitors center. It is definitely an odd edifice, but pretty clearly not volcano. Not sure where those legends might come from, though.

@Erik and Big Lou,

I just did a study on MT Diablo and here is what I found. It is from the Mt. Diablo Interpretive Association and Roi Peers. Apparently the three of us are right about it. Remember, I took geology over 30 years ago and that is one of the things about Diablo they were saying and now they have found new things in the last 30 years. I think the volcanic idea came from what I am going to quote:

"Mt. Diablo Ophiolite Basalt: The basalt, which makes up the upper part of the Mt. Diablo Ophiolote, i smostly interbedded pillow basalt lava flows. As the lava erupts under water, the outer surface of the flow "freezes" in contact with the water. More lava breaks through and again the outer surface "freezes. This process leads to the accumulation of "pillow" structures and the resultant rock is referred to as pillow basalt or pillow lava. The basalt has a microscopic crystaline texture with black to greenish-brown color, weathering to a yellowish-brown to dark reddish-brown soil. Well seveloped pillows can be seen on Mitchell Rock.

Mt Diablo Diabase: The pillow lavas are fed by a series of verticle fissures ,or dikes, that allow the molten rock from below to reach the surface.The molten material in teh dikes solidifies into a rock called diabase, which has the sam chemical composition as basalt, but with a coarser texture. Diabase is exposed in quarries at Mt. Zion and on Eagle Peak."

There is also some subduction in the area, or was, so there is probably where the volcanic idea came from. Lava, basalt, volcano.

This is what I found briefly and I know there is more and, yes, it was uplifted by techtonic action and the Franciscan rock is along the San Andreas fault on the west side of the fault.

Diablo is certainly a mishmash of rock and geology. Thanks for the new info. New to me, anyway. I learn something almost every day here.

I was about to post again on probability and geologic timescale and my view of volcanism as an engineering problem, then I realized from Nates Post #54 that what we really need at this stage is some Info on How to Prepare, in case YS or any of the MANY possible volcanoes start to cover us with ash.

1) Someone from Memphis said they wouldnt go closer to YS than OKC? Not to worry, Erik can probably let us know the geographic extent of the "welded tuff" from the largest eruptions. The ash fall is cooler outside that region, and lighter the farther away you go.

2) Stock your car or truck with a box of survival goodies. This will help no matter what emergency you face if you need to travel.

3) Leave early - better to drive a day and come back looking stupid than to be stuck in traffic

4) For an eruption you need some extra items. Dust masks are better than bandanas. Extra water to clean em cuz you wont have enough. Extra air filters for your vehicle, they'll clog in minutes in heavy ash. A snow shovel, to clean your roof if you stay home or find a shelter. Ash will collapse a roof quickly if it rains.

What about the Earthquake today Jan 31. It was only one mile deep a mag 2.9 This was 25 miles East of West Yellowstone. This is a new spot away from the others and it's near one of the old vents.

What do others think about this Earthquake? Let see if this also becomes a new hot spot for new Earthquakes in the coming days. With it only one mile deep it's only 5,284 feet to the top before it come out.

Note this was only one mile deep near old vent. The others are 10 - 12 miles SE of Yellowstone

By Todd Thorn (not verified) on 31 Jan 2010 #permalink

You said, "If you're worried about an eruption, you'd need the earthquakes to start progressing upwards".

I would suggest you look at the seismic activity and DEPTH once again....it has been steadily moving upwards and just today was only 4.8 km deep with one earthquake YESTERDAY that was only 0.1 km deep.

Time to take this very seriously.


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