How High Exactly Is Mount Everest?
Mt. Everest is officially said to be 29,029 feet (8,848m) high. In a bid to end the “confusion” over its exact height, the Nepalese government is conducting its first-ever measurement of the world’s tallest mountain, says the BBC. China and Nepal dispute how exactly to measure the mountain’s height, with China saying the rock height should be measured and Nepal the snow height, based on the snow cap on the mountain. Using the snow height adds about four meters to Mt. Everest’s height.
A figure of 8,848 meters was recorded by an Indian survey in 1955. Tensing Norgay and Edmund Hillary first climbed to the summit in 1965; more than 3,000 climbers have also attempted the feat, with at least 219 dying while trying.
Geologists point out that, due to the shifting of continental plates, Mt. Everest is actually becoming higher, with India gradually pushing beneath China and Nepal. A team of Americans used GPS technology to record a height of 8,850 meters — 29,035 feet — using GPS technology in May of 1999. This figure is now used by the US National Geographic Society, but Nepal has yet officially to accept it.
According to Australian Geographic, Nepalese scientists are planning to set up reference points on Mt Everest, after which they will use GPS satellites to calculate a precise height; it’s estimated that it will take two years to measure the mountain. Paul Tregoning, a geophysicist from the Australian National University, explains how one exactly goes about measuring the world’s tallest mountain:
“Estimating the height of mountains is more difficult and complicated than it sounds. To get an updated GPS height of the top of Mt Everest, it’s conceptually very simple: you go up to the top, turn on a GPS and it will calculate a height accurate to about 1m. But in practice, someone’s got to climb the mountain carrying the equipment.”
To obtain a precise measurement involves overcoming a number of technical challenges, he says. “The first problem is that the height must be a measurement with respect to something. It must be relative to sea level, for example, or to what is called a ‘reference ellipsoid’ — a mathematical surface.
“The height that is provided by a handheld GPS is the height above this mathematical surface and is not related to sea level.” Such surfaces are used by geographers as a more accurate basis for calculating elevation.
At issue also is what is defined as the “top” of the mountain. The US team that recorded the measurement of 8,850 meters used the snow cap as the top. The Chinese Academy of Sciences and the State Bureau of Surveying and Mapping measured the rock underneath to come up with a height of 8844.43m.
Mt. Everest traverses the China-Nepal border and the two countries have had a “long-running dispute” about its proper height. In April of 2010, the two countries reached a compromise about Mt. Everest’s height “by agreeing the two measurements referred to different things — one to the height of Everest’s rock and the other to the height of its snowcap.” Depending on what the Nepalese scientists record after their investigation, it looks like the dispute could open up again.
Whether to go by the snow height or rock height seems a potentially philosophical question: Is a mountain as high as the (frozen) snow piled atop it, or only based on the rock that composes it?
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