what is on the top of mount everest
Mount Everest The routes usually share one spot in common, the summit itself. The summit of Everest has been described as "the size of a dining room table".[269] The summit is capped with snow over ice over rock, and the layer of snow varies from year to year.[270] The rock summit is made of Ordovician limestone and is a low-grade metamorphic rock according to Montana State University.[271] (see survey section for more on its height and about the Everest rock summit)
Mount Everest One of the issues facing climbers is the frequent presence of high-speed winds.[76] The peak of Mount Everest extends into the upper troposphere and penetrates the stratosphere,[77] which can expose it to the fast and freezing winds of the jet stream.[78] In February 2004 a wind speed of 280 km/h (175 mph) was recorded at the summit and winds over 160 km/h (100 mph) are common.[76] These winds can blow climbers off Everest. Climbers typically aim for a 7- to 10-day window in the spring and fall when the Asian monsoon season is either starting up or ending and the winds are lighter. The air pressure at the summit is about one-third what it is at sea level, and by Bernoulli's principle, the winds can lower the pressure further, causing an additional 14 percent reduction in oxygen to climbers.[78] The reduction in oxygen availability comes from the reduced overall pressure, not a reduction in the ratio of oxygen to other gases.[79]
Paris Peace Accords
Himalayas During the Upper Cretaceous, about 70 million years ago, the north-moving Indo-Australian Plate (which has subsequently broken into the Indian Plate and the Australian Plate[10]) was moving at about 15Â cm per year. About 50 million years ago this fast moving Indo-Australian Plate had completely closed the Tethys Ocean, the existence of which has been determined by sedimentary rocks settled on the ocean floor and the volcanoes that fringed its edges. Since both plates were composed of low density continental crust, they were thrust faulted and folded into mountain ranges rather than subducting into the mantle along an oceanic trench.[9] An often-cited fact used to illustrate this process is that the summit of Mount Everest is made of marine limestone from this ancient ocean.[11]