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Mount Everest
Everest kalapatthar.jpg
Mount Everest as viewed from Kalapatthar.
Highest point
Elevation8,848 m (29,029 ft) Edit this on Wikidata[1]
Ranked 1st
Prominence
Ranked 1st
(Notice special definition for Everest)
ListingSeven Summits
Eight-thousander
Country high point
Ultra
Coordinates27°59′17″N 86°55′31″E / 27.98806°N 86.92528°E / 27.98806; 86.92528Coordinates: 27°59′17″N 86°55′31″E / 27.98806°N 86.92528°E / 27.98806; 86.92528[2]
Naming
Native name
  • सगरमाथा (Sagarmāthā)
  • ཇོ་མོ་གླང་མ (Chomolungma)
  • 珠穆朗玛峰 (Zhūmùlǎngmǎ Fēng)
Geography
Mount Everest is located in Province No. 1
Mount Everest
Mount Everest
Location on the Province No. 1, Nepal – Tibet Autonomous Region, China border
Nepali: सगरमाथा [sʌɡʌrmatʰa] , IAST: Sagarmāthā; Tibetan: Chomolungma ཇོ་མོ་གླང་མ; Chinese: 珠穆朗玛 Zhūmùlǎngmǎ) is Earth's highest mountain above sea level, located in the Mahalangur Himal sub-range of the Himalayas. The China–Nepal border runs across its summit point.[5]

The current official elevation of 8,848 m (29,029 ft), recognised by China and Nepal, was established by a 1955 Indian survey and confirmed by a 1975 Chinese survey.[1]

In 1865, Everest was given its official English name by the Royal Geographical Society, as recommended by Andrew Waugh, the British Surveyor General of India, who chose the name of his predecessor in the post, Sir George Everest, despite Everest's objections.[6]

Mount Everest attracts many climbers, some of them highly experienced mountaineers. There are two main climbing routes, one approaching the summit from the southeast in Nepal (known as the "standard route") and the other from the north in Tibet. While not posing substantial technical climbing challenges on the standard route, Everest presents dangers such as altitude sickness, weather, and wind, as well as significant hazards from avalanches and the Khumbu Icefall. As of 2019, over 300 people have died on Everest,[7] many of whose bodies remain on the mountain.[8]

The first recorded efforts to reach Everest's summit were made by British mountaineers. As Nepal did not allow foreigners to enter the country at the time, the British made several attempts on the north ridge route from the Tibetan side. After the first reconnaissance expedition by the British in 1921 reached 7,000 m (22,970 ft) on the North Col, the 1922 expedition pushed the north ridge route up to 8,320 m (27,300 ft), marking the first time a human had climbed above 8,000 m (26,247 ft). Seven porters were killed in an avalanche on the descent from the North Col. The 1924 expedition resulted in one of the greatest mysteries on Everest to this day: George Mallory and Andrew Irvine made a final summit attempt on 8 June but never returned, sparking debate as to whether or not they were the first to reach the top. They had been spotted high on the mountain that day but disappeared in the clouds, never to be seen again, until Mallory's body was found in 1999 at 8,155 m (26,755 ft) on the north face. Tenzing Norgay and Edmund Hillary made the first official ascent of Everest in 1953, using the southeast ridge route. Norgay had reached 8,595 m (28,199 ft) the previous year as a member of the 1952 Swiss expedition. The Chinese mountaineering team of Wang Fuzhou, Gonpo, and Qu Yinhua made the first reported ascent of the peak from the north ridge on 25 May 1960.[9]

Name

The name "Mount Everest" was first proposed in this 1856 speech, later published in 1857, in which the mountain was first confirmed as the world's highest

The Tibetan name for Everest is Qomolangma (ཇོ་མོ་གླང་མ, lit. "Holy Mother"). The name was first recorded with a Chinese transcription on the 1721 Kangxi Atlas, and then appeared as Tchoumour Lancma on a 1733 map published in Paris by the French geographer D'Anville based on the former map.[10] It is also popularly romanised as Chomolungma and (in Wylie) as Jo-mo-glang-ma.[15] The official Chinese transcription is 珠穆朗玛峰 (t 珠穆朗瑪峰), whose pinyin form is Zhūmùlǎngmǎ Fēng. It is also infrequently simply translated into Chinese as Shèngmǔ Fēng (t 聖母峰, s 圣母峰, lit. "Holy Mother Peak"). Many other local names exist, including "Deodungha" ("Holy Mountain") in Darjeeling.[16]

In the late 19th century, many European cartographers incorrectly believed that a native name for the mountain was Gaurishankar, a mountain between Kathmandu and Everest.[17]

In 1849, the British survey wanted to preserve local names if possible (e.g., Kangchenjunga and Dhaulagiri), Waugh argued that he could not find any commonly used local name. Waugh's search for a local name was hampered by Nepal and Tibet's exclusion of foreigners. Waugh argued that because there were many local names, it would be difficult to favour one name over all others; he decided that Peak XV should be named after British surveyor Sir George Everest, his predecessor as Surveyor General of India.[18][19][20] Everest himself opposed the name suggested by Waugh and told the Royal Geographical Society in 1857 that "Everest" could not be written in Hindi nor pronounced by "the native of India". Waugh's proposed name prevailed despite the objections, and in 1865, the Royal Geographical Society officially adopted Mount Everest as the name for the highest mountain in the world.[18] The modern pronunciation of Everest (/ˈɛvərɪst/)[21] is different from Sir George's pronunciation of his surname (/ˈ[1]

In 1865, Everest was given its official English name by the Royal Geographical Society, as recommended by Andrew Waugh, the British Surveyor General of India, who chose the name of his predecessor in the post, Sir George Everest, despite Everest's objections.[6]

Mount Everest attracts many climbers, some of them highly experienced mountaineers. There are two main climbing routes, one approaching the summit from the southeast in Nepal (known as the "standard route") and the other from the north in Tibet. While not posing substantial technical climbing challenges on the standard route, Everest presents dangers such as altitude sickness, weather, and wind, as well as significant hazards from avalanches and the Khumbu Icefall. As of 2019, over 300 people have died on Everest,[7] many of whose bodies remain on the mountain.[8]

The first recorded efforts to reach Everest's summit were made by British mountaineers. As Nepal did not allow foreigners to enter the country at the time, the British made several attempts on the north ridge route from the Tibetan side. After the first reconnaissance expedition by the British in 1921 reached 7,000 m (22,970 ft) on the North Col, the 1922 expedition pushed the north ridge route up to 8,320 m (27,300 ft), marking the first time a human had climbed above 8,000 m (26,247 ft). Seven porters were killed in an avalanche on the descent from the North Col. The 1924 expedition resulted in one of the greatest mysteries on Everest to this day: George Mallory and Andrew Irvine made a final summit attempt on 8 June but never returned, sparking debate as to whether or not they were the first to reach the top. They had been spotted high on the mountain that day but disappeared in the clouds, never to be seen again, until Mallory's body was found in 1999 at 8,155 m (26,755 ft) on the north face. Tenzing Norgay and Edmund Hillary made the first official ascent of Everest in 1953, using the southeast ridge route. Norgay had reached 8,595 m (28,199 ft) the previous year as a member of the 1952 Swiss expedition. The Chinese mountaineering team of Wang Fuzhou, Gonpo, and Qu Yinhua made the first reported ascent of the peak from the north ridge on 25 May 1960.[9]

The name "Mount Everest" was first proposed in this 1856 speech, later published in 1857, in which the mountain was first confirmed as the world's highest

The Tibetan name for Everest is Qomolangma (ཇོ་མོ་གླང་མ, lit. "Holy Mother"). The name was first recorded with a Chinese transcription on the 1721 Kangxi Atlas, and then appeared as Tchoumour Lancma on a 1733 map published in Paris by the French geographer D'Anville based on the former map.[10] It is also popularly romanised as Chomolungma and (in Wylie) as Jo-mo-glang-ma.[15] The official Chinese transcription is 珠穆朗玛峰 (t 珠穆朗瑪峰), whose pinyin form is Zhūmùlǎngmǎ Fēng. It is also infrequently simply translated into Chinese as Shèngmǔ Fēng (t 聖母峰, s 圣母峰, lit. "Holy Mother Peak"). Many other local names exist, including "Deodungha" ("Holy Mountain") in Darjeeling.[16]

In the late 19th century, many European cartographers incorrectly believed that a native name for the mountain was Gaurishankar, a mountain between Kathmandu and Everest.[17]

In 1849, the British survey wanted to preserve local names if possible (e.g., Kangchenjunga and Dhaulagiri), Waugh argued that he could not find any commonly used local name. Waugh's search for a local name was hampered by Nepal and Tibet's exclusion of foreigners. Waugh argued that because there were many local names, it would be difficult to favour one name over all others; he decided that Peak XV should be named after British surveyor Sir George Everest, his predecessor as Surveyor General of India.[18][19][20] Everest himself opposed the name suggested by Waugh and told the Royal Geographical Society in 1857 that "Everest" could not be written in Hindi nor pronounced by "the native of India". Waugh's proposed name prevailed despite the objections, and in 1865, the Royal Geographical Society officially adopted Mount Everest as the name for the highest mountain in the world.[18] The modern pronunciation of Everest (/ˈɛvərɪst/)[21] is different from Sir George's pronunciation of his surname (/ˈvrɪst/ EEV-rist).[22]

In the early 1960s, the Nepalese government coined the Nepali name Sagarmāthā or Sagar-Matha[23] (सागर-मथ्था, lit. "goddess of the sky"[24]).[25]

Surveys

19th-century surveys

Mount Everest is located in Nepal.
Mount Everest is located in Nepal.Tibetan name for Everest is Qomolangma (ཇོ་མོ་གླང་མ, lit. "Holy Mother"). The name was first recorded with a Chinese transcription on the 1721 Kangxi Atlas, and then appeared as Tchoumour Lancma on a 1733 map published in Paris by the French geographer D'Anville based on the former map.[10] It is also popularly romanised as Chomolungma and (in Wylie) as Jo-mo-glang-ma.[15] The official Chinese transcription is 珠穆朗玛峰 (t 珠穆朗瑪峰), whose pinyin form is Zhūmùlǎngmǎ Fēng. It is also infrequently simply translated into Chinese as Shèngmǔ Fēng (t 聖母峰, s 圣母峰, lit. "Holy Mother Peak"). Many other local names exist, including "Deodungha" ("Holy Mountain") in Darjeeling.[16]

In the late 19th century, many European cartographers incorrectly believed that a native name for the mountain was Gaurishankar, a mountain between Kathmandu and Everest.[17]

In 1849, the British survey wanted to preserve local names if possible (e.g., Kangchenjunga and Dhaulagiri), Waugh argued that he could not find any commonly used local name. Waugh's search for a local name was hampered by Nepal and Tibet's exclusion of foreigners. Waugh argued that because there were many local names, it would be difficult to favour one name over all others; he decided that Peak XV should be named after British surveyor Sir George Everest, his predecessor as Surveyor General of India.[18][19][20] Everest himself opposed the name suggested by Waugh and told the Royal Geographical Society in 1857 that "Everest" could not be written in Hindi nor pronounced by "the native of India". Waugh's proposed name prevailed despite the objections, and in 1865, the Royal Geographical Soci

In the late 19th century, many European cartographers incorrectly believed that a native name for the mountain was Gaurishankar, a mountain between Kathmandu and Everest.[17]

In 1849, the British survey wanted to preserve local names if possible (e.g., Kangchenjunga and Dhaulagiri), Waugh argued that he could not find any commonly used local name. Waugh's search for a local name was hampered by Nepal and Tibet's exclusion of foreigners. Waugh argued that because there were many local names, it would be difficult to favour one name over all others; he decided that Peak XV should be named after British surveyor Sir George Everest, his predecessor as Surveyor General of India.[18][19][20] Everest himself opposed the name suggested by Waugh and told the Royal Geographical Society in 1857 that "Everest" could not be written in Hindi nor pronounced by "the native of India". Waugh's proposed name prevailed despite the objections, and in 1865, the Royal Geographical Society officially adopted Mount Everest as the name for the highest mountain in the world.[18] The modern pronunciation of Everest (/ˈɛvərɪst/)[21] is different from Sir George's pronunciation of his surname (/ˈvrɪst/ EEV-rist).[22]

In the early 1960s, the Nepalese government coined the Nepali name Sagarmāthā or Sagar-Matha[23] (सागर-मथ्था, lit. "goddess of the sky"[24]).[25]

In 1802, the British began the Great Trigonometric Survey of India to fix the locations, heights, and names of the world's highest mountains. Starting in southern India, the survey teams moved northward using giant theodolites, each weighing 500 kg (1,100 lb) and requiring 12 men to carry, to measure heights as accurately as possible. They reached the Himalayan foothills by the 1830s, but Nepal was unwilling to allow the British to enter the country due to suspicions of their intentions. Several requests by the surveyors to enter Nepal were turned down.[18]

The British were forced to continue their observations from Terai, a region south of Nepal which is parallel to the Himalayas. Conditions in Terai were difficult because of torrential rains and malaria. Three survey officers died from malaria while two others had to retire because of failing health.[18]

Nonetheless, in 1847, the British continued the survey and began detailed observations of the Himalayan peaks from observation stations up to 240 km (150 mi) distant. Weather restricted work to the last three months of the year. In November 1847, Andrew Waugh, the British Surveyor General of India made several observations from the Sawajpore station at the east end of the Himalayas. Kangchenjunga was then considered the highest peak in the world, and with interest, he noted a peak beyond it, about 230 km (140 mi) away. John Armstrong, one of Waugh's subordinates, also saw the peak from a site farther west and called it peak "b". Waugh would later write that the observations indicated that peak "b" was higher than Kangchenjunga, but given the great distance of the observations, closer observations were required for verification. The following year, Waugh sent a survey official back to Terai to make closer observations of peak "b", but clouds thwarted his attempts.[18]

In 1849, Waugh dispatched James Nicolson to the area, who made two observations from Jirol, 190 km (120 mi) away. Nicolson then took the largest theodolite and headed east, obtaining over 30 observations from five different locations, with the closest being 174 km (108 mi) from the peak.[18]

Nicolson retreated to Patna on the Ganges to p

The British were forced to continue their observations from Terai, a region south of Nepal which is parallel to the Himalayas. Conditions in Terai were difficult because of torrential rains and malaria. Three survey officers died from malaria while two others had to retire because of failing health.[18]

Nonetheless, in 1847, the British continued the survey and began detailed observations of the Himalayan peaks from observation stations up to 240 km (150 mi) distant. Weather restricted work to the last three months of the year. In November 1847, Andrew Waugh, the British Surveyor General of India made several observations from the Sawajpore station at the east end of the Himalayas. Kangchenjunga was then considered the highest peak in the world, and with interest, he noted a peak beyond it, about 230 km (140 mi) away. John Armstrong, one of Waugh's subordinates, also saw the peak from a site farther west and called it peak "b". Waugh would later write that the observations indicated that peak "b" was higher than Kangchenjunga, but given the great distance of the observations, closer observations were required for verification. The following year, Waugh sent a survey official back to Terai to make closer observations of peak "b", but clouds thwarted his attempts.[18]

In 1849, Waugh dispatched James Nicolson to the area, who made two observations from Jirol, 190 km (120 mi) away. Nicolson then took the largest theodolite and headed east, obtaining over 30 observations from five different locations, with the closest being 174 km (108 mi) from the peak.[18]

Nicolson retreated to Patna on the Ganges to perform the necessary calculations based on his observations. His raw data gave an average height of 9,200 m (30,200 ft) for peak "b", but this did not consider light refraction, which distorts heights. However, the number clearly indicated that peak "b" was higher than Kangchenjunga. Nicolson contracted malaria and was forced to return home without finishing his calculations. Michael Hennessy, one of Waugh's assistants, had begun designating peaks based on Roman numerals, with Kangchenjunga named Peak IX. Peak "b" now became known as Peak XV.[18]

In 1852, stationed at the survey headquarters in Dehradun, Radhanath Sikdar, an Indian mathematician and surveyor from Bengal was the first to identify Everest as the world's highest peak, using trigonometric calculations based on Nicolson's measurements.[26] An official announcement that Peak XV was the highest was delayed for several years as the calculations were repeatedly verified. Waugh began work on Nicolson's data in 1854, and along with his staff spent almost two years working on the numbers, having to deal with the problems of light refraction, barometric pressure, and temperature over the vast distances of the observations. Finally, in March 1856 he announced his findings in a letter to his deputy in Calcutta. Kangchenjunga was declared to be 8,582 m (28,156 ft), while Peak XV was given the height of 8,840 m (29,002 ft). Waugh concluded that Peak XV was "most probably the highest in the world".[18] Peak XV (measured in feet) was calculated to be exactly 29,000 ft (8,839.2 m) high, but was publicly declared to be 29,002 ft (8,839.8 m) in order to avoid the impression that an exact height of 29,000 feet (8,839.2 m) was nothing more than a rounded estimate.[27] Waugh is sometimes playfully credited with being "the first person to put two feet on top of Mount Everest".[28]

In 1856, Andrew Waugh announced Everest (then known as Peak XV) as 8,840 m (29,002 ft) high, after several years of calculations based on observations made by the Great Trigonometric Survey.[29] The 8,848 m (29,029 ft) height given is officially recognised by Nepal and China.[30] Nepal plans a new survey in 2019 to determine if the April 2015 Nepal earthquake affected the height of the mountain.[31]

In 1955, the elevation of 8,848 m (29,029 ft) was first determined by an Indian survey, made closer to the mountain, also using theodolites.[citation needed] In 1975 it was subsequently reaffirmed by a Chinese measurement of 8,848.13 m (29,029.30 ft).[32] In both cases the snow cap, not the rock head, was measured. In May 1999 an American Everest Expedition, directed by Bradford Washburn, anchored a GPS unit into the highest bedrock. A rock head elevation of 8,850 m (29,035 ft), and a snow/ice elevation 1 m (3 ft) higher, were obtained via this device.[33] Although as of 2001, it has not been officially recognised by Nepal,[34] this figure is widely quoted. Geoid uncertainty casts doubt upon the accuracy claimed by both the 1999 and 2005 [See below] surveys.[citation needed]

In 1955, a detailed photogrammetric map (at a scale of 1:50,000) of the Khumbu region, including the south side of Mount Everest, was made by theodolites.[citation needed] In 1975 it was subsequently reaffirmed by a Chinese measurement of 8,848.13 m (29,029.30 ft).[32] In both cases the snow cap, not the rock head, was measured. In May 1999 an American Everest Expedition, directed by Bradford Washburn, anchored a GPS unit into the highest bedrock. A rock head elevation of 8,850 m (29,035 ft), and a snow/ice elevation 1 m (3 ft) higher, were obtained via this device.[33] Although as of 2001, it has not been officially recognised by Nepal,[34] this figure is widely quoted. Geoid uncertainty casts doubt upon the accuracy claimed by both the 1999 and 2005 [See below] surveys.[citation needed]

In 1955, a detailed photogrammetric map (at a scale of 1:50,000) of the Khumbu region, including the south side of Mount Everest, was made by Erwin Schneider as part of the 1955 International Himalayan Expedition, which also attempted Lhotse.

In the late 1980s, an even more detailed topographic map of the Everest area was made under the direction of Bradford Washburn, using extensive aerial photography.[35]

On 9 October 2005, after several months of measurement and calculation, the Chinese Academy of Sciences and State Bureau of Surveying and Mapping announced the height of Everest as 8,844.43 m (29,017.16 ft) with accuracy of ±0.21 m (8.3 in), claiming it was the most accurate and precise measurement to date.[36][37] This height is based on the highest point of rock and not the snow and ice covering it. The Chinese team measured a snow-ice depth of 3.5 m (11 ft),[32] which is in agreement with a net elevation of 8,848 m (29,029 ft). An argument arose between China and Nepal as to whether the official height should be the rock height (8,844 m, China) or the snow height (8,848 m, Nepal). In 2010, both sides agreed that the height of Everest is 8,848 m, and Nepal recognises China's claim that the rock height of Everest is 8,844 m.[38]

It is thought that the plate te

It 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 OligoceneMiocene 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