plate teIt is thought that the plate tectonics of the area are adding to the height and moving the summit northeastwards. Two accounts suggest the rates of change are 4 mm (0.16 in) per year (upwards) and 3 to 6 mm (0.12 to 0.24 in) per year (northeastwards),[33][39] but another account mentions more lateral movement (27 mm or 1.1 in),[40] and even shrinkage has been suggested.[41]
The summit of Everest is the point at which earth's surface reaches the greatest distance above sea level. Several other mountains are sometimes claimed to be the "tallest mountains on earth". Mauna Kea in Hawaii is tallest when measured from its base;[42] it rises over 10,200 m (33,464.6 ft) when measured from its base on the mid-ocean floor, but only attains 4,205 m (13,796 ft) above sea level.
By the same measure of base to summit, Denali, in Alaska, also known as Mount McKinley, is taller than Everest as well.[42] Despite its height above sea level of only 6,190 m (20,308 ft), Denali sits atop a sloping plain with elevations from 300 to 900 m (980 to 2,950 ft), yielding a height above base in the range of 5,300 to 5,900 m (17,400 to 19,400 ft); a commonly quoted figure is 5,600 m (18,400 ft).[43][44] By comparison, reasonable base elevations for Everest range from 4,200 m (13,800 ft) on the south side to 5,200 m (17,100 ft) on the Tibetan Plateau, yielding a height above base in the range of 3,650 to 4,650 m (11,980 to 15,260 ft).[35]
The summit of Chimborazo in Ecuador is 2,168 m (7,113 ft) farther from earth's centre (6,384.4 km (3,967.1 mi)) than that of Everest (6,382.3 km (3,965.8 mi)), because the earth bulges at the equator.[45] This is despite Chimborazo having a peak 6,268 m (20,564.3 ft) above sea level versus Mount Everest's 8,848 m (29,028.9 ft).
Geologists have subdivided the rocks comprising Mount Everest into three units called formations.[46][47] Each formation is separated from the other by low-angle faults, called detachments, along which they have been thrust southward over each other. From the summit of Mount Everest to its base these rock units are the Qomolangma Formation, the North Col Formation, and the Rongbuk Formation.
The Qomolangma Formation, also known as the Jolmo Lungama Formation,[48] runs from the summit to the top of the Yellow Band, about 8,600 m (28,200 ft) above sea level. It consists of greyish to dark grey or white, parallel laminated and bedded, Ordovician limestone interlayered with subordinate beds of recrystallised dolomite with argillaceous laminae and siltstone. Gansser first reported finding microscopic fragments
The Qomolangma Formation, also known as the Jolmo Lungama Formation,[48] runs from the summit to the top of the Yellow Band, about 8,600 m (28,200 ft) above sea level. It consists of greyish to dark grey or white, parallel laminated and bedded, Ordovician limestone interlayered with subordinate beds of recrystallised dolomite with argillaceous laminae and siltstone. Gansser first reported finding microscopic fragments of crinoids in this limestone.[49][50] Later petrographic analysis of samples of the limestone from near the summit revealed them to be composed of carbonate pellets and finely fragmented remains of trilobites, crinoids, and ostracods. Other samples were so badly sheared and recrystallised that their original constituents could not be determined. A thick, white-weathering thrombolite bed that is 60 m (200 ft) thick comprises the foot of the "Third Step", and base of the summit pyramid of Everest. This bed, which crops out starting about 70 m (230 ft) below the summit of Mount Everest, consists of sediments trapped, bound, and cemented by the biofilms of micro-organisms, especially cyanobacteria, in shallow marine waters. The Qomolangma Formation is broken up by several high-angle faults that terminate at the low angle normal fault, the Qomolangma Detachment. This detachment separates it from the underlying Yellow Band. The lower five metres of the Qomolangma Formation overlying this detachment are very highly deformed.[46][47][51]
The bulk of Mount Everest, between 7,000 and 8,600 m (23,000 and 28,200 ft), consists of the North Col Formation, of which the Yellow Band forms its upper part between 8,200 to 8,600 m (26,900 to 28,200 ft). The Yellow Band consists of intercalated beds of Middle Cambrian diopside-epidote-bearing marble, which weathers a distinctive yellowish brown, and muscovite-biotite phyllite and semischist. Petrographic analysis of marble collected from about 8,300 m (27,200 ft) found it to consist as much as five percent of the ghosts of recrystallised crinoid ossicles. The upper five metres of the Yellow Band lying adjacent to the Qomolangma Detachment is badly deformed. A 5–40 cm (2.0–15.7 in) thick fault breccia separates it from the overlying Qomolangma Formation.[46][47][51]
The remainder of the North Col Formation, exposed between 7,000 to 8,200 m (23,000 to 26,900 ft) on Mount Everest, consists of interlayered and deformed schist, phyllite, and minor marble. Between 7,600 and 8,200 m (24,900 and 26,900 ft), the North Col Formation consists chiefly of biotite-quartz phyllite and chlorite-biotite phyllite intercalated with minor amounts of biotite-sericite-quartz schist. Between 7,000 and 7,600 m (23,000 and 24,900 ft), the lower part of the North Col Formation consists of biotite-quartz schist intercalated with epidote-quartz schist, biotite-calcite-quartz schist, and thin layers of quartzose marble. These metamorphic rocks appear to be the result of the metamorphism of Middle to Early Cambrian deep sea flysch composed of interbedded, mudstone, shale, clayey sandstone, calcareous sandstone, graywacke, and sandy limestone. The base of the North Col Formation is a regional low-angle normal fault called the "Lhotse detachment".[46][47][51]
Below 7,000 m (23,000 ft), the Rongbuk Formation underlies the North Col Formation and forms the base of Mount Everest. It consists of sillimanite-K-feldspar grade schist and gneiss intruded by numerous sills and dikes of leucogranite ranging in thickness from 1 cm to 1,500 m (0.4 in to 4,900 ft).[47][52] These leucogranites are part of a belt of Late Oligocene–Miocene intrusive rocks known as the Higher Himalayan leucogranite. They formed as the result of partial melting of Paleoproterozoic to Ordovician high-grade metasedimentary rocks of the Higher Himalayan Sequence about 20 to 24 million years ago during the subduction of the Indian Plate.[53]
Mount Everest consists of sedimentary and metamorphic rocks that have been faulted southward over continental crust composed of Archean granulites of the Indian Plate during the Cenozoic collision of India with Asia.[54][55][56] Current interpretations argue that the Qomolangma and North Col formations consist of marine sediments that accumulated within the continental shelf of the northern passive continental margin of India before it collided with Asia. The Cenozoic collision of India with Asia subsequently deformed and metamorphosed these strata as it thrust them southward and upward.[57][58] The Rongbuk Formation consists of a sequence of high-grade metamorphic and granitic rocks that were derived from the alteration of high-grade metasedimentary rocks. During the collision of India with Asia, these rocks were thrust downward and to the north as they were overridden by other strata; heated, metamorphosed, and partially melted at depths of over 15 to 20 kilometres (9.3 to 12.4 mi) below sea level; and then forced upward to surface by thrusting towards the south between two major detachments.[59] The Himalayas are rising by about 5 mm per year.
There is very little native flora or fauna on Everest. A moss grows at 6,480 metres (21,260 ft) on Mount Everest.[60] It may be the highest altitude plant species.[60] An alpine cushion plant called Arenaria is known to grow below 5,500 metres (18,000 ft) in the region.[61] According to the study based on satellite data from 1993 to 2018, vegetation is expanding in the Everest region. Researchers have found plants in areas that were previously deemed bare.[62]
Euophrys omnisuperstes, a minute black jumping spider, has been found at elevations as high as 6,700 metres (22,000 ft), possibly making it the highest confirmed non-microscopic permanent resident on Earth. It lurks in crevices and may feed on frozen insects that have been blown there by the wind. There is a high likelihood of microscopic life at even higher altitudes.[63]
Birds, such as the bar-headed goose, have been seen flying at the higher altitudes of the mountain, while others, such as the chough, have been spotted as high as the Euophrys omnisuperstes, a minute black jumping spider, has been found at elevations as high as 6,700 metres (22,000 ft), possibly making it the highest confirmed non-microscopic permanent resident on Earth. It lurks in crevices and may feed on frozen insects that have been blown there by the wind. There is a high likelihood of microscopic life at even higher altitudes.[63]
Birds, such as the bar-headed goose, have been seen flying at the higher altitudes of the mountain, while others, such as the chough, have been spotted as high as the South Col at 7,920 metres (25,980 ft).[64] Yellow-billed choughs have been seen as high as 7,900 metres (26,000 ft) and bar-headed geese migrate over the Himalayas.[65] In 1953, George Lowe (part of the expedition of Tenzing and Hillary) said that he saw bar-headed geese flying over Everest's summit.[66]
Yaks are often used to haul gear for Mount Everest climbs. They can haul 100 kg (220 pounds), have thick fur and large lungs.[61] One common piece of advice for those in the Everest region is to be on the higher ground when around yaks and other animals, as they can knock people off the mountain if standing on the downhill edge of a trail.[67] Other animals in the region include the Himalayan tahr which is sometimes eaten by the snow leopard.[68] The Himalayan black bear can be found up to about 4,300 metres (14,000 ft) and the red panda is also present in the region.[69] One expedition found a surprising range of species in the region including a pika and ten new species of ants.[70]
In 2008, a new weather station at about 8,000 m altitude (26,246 feet) went online.[74] The station's first data in May 2008 were air temperature −17 °C (1 °F), relative humidity 41.3 percent, atmospheric pressure 382.1 hPa (38.21 kPa), wind direction 262.8°, wind speed 12.8 m/s (28.6 mph, 46.1 km/h), global solar radiation 711.9 watts/m2, solar UVA radiation 30.4 W/m2.[74] The project was orchestrated by Stations at High Altitude for Research on the Environment (SHARE), which also placed the Mount Everest webcam in 2011.[74][75] The solar-powered weather station is on the South Col.[76]
One of the issues facing climbers is the frequent presence of high-speed winds.[77] The peak of Mount Everest extends into the upper troposphere and penetrates the stratosphere,[78] which can expose it to the fast and freezing winds of the jet stream.[79] 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.[77] 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.[79] The reduction in oxygen availability comes from the reduced overall pressure, not a reduction in the ratio of oxygen to other gases.[80]
In the summer, the Indian monsoon brings warm wet air from the Indian Ocean to Everest's south side. During the winter, the west-southwest flowing jet stream shifts south and blows on the peak.[citation needed]
Expeditions
[77] The peak of Mount Everest extends into the upper troposphere and penetrates the stratosphere,
[78] which can expose it to the fast and freezing winds of the
jet stream.
[79] 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.
[77] 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.
[79] The reduction in oxygen availability comes from the reduced overall pressure, not a reduction in the ratio of oxygen to other gases.
[80]
In the summer, the Indian monsoon brings warm wet air from the Indian Ocean to Everest's south side. During the winter, the west-southwest flowing jet stream shifts south and blows on the peak.[citation needed]
Because Mount Everest is the highest mountain in the world, it has attracted considerable attention and climbing attempts. Whether the mountain was climbed in ancient times is unknown. It may have been climbed in 1924, although this has never been confirmed, as both of the men making the attempt failed to return from the mountain. Several climbing routes has been established over several decades of climbing expeditions to the mountain.[81][82][better source needed]
Overview
Everest's first known summiting occurred by 1953, and interest by climbers increased.[83] Despite the effort and attention poured into expeditions, only about 200 people had sumitted by 1987.[83] Everest remained a difficult climb for decades, even for serious attempts by professional climbers and large national expeditions, which were the norm until the commercial era began in the 1990s.[84]
By March 2012, Everest had been climbed 5,656 times with 223 deaths.[85] Although lower mountains have longer or steeper climbs, Everest is so high the jet stream can hit it. Climbers can be faced with winds beyond 320 km/h (200 mph) when the weather shifts.[86] At certain times of the year the jet stream shifts north, providing periods of relative calm at the mountain.[87] Other dangers include blizzards and avalanches.[87]
By 2013, The Himalayan Database recorded 6,871 summits by 4,042 different people.[88]
Early attempts
In 1885, Clinton Thomas Dent, president of the Alpine Club, suggested that climbing Mount Everest was possible in his book Above the Snow Line<
Everest's first known summiting occurred by 1953, and interest by climbers increased.[83] Despite the effort and attention poured into expeditions, only about 200 people had sumitted by 1987.[83] Everest remained a difficult climb for decades, even for serious attempts by professional climbers and large national expeditions, which were the norm until the commercial era began in the 1990s.[84]
By March 2012, Everest had been climbed 5,656 times with 223 de
By March 2012, Everest had been climbed 5,656 times with 223 deaths.[85] Although lower mountains have longer or steeper climbs, Everest is so high the jet stream can hit it. Climbers can be faced with winds beyond 320 km/h (200 mph) when the weather shifts.[86] At certain times of the year the jet stream shifts north, providing periods of relative calm at the mountain.[87] Other dangers include blizzards and avalanches.[87]
By 2013, The Himalayan Database recorded 6,871 summits by 4,042 different people.[88]
In 1885, Clinton Thomas Dent, president of the Alpine Club, suggested that climbing Mount Everest was possible in his book Above the Snow Line.[89]
The northern approach to the mountain was discovered by George Mallory and Guy Bullock on the initial 1921 British Reconnaissance Expedition. It was an exploratory expedition not equipped for a serious attempt to climb the mountain. With Mallory leading (and thus becoming the first European to set foot on Everest's flanks) they climbed the North Col to an altitude of 7,005 metres (22,982 ft). From there, Mallory espied a route to the top, but the party was unprepared for the great task of climbing any further and descended.
The British returned for a 1922 expedition. George Finch climbed using oxygen for the first time. He ascended at a remarkable speed—290 metres (951 ft) per hour, and reached an altitude of 8,320 m (27,300 ft), the first time a human reported to climb higher than 8,000 m. Mallory and Col. Felix Norton made a second unsuccessful attempt. Mallory was faulted[citation needed] for leading a group down from the North Col which got caught in an avalanche. Mallory was pulled down too but survived. Seven native porters were killed.
The next expedition was in 1924. The initial attempt by Mallory and Geoffrey Bruce was aborted when weather conditions prevented the establishment of Camp VI. The next attempt was that of Norton and Somervell, who climbed without oxygen and in perfect weather, traversing the North Face into the Great Couloir. Norton managed to reach 8,550 m (28,050 ft), though he ascended only 30 m (98 ft) or so in the last hour. Mallory rustled up oxygen equipment for a last-ditch effort. He chose young Andrew Irvine as his partner.
On 8 June 1924, George Mallory and Andrew Irvine made an attempt on the summit via the North Col-North Ridge-Northeast Ridge route from which they never returned. On 1 May 1999, the Mallory and Irvine Research Expedition found Mallory's body on the North Face in a snow basin below and to the west of the traditional site of Camp VI. Controversy has raged in the mountaineering community whether one or both of them reached the summit 29 years before the confirmed ascent and safe descent of Everest by Sir Edmund Hillary and Tenzing Norgay in 1953.
In 1933, Lady Houston, a British millionairess, funded the Houston Everest Flight of 1933, which saw a formation of two aeroplanes led by the Marquess of Clydesdale fly over the Everest summit.In 1933, Lady Houston, a British millionairess, funded the Houston Everest Flight of 1933, which saw a formation of two aeroplanes led by the Marquess of Clydesdale fly over the Everest summit.[90][91][92][93]
Early expeditions—such as Charles Bruce's in the 1920s and Hugh Ruttledge's two unsuccessful attempts in 1933 and 1936—tried to ascend the mountain from Tibet, via the North Face. Access was closed from the north to Western expeditions in 1950 after China took control of Tibet. In 1950, Bill Tilman and a small party which included Charles Houston, Oscar Houston, and Betsy Cowles undertook an exploratory expedition to Everest through Nepal along the route which has now become the standard approach to Everest from the south.[94]
The 1952 Swiss Mount Everest Expedition, led by Edouard Wyss-Dunant, was granted permission to attempt a climb from Nepal. It established a route through the Khumbu icefall and ascended to the South Col at an elevation of 7,986 m (26,201 ft). Raymond Lambert and Sherpa Tenzing Norgay were able to reach an elevation of about 8,595 m (28,199 ft) on the southeast ridge, setting a new climbing altitude record. Tenzing's experience was useful when he was hired to be part of the British expedition in 1953.[95] One reference says that no attempt at an ascent of Everest was ever under consideration in this case,[96]
although John Hunt (who met the team in Zurich on their return) wrote that when the Swiss Expedition "just failed" in the spring they decided to make another post-monsoon (summit ascent) attempt in the autumn; although as it was only decided in June the second party arrived too late, when winter winds were buffeting the mountain.[97]
In 1953, a ninth British expedition, led by John Hunt, returned to Nepal. Hunt selected two climbing pairs to attempt to reach the summit. The first pair, Tom Bourdillon and Charles Evans, came within 100 m (330 ft) of the summit on 26 May 1953, but turned back after running into oxygen problems. As planned, their work in route finding and breaking trail and their oxygen caches were of great aid to the following pair. Two days later, the expedition made its second assault on the summit with the second climbing pair: the New Zealander Edmund Hillary and Tenzing Norgay, a Nepali Sherpa climber. They reached the summit at 11:30 local time on 29 May 1953 via the South Col route. At the time, both acknowledged it as a team effort by the whole expedition, but Tenzing revealed a few years later that Hillary had put his foot on the summit first.[98] They paused at the summit to take photographs and buried a few sweets and a small cross in the snow before descending.
News of the expedition's success reached London on the morning of Queen Elizabeth II's coronation, 2 June. A few days later, the Queen gave orders that Hunt (a Briton) and Hillary (a New Zealander) were to be knighted in the Order of the British Empire for the ascent.[99] Tenzing, a Nepali Sherpa who was a citizen of India, was granted the George Medal by the UK. Hunt was ultimately made a life peer in Britain, while Hillary became a founding member of the Order of New Zealand.[100] Hillary and Tenzing have also been recognised in Nepal. In 2009, statues were raised in their honor, and in 2014, Hillary Peak and Tenzing Peak were named for them.Elizabeth II's coronation, 2 June. A few days later, the Queen gave orders that Hunt (a Briton) and Hillary (a New Zealander) were to be knighted in the Order of the British Empire for the ascent.[99] Tenzing, a Nepali Sherpa who was a citizen of India, was granted the George Medal by the UK. Hunt was ultimately made a life peer in Britain, while Hillary became a founding member of the Order of New Zealand.[100] Hillary and Tenzing have also been recognised in Nepal. In 2009, statues were raised in their honor, and in 2014, Hillary Peak and Tenzing Peak were named for them.[101][102]
On 23 May 1956 Ernst Schmied and Juerg Marmet ascended.[103] This was followed by Dölf Reist and Hans-Rudolf von Gunten on 24 May 1957.[103] Wang Fuzhou, Gonpo and Qu Yinhua of China made the first reported ascent of the peak from the North Ridge on 25 May 1960.[9] The first American to climb Everest, Jim Whittaker, joined by Nawang Gombu, reached the summit on 1 May 1963.[104][105]
1970s
Saburo Matsukata, working on finding a new route up the southwest face. Another element of the expedition was an attempt to ski Mount Everest.
[84] Despite a staff of over one hundred people and a decade of planning work, the expedition suffered eight deaths and failed to summit via the planned routes.
[84] However, Japanese expeditions did enjoy some successes. For example,
Yuichiro Miura became the first man to ski down Everest from the South Col (he descended nearly 4,200 vertical feet from the South Col before falling with extreme injuries). Another success was an expedition that put four on the summit via the South Col route.
[84][107][108] Miura's exploits became the subject of film, and he went on to become the oldest person to summit Mount Everest in 2003 at age 70 and again in 2013 at the age of 80.
[109]
In 1975, Junko Tabei, a Japanese woman, became the first woman to summit Mount Everest.[84]
In 1975, Junko Tabei, a Japanese woman, became the first woman to summit Mount Everest.[84]
In 1978, Reinhold Messner and Peter Habeler made the first ascent of Everest without supplemental oxygen.