Mount Everest
 The summit pyramid of Everest | |
| Elevation | 8,848.86 m (29,031.7 ft) |
|---|---|
| Range | Mahalangur Himal, Himalayas |
| Location | Nepal / China (Tibet) border |
| First ascent | 29 May 1953, Edmund Hillary and Tenzing Norgay |
| Local names | Sagarmāthā (Nepali), Chomolungma (Tibetan) |
Mount Everest is the highest mountain on Earth measured from sea level, at 8,848.86 metres. It lies in the Mahalangur Himal on the border between Nepal and the Tibet Autonomous Region of China.
Height
[edit]Everest was identified as the world's highest peak by the Great Trigonometrical Survey of India, which in 1856 announced a height of 29,002 feet for the summit then designated Peak XV. It was named after George Everest, a former Surveyor General, over his own objection that the mountain already had local names.
The current official figure, 8,848.86 m, was announced jointly by Nepal and China in December 2020, after surveys from both sides using satellite positioning and ground-penetrating radar to separate rock height from snow depth. The mountain is still rising by roughly 4 mm a year as the Indian plate drives into Eurasia, and earthquakes can shift it: the 2015 Nepal earthquake moved the summit several centimetres.
Everest is the highest above sea level, but not by every measure. Measured from base to summit, Mauna Kea in Hawaii is taller. Measured from the centre of the Earth, the equatorial bulge puts Chimborazo in Ecuador farther out.
Climate
[edit]Conditions on the upper mountain are hostile in ways that are mostly about air pressure. At the summit, atmospheric pressure is about a third of that at sea level, so each breath delivers roughly a third of the oxygen. Above about 8,000 m — the death zone — the body cannot acclimatise and deteriorates continuously; without supplementary oxygen, most people can survive there for hours, not days.
Winter winds on the summit routinely exceed 160 km/h as the jet stream touches the peak, and temperatures fall below −35 °C. The narrow calm before and after the summer monsoon produces the short climbing seasons in May and, less often, September.
Climbing history
[edit]British expeditions approached from Tibet in the 1920s. George Mallory and Andrew Irvine disappeared high on the north-east ridge on 8 June 1924; Mallory's body was found in 1999, and whether either reached the summit remains unknown.
The first confirmed ascent was on 29 May 1953, by Edmund Hillary, a New Zealand beekeeper, and Tenzing Norgay, a Nepali-Indian Sherpa, on a British expedition led by John Hunt. They ascended the South Col route, surmounting the rock step near the summit later called the Hillary Step.
Later firsts include Reinhold Messner and Peter Habeler's ascent without supplementary oxygen in 1978, widely held to be impossible before it was done, and Messner's solo ascent in 1980.
Commercial climbing
[edit]Guided commercial expeditions from the 1990s changed the character of the mountain. Several hundred people now reach the summit in a typical season, at a cost commonly upwards of 45,000 US dollars per client. Queues form at the fixed ropes on summit day, and delays in the death zone are themselves dangerous. Around 340 people have died on Everest; the deadliest single days have come from an avalanche at Base Camp during the 2015 earthquake and an icefall in 2014, both of which killed Sherpa staff disproportionately.
The Sherpa people carry most of the risk on the mountain: fixing ropes, ferrying loads through the Khumbu Icefall, and making repeated trips through the most dangerous ground. Waste, abandoned equipment and human remains at high camps have prompted deposit schemes and clean-up expeditions from both the Nepali and Chinese sides.