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Everest from Gokyo Ri in Nepal
|Elevation||8,848 m (29,029 ft)
|Prominence||8,848 m (29,029 ft)
(Notice special definition for Everest)
|Listing|| Seven Summits
Country high point
|Location|| Solukhumbu District, Sagarmatha Zone, Nepal
Tingri County, Shigatse Prefecture, Tibet Autonomous Region, People's Republic of China
|Range||Mahalangur Himal, Himalayas|
|First ascent||29 May 1953
Edmund Hillary and Tenzing Norgay
|Easiest route||South Col (Nepal)|
Mount Everest ( Nepali: सगरमाथा, Sagarmāthā; Tibetan: ཇོ་མོ་གླང་མ, Wylie: jo mo glang ma; Chomolungma or Qomolangma / / "Holy Mother"; Chinese: 珠穆朗玛峰; pinyin: Zhūmùlǎngmǎ Fēng;) is the Earth's highest mountain, with a peak at 8,848 metres (29,029 ft) above sea level and the 5th tallest mountain measured from the centre of the Earth. It is located in the Mahalangur section of the Himalayas. The international border between China and Nepal runs across the precise summit point. Its massif includes neighboring peaks Lhotse, 8,516 m (27,940 ft); Nuptse, 7,855 m (25,771 ft) and Changtse, 7,580 m (24,870 ft).
In 1856, the Great Trigonometric Survey of British India established the first published height of Everest, then known as Peak XV, at 29,002 ft (8,840 m). In 1865, Everest was given its official English name by the Royal Geographical Society upon a recommendation by Andrew Waugh, the British Surveyor General of India. Waugh named the mountain after his predecessor in the post, Sir George Everest. Although Tibetans had called Everest "Chomolungma" for centuries, Waugh was unaware of this because Nepal and Tibet were closed to foreigners.
Mount Everest attracts many highly experienced mountaineers as well as capable climbers willing to hire professional guides. While not posing substantial technical climbing challenges on the standard route, Everest presents dangers such as altitude sickness, weather and wind.
In 1802, the British began the Great Trigonometric Survey of India to determine the location 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 because of suspicions of political aggression and possible annexation. Several requests by the surveyors to enter Nepal were turned down.
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 due to failing health.
Nonetheless, in 1847, the British continued the Great Trigonometric survey and began detailed observations of the Himalayan peaks from observation stations up to 240 km (150 mi) away. 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 located in the eastern 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 officials, also saw the peak from a location 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 all attempts.
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.
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. Then, 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, while peak "b" now became known as Peak XV.
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. 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 calculations, 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 28,156 ft (8,582 m), while Peak XV was given the height of 29,002 ft (8,840 m). Waugh concluded that Peak XV was "most probably the highest in the world". 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.
While the 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. Many local names existed, including "Deodungha" ("Holy Mountain") in Darjeeling and the Tibetan "Chomolungma", which appeared on a 1733 map published in Paris by the French geographer D'Anville. In the late 19th century, many European cartographers further believed (incorrectly) that a native name for the mountain was "Gaurisankar". ( Gauri Sankar is a mountain between Kathmandu and Everest.)
Waugh argued that because there were many local names, it would be difficult to favour one name over all others, so he decided that Peak XV should be named after George Everest, his predecessor as Surveyor General of India. He wrote:
I was taught by my respected chief and predecessor, Colonel Sir George Everest, to assign to every geographical object its true local or native appellation. But here is a mountain, most probably the highest in the world, without any local name that we can discover, whose native appellation, if it has any, will not very likely be ascertained before we are allowed to penetrate into Nepal. In the meantime the privilege as well as the duty devolves on me to assign...a name whereby it may be known among citizens and geographers and become a household word among civilized nations.
George Everest 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. The modern pronunciation of Everest /ˈɛvərɨst, ˈɛvrɨst/ is different from Sir George's pronunciation of his surname, which was /ˈiːvrɨst/ (EEV-rist).
The official Tibetan name for Mount Everest is Qomolangma ( Tibetan: ཇོ་མོ་གླང་མ, Wylie: Jo mo glang ma, ZYPY: Qomolangma, often spelled Chomolungma; literally "Holy Mother"). The official Chinese name is Zhumulangma ( simplified Chinese: 珠穆朗玛峰; traditional Chinese: 珠穆朗瑪峰; pinyin: Zhūmùlǎngmǎ Fēng; literally "Qomolangma Peak") although it is sometimes known as Shengmu Feng ( simplified Chinese: 圣母峰; traditional Chinese: 聖母峰; pinyin: Shèngmǔ Fēng; literally "Holy Mother"). In the early 1960s, the Nepalese government coined a Nepali name for Mount Everest, Sagarmāthā (सगरमाथा), allegedly to supplant the Tibetan name among the locals, which the Nepali government felt was "not acceptable".
In 2002, the Chinese People's Daily newspaper published an article making a case against the use of "Mount Everest" for the mountain in English, insisting that it should be referred to as "Mount Qomolangma", based on the local Tibetan name. The article argued that British colonialists did not "first discover" the mountain, as it had been known to the Tibetans and mapped by the Chinese as "Qomolangma" since at least 1719.
The 8,848 m (29,029 ft) height given is officially recognised by Nepal and China, although Nepal is planning a new survey.
On 9 October 2005, after several months of measurement and calculation, the Chinese Academy of Sciences and State Bureau of Surveying and Mapping officially announced the height of Everest as 8,844.43 m (29,017.16 ft) with accuracy of ±0.21 m (0.69 ft). They claimed it was the most accurate and precise measurement to date. This height is based on the actual highest point of rock and not on the snow and ice covering it. The Chinese team also measured a snow/ice depth of 3.5 m (11 ft), which is in agreement with a net elevation of 8,848 m (29,029 ft). The snow and ice thickness varies over time, making a definitive height of the snow cap impossible to determine.
In 1856, Andrew Waugh announced Everest (then known as Peak XV) as 29,002 ft (8,840 m) high, after several years of calculations based on observations made by the Great Trigonometric Survey.
The elevation of 8,848 m (29,029 ft) was first determined by an Indian survey in 1955, made closer to the mountain, also using theodolites. It was subsequently reaffirmed by a 1975 Chinese measurement 8,848.13 m (29,029.30 ft). 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. Although it has not been officially recognized by Nepal, this figure is widely quoted. Geoid uncertainty casts doubt upon the accuracy claimed by both the 1999 and 2005 surveys.
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. An even more detailed topographic map of the Everest area was made in the late 1980s under the direction of Bradford Washburn, using extensive aerial photography.
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), but another account mentions more lateral movement (27 mm/1.1 in), and even shrinkage has been suggested.
The summit of Everest is the point at which the Earth's surface reaches the greatest distance above sea level. Several other mountains are sometimes claimed as alternative "tallest mountains on Earth". Mauna Kea in Hawaii is tallest when measured from its base; it rises over 10,200 m (6.3 mi) 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, Mount McKinley, in Alaska, is also taller than Everest. Despite its height above sea level of only 6,193.6 m (20,320 ft), Mount McKinley sits atop a sloping plain with elevations from 300 m (980 ft) to 900 m (3,000 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). 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).
The summit of Chimborazo in Ecuador is 2,168 m (7,113 ft) farther from the 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. 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).
Mt. Everest has two main climbing routes, the southeast ridge from Nepal and the north ridge from Tibet, as well as many other less frequently climbed routes. Of the two main routes, the southeast ridge is technically easier and is the more frequently used route. It was the route used by Edmund Hillary and Tenzing Norgay in 1953 and the first recognized of fifteen routes to the top by 1996. This was, however, a route decision dictated more by politics than by design as the Chinese border was closed to the western world in the 1950s after the People's Republic of China invaded Tibet.
Most attempts are made during May before the summer monsoon season. As the monsoon season approaches, a change in the jet stream at this time pushes it northward, thereby reducing the average wind speeds high on the mountain. While attempts are sometimes made after the monsoons in September and October, when the jet stream is again temporarily pushed northward, the additional snow deposited by the monsoons and the less stable weather patterns (tail end of the monsoon) makes climbing extremely difficult.
The ascent via the southeast ridge begins with a trek to Base Camp at 5,380 m (17,700 ft) on the south side of Everest in Nepal. Expeditions usually fly into Lukla (2,860 m) from Kathmandu and pass through Namche Bazaar. Climbers then hike to Base Camp, which usually takes six to eight days, allowing for proper altitude acclimatization in order to prevent altitude sickness. Climbing equipment and supplies are carried by yaks, dzopkyos (yak-cow hybrids) and human porters to Base Camp on the Khumbu Glacier. When Hillary and Tenzing climbed Everest in 1953, the British expedition that they were part of (over 400 climbers, porters and sherpas at that point) started from the Kathmandu Valley, as there were no roads further east at that time.
Climbers will spend a couple of weeks in Base Camp, acclimatizing to the altitude. During that time, Sherpas and some expedition climbers will set up ropes and ladders in the treacherous Khumbu Icefall. Seracs, crevasses and shifting blocks of ice make the icefall one of the most dangerous sections of the route. Many climbers and Sherpas have been killed in this section. To reduce the hazard, climbers will usually begin their ascent well before dawn, when the freezing temperatures glue ice blocks in place. Above the icefall is Camp I at 6,065 metres (19,900 ft).
From Camp I, climbers make their way up the Western Cwm to the base of the Lhotse face, where Camp II or Advanced Base Camp (ABC) is established at 6,500 m (21,300 ft). The Western Cwm is a flat, gently rising glacial valley, marked by huge lateral crevasses in the centre, which prevent direct access to the upper reaches of the Cwm. Climbers are forced to cross on the far right near the base of Nuptse to a small passageway known as the "Nuptse corner". The Western Cwm is also called the "Valley of Silence" as the topography of the area generally cuts off wind from the climbing route. The high altitude and a clear, windless day can make the Western Cwm unbearably hot for climbers.
From ABC, climbers ascend the Lhotse face on fixed ropes up to Camp III, located on a small ledge at 7,470 m (24,500 ft). From there, it is another 500 meters to Camp IV on the South Col at 7,920 m (26,000 ft). From Camp III to Camp IV, climbers are faced with two additional challenges: The Geneva Spur and The Yellow Band. The Geneva Spur is an anvil shaped rib of black rock named by the 1952 Swiss expedition. Fixed ropes assist climbers in scrambling over this snow covered rock band. The Yellow Band is a section of interlayered marble, phyllite, and semischist, which also requires about 100 meters of rope for traversing it.
On the South Col, climbers enter the death zone. Climbers typically only have a maximum of two or three days that they can endure at this altitude for making summit bids. Clear weather and low winds are critical factors in deciding whether to make a summit attempt. If weather does not cooperate within these short few days, climbers are forced to descend, many all the way back down to Base Camp.
From Camp IV, climbers will begin their summit push around midnight with hopes of reaching the summit (still another 1,000 meters above) within 10 to 12 hours. Climbers will first reach "The Balcony" at 8,400 m (27,600 ft), a small platform where they can rest and gaze at peaks to the south and east in the early light of dawn. Continuing up the ridge, climbers are then faced with a series of imposing rock steps which usually forces them to the east into waist-deep snow, a serious avalanche hazard. At 8,750 m (28,700 ft), a small table-sized dome of ice and snow marks the South Summit.
From the South Summit, climbers follow the knife-edge southeast ridge along what is known as the "Cornice traverse", where snow clings to intermittent rock. This is the most exposed section of the climb as a misstep to the left would send one 2,400 m (8,000 ft) down the southwest face, while to the immediate right is the 3,050 m (10,000 ft) Kangshung face. At the end of this traverse is an imposing 12 m (40 ft) rock wall called the "Hillary Step" at 8,760 m (28,740 ft).
Hillary and Tenzing were the first climbers to ascend this step and they did it with primitive ice climbing equipment and ropes. Nowadays, climbers will ascend this step using fixed ropes previously set up by Sherpas. Once above the step, it is a comparatively easy climb to the top on moderately angled snow slopes—though the exposure on the ridge is extreme, especially while traversing large cornices of snow. With increasing numbers of people climbing the mountain in recent years, the Step has frequently become a bottleneck, with climbers forced to wait significant amounts of time for their turn on the ropes, leading to problems in getting climbers efficiently up and down the mountain. After the Hillary Step, climbers also must traverse a loose and rocky section that has a large entanglement of fixed ropes that can be troublesome in bad weather. Climbers will typically spend less than half an hour at the summit to allow time to descend to Camp IV before darkness sets in, to avoid serious problems with afternoon weather, or because supplemental oxygen tanks run out.
The north ridge route begins from the north side of Everest in Tibet. Expeditions trek to the Rongbuk Glacier, setting up base camp at 5,180 m (16,990 ft) on a gravel plain just below the glacier. To reach Camp II, climbers ascend the medial moraine of the east Rongbuk Glacier up to the base of Changtse at around 6,100 m (20,000 ft). Camp III (ABC—Advanced Base Camp) is situated below the North Col at 6,500 m (21,300 ft). To reach Camp IV on the north col, climbers ascend the glacier to the foot of the col where fixed ropes are used to reach the North Col at 7,010 m (23,000 ft). From the North Col, climbers ascend the rocky north ridge to set up Camp V at around 7,775 m (25,500 ft). The route crosses the North Face in a diagonal climb to the base of the Yellow Band reaching the site of Camp VI at 8,230 m (27,000 ft). From Camp VI, climbers will make their final summit push. Climbers face a treacherous traverse from the base of the First Step: ascending from 8,501 metres (27,890 ft) to 8,534 m (28,000 ft), to the crux of the climb, the Second Step: ascending from 8,577 metres (28,140 ft) to 8,626 m (28,300 ft). (The Second Step includes a climbing aid called the "Chinese ladder", a metal ladder placed semi-permanently in 1975 by a party of Chinese climbers. It has been almost continuously in place since, and ladders have been used by virtually all climbers on the route.) Once above the Second Step the inconsequential Third Step is clambered over: ascending from 8,690 m (28,510 ft) to 8,800 m (28,870 ft). Once above these steps, the summit pyramid is climbed by a snow slope of 50 degrees, to the final summit ridge along which the top is reached.
See also: the Three Steps
In 1885, Clinton Thomas Dent, president of the Alpine Club, suggested that climbing Mount Everest was possible in his book Above the Snow Line.
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 ("The other George") 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 climbed higher than 8,000 m. This feat was entirely lost on the British climbing establishment—except for its "unsporting" nature. Mallory and Col. Felix Norton made a second unsuccessful attempt. Mallory was faulted for leading a group down from the North Col which got caught in an avalanche. Mallory was pulled down too, but seven native porters were killed.
The next Expedition was in 1924. The initial attempt by Mallory and Bruce was aborted when weather conditions precluded 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 of course, 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 aircraft led by the Marquess of Clydesdale fly over the summit in an effort to deploy the British Union Flag at the top.
Early expeditions—such as Bruce's in the 1920s and Hugh Ruttledge's two unsuccessful attempts in 1933 and 1936—tried to make an ascent of the mountain from Tibet, via the north face. Access was closed from the north to western expeditions in 1950, after the Chinese asserted control over 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.
The Swiss expedition of 1952, led by Edouard Wyss-Dunant, was granted permission to attempt a climb from Nepal. The expedition established a route through the Khumbu ice fall and ascended to the South Col at an elevation of 7,986 m (26,201 ft). No attempt at an ascent of Everest was ever under consideration in this case. Raymond Lambert and Sherpa Tenzing Norgay were able to reach a height 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.
First successful ascent by Tenzing and Hillary
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 caches of extra oxygen were of great aid to the following pair. Two days later, the expedition made its second and final assault on the summit with its second climbing pair, the New Zealander Edmund Hillary and Tenzing Norgay, a Nepali sherpa climber from Darjeeling, India. They reached the summit at 11:30 am 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. 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. Returning to Kathmandu a few days later, Hunt (a Briton) and Hillary (a New Zealander) discovered that they had been promptly knighted in the Order of the British Empire, a KBE, for the ascent. 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. Hillary and Tenzing are also nationally recognized in Nepal, where annual ceremonies in schools and offices celebrate their accomplishment.
By the end of the 2010 climbing season, there had been 5,104 ascents to the summit by about 3,142 individuals. Some specific "firsts" by those climbers includes:
- First climb to 8,000 m
On 23 May 1922, two members of the 1922 British Mount Everest Expedition, Australian climber George Finch and British climber Captain C. Geoffrey Bruce (cousin of Expedition leader General Charles Granville Bruce), became the first humans to ascend any mountain to 8,000 metres (26,247 ft) when they reached an altitude of 8,321 metres (27,300 ft) on the north ridge of Everest. Today it is considered a significant climbing accomplishment, achieved by only 28 climbers as of May 2012, to climb the 14 mountains on earth - the eight-thousanders - that reach and exceed 8,000 metres. At 8,321 metres, Finch and Bruce had actually exceeded the summit of 9 of the 14 eight-thousanders.
- First repeat ascent by a climber (and other multiples)
Fifteen years later, on 3 May 1980, Japanese climber Yasuo Kato became the first non-Sherpa to reach the summit a second time, following his original 1973 summit.
The first to reach the summit five times is Sungdare Sherpa, on 10 May 1988, having first summitted on 2 October 1979. The first non-Sherpa to summit five times was New Zealand climber Rob Hall on 10 May 1996, dying a few hours later in the 1996 Mount Everest disaster.
The first to reach the summit ten times is Sherpa Ang Rita, from 7 May 1983 through 23 May 1996.
The first to reach the summit fifteen times (31 May 2005) and the only one to reach it a twentieth time (22 May 2010) is Apa Sherpa, who first summitted on 10 May 1990.
- First female ascent
On 16 May 1975, Junko Tabei of Japan became the first woman to summit Everest. Tabei and her climbing partner, Sherpa Ang Tshering I, were the 38th/39th unique individuals to complete the ascent. (In 1992, Tabei became the first woman to complete the Seven Summits.)
- First ascent without supplemental oxygen
On 8 May 1978, Italian climber Reinhold Messner and Austrian climber Peter Habeler made the first ascent without supplemental oxygen, using the southeast ridge route.
- First solo ascent
On 20 August 1980, Messner became the first person to reach the summit of the mountain solo. In so doing, he was also the first to solo summit without supplementary oxygen or support, traveling the Northwest route. He climbed for three days entirely alone from his base camp at 6,500 metres (21,300 ft).
- First winter ascent
In 1980, a team from Poland led by Andrzej Zawada, with Leszek Cichy and Krzysztof Wielicki, became the first to reach the summit during the winter season. (Also first winter summit of any of the world's fourteen 8000 metre peaks.)
- First 8,848 metres (29,029 ft) ascent from sea level
On 11 May 1990, Australian climber Tim Macartney-Snape became the first person to complete a self-propelled ascent of Mount Everest from sea level to the summit. Macartney-Snape began his approximately 1,200 km (750 mi) 'Sea to Summit' expedition three months earlier, on foot, on Sagar Island in the Bay of Bengal.
- First 9,271 metres (30,417 ft) ascent from Dead Sea level
In May 2006 Briton Pauline Sanderson became the first person to complete a self-propelled ascent of Mount Everest, the highest point on the earth's surface, starting from the Dead Sea, at −423 metres (−1,388 ft) the lowest point on the earth's surface. Sanderson began her approximately 8,000 km (5,000 mi) 'EverestMax' expedition six months earlier, by bicycle, from the shore of the Dead Sea in Jordan. (Sanderson's husband, Phil, joined her for the final ascent, making them the first married British couple to summit Everest together.)
- First descent by paraglider
On 26 September 1988, shortly after summitting, French mountaineer and paraglider pilot Jean-Marc Boivin completed the first descent by paraglider. Boivin's 11-12 minute, 2,948 metres (9,700 ft) descent to Camp II holds the altitude record for start of a paraglider flight.
- First descent by ski
On 7 October 2000, Slovenian climber and extreme skier Davo Karničar became the first person to descend by ski from the summit of Everest. The descent took five hours and Karnicar reached speeds of 75 mph. (While Japanese climber and skier Yuichiro Miura is known for his 6 May 1970 feat as The Man Who Skied Down Everest, his 1,280 metres (4,199 ft) descent on skis began from Everest's 7,906 metres (25,938 ft) South Col.)
During the 1996 season, 15 people died while climbing on Mount Everest, the highest number of fatalities in a single year in the mountain's history. Eight of them died on 11 May alone. The disaster gained wide publicity and raised questions about the commercialization of climbing Mount Everest.
Journalist Jon Krakauer, on assignment from Outside magazine, was in one of the affected parties, and afterwards published the bestseller Into Thin Air, which related his experience. Anatoli Boukreev, a guide who felt impugned by Krakauer's book, co-authored a rebuttal book called The Climb. The dispute sparked a debate within the climbing community. In May 2004, Kent Moore, a physicist, and John L. Semple, a surgeon, both researchers from the University of Toronto, told New Scientist magazine that an analysis of weather conditions on 11 May suggested that freak weather caused oxygen levels to plunge approximately 14%.
The storm's impact on climbers on the North Ridge of Mount Everest, where several climbers also died, was detailed in a first-hand account by British filmmaker and writer Matt Dickinson in his book The Other Side of Everest. 16-year-old Mark Pfetzer was on the climb and wrote about it in his account, Within Reach: My Everest Story.
2005: Helicopter landing
In May 2005, pilot Didier Delsalle of France landed a Eurocopter AS350 B3 helicopter on the summit of Mount Everest. He needed to land for two minutes to set the Fédération Aéronautique Internationale (FAI) official record, but he stayed for about four minutes, twice. In this type of landing the rotors stay engaged, which avoids relying on the snow to fully support the aircraft. The flight set rotorcraft world records, for highest of both landing and take-off.
Some press reports suggested that the report of the summit landing was a misunderstanding of a South Col landing, but he had also landed on South Col two days earlier, with this landing and the Everest records confirmed by the FAI. Delsalle also rescued two Japanese climbers at 16,000 feet (4,877 meters) while he was there. One climber noted that the new record meant a better chance of rescue.
Double-amputee climber Mark Inglis revealed in an interview with the press on 23 May 2006, that his climbing party, and many others, had passed a distressed climber, David Sharp, on 15 May, sheltering under a rock overhang 450 metres (1,480 ft) below the summit, without attempting a rescue. The revelation sparked wide debate on climbing ethics, especially as applied to the arduous conditions in the death zone of the highest 850 m of Everest. The climbers who left him said that the rescue efforts would have been useless and only have caused more deaths. Much of this controversy was captured by the Discovery Channel while filming the television program Everest: Beyond the Limit. A crucial decision affecting the fate of Sharp is shown in the program, where an early returning climber (Max Chaya) is descending and radios to his base camp manager ( Russell Brice) that he has found a climber in distress. He is unable to identify Sharp, who had chosen to climb solo without any support and so did not identify himself to other climbers. The base camp manager assumes that Sharp is part of a group that has already calculated that they must abandon him, and informs his lone climber that there is no chance of him being able to help Sharp by himself. As Sharp's condition deteriorates through the day and other descending climbers pass him, his opportunities for rescue diminish: his legs and feet curl from frostbite, preventing him from walking; the later descending climbers are lower on oxygen and lack the strength to offer aid; time runs out for any Sherpas to return and rescue him. Most importantly, Sharp's decision to climb without support left him with no margin for recovery.
As this debate raged, on 26 May, Australian climber Lincoln Hall was found alive, after being declared dead the day before. He was found by a party of four climbers ( Dan Mazur, Andrew Brash, Myles Osborne and Jangbu Sherpa) who, giving up their own summit attempt, stayed with Hall and descended with him and a party of 11 Sherpas sent up to carry him down. Hall later fully recovered. Similar actions have been recorded since, including on 21 May 2007, when Canadian climber Meagan McGrath initiated the successful high-altitude rescue of Nepali Usha Bista. Recognizing her heroic rescue, Major Meagan McGrath was selected as a 2011 recipient of the Sir Edmund Hillary Foundation of Canada Humanitarian Award, which recognizes a Canadian who has personally or administratively contributed a significant service or act in the Himalayan Region of Nepal.
By the end of the 2010 climbing season, there had been 5,104 ascents to the summit by about 3,142 individuals. Some records set by those 3,000+ climbers (including new climbers and accomplishments in 2011 and 2012):
- Most times to summit
Apa Sherpa holds the record for reaching the summit more times than any other person, 21 times between 10 May 1990 and 11 May 2011. The record for a non-Sherpa is held by American climber and expedition guide Dave Hahn, reaching the summit 14 times between 19 May 1994 and 26 May 2012.
- Youngest to summit
The youngest person to climb Mount Everest was 13-year-old Jordan Romero in May 2010 from the Tibetan side. His ascent, as part of an apparent "race" to bring younger and younger children to the mountain (shortly after Romero's ascent, Pemba Dorjie Sherpa announced plans to bring his 9 year old son to the summit), triggered a wave of criticism that prompted Chinese authorities to establish age limits on Mt Everest. At the present time, China no longer grants permits to prospective climbers under 18 or over 60. Nepal sets the minimum age at 16 but has no maximum age.
- Oldest to summit/oldest male to summit
The oldest climber to reach Mount Everest's summit is 76-year-old Min Bahadur Sherchan, on 25 May 2008 from the Nepalese side. Sherchan beat the previous record set in 2007 by 71-year-old Katsusuke Yanagisawa.
- Oldest female to summit
On 19 May 2012, 73-year-old Tamae Watanabe from Japan broke the record for the oldest woman to climb Mount Everest. She reached the summit from the north side.
- Oldest to summit from both sides
The oldest climber to reach the summit of Mount Everest from both sides (Nepal and Tibet) of the mountain is 60-year-old Julio Bird, a Puerto Rican cardiologist who reached the summit of Mount Everest from the north side on 17 May 2010.
- Fastest to summit via northeast ridge, without supplemental oxygen
2007, Christian Stangl, 16 hours 42 minutes, Advanced Base Camp to the summit: The fastest ascent via the northeast ridge was accomplished in 2007 by Austrian climber Christian Stangl, who took 16h 42min for the 10 km distance from Camp III (Advanced Base Camp) to the summit, just barely beating Italian Hans Kammerlander's record of 17 hours, accomplished in 1996. Both men climbed solo. In 2010, Stangl was proven, and later confessed to, having claimed a fraudulent summit-climb of K2 in 2010.
- Fastest to summit via southeast ridge (South Col), with supplemental oxygen
2004, Pemba Dorjie Sherpa, 8 hours 10 minutes, base camp to the summit: The fastest oxygen-supported ascent over the southeast ridge (South Col) was Nepalese Pemba Dorje Sherpa's 2004 climb, taking 8h 10min for the 17-km route from base camp to the summit. Pemba's record-claim was subject to an unprecedented dispute by renowned Mt. Everest chronicler Elizabeth Hawley and other mountaineers in Nepal. Pemba was later arrested and jailed for his alleged involvement in a swindling scandal unrelated to Mt. Everest.
- Fastest to summit via southeast ridge (South Col), without supplemental oxygen
1998, Kazi Sherpa; 20 hours 24 minutes; basecamp to the summit; solo, unsupported, drug-unaided (Diamox not used): The fastest ascent without supplementary oxygen from basecamp to the summit via the southeast ridge (South Col) was set by Kazi Sherpa in 1998 in 20 hours 24 minutes, thereby breaking Marc Batard's previous record from 1988 by 2 hours and 5 minutes.
By the end of the 2010 climbing season, there had been 5,104 ascents to the summit by about 3,142 individuals, with 77% of these ascents being accomplished since 2000. The summit was achieved in 7 of the 22 years from 1953 to 1974, and has not been missed since 1975. In 2007, the record number of 633 ascents was recorded, by 350 climbers and 253 sherpas.
A remarkable illustration of the explosion of popularity of Everest is provided by the numbers of daily ascents. Analysis of the 1996 Mount Everest disaster shows that part of the blame was on the bottleneck caused by the large number of climbers (33 to 36) attempting to summit on the same day; this was considered unusually high at the time. By comparison, on 23 May 2010, the summit of Mount Everest was reached by 169 climbers - more summits in a single day than in the cumulative 31 years from the first successful summit in 1953 through 1983.
There have been 219 fatalities recorded on Mount Everest from the 1922 British Mount Everest Expedition through the end of 2010, a rate of 4.3 fatalities for every 100 summits (this is a general rate, and includes fatalities amongst support climbers, those who turned back before the peak, those who died en route to the peak and those who died while descending from the peak). Of the 219 fatalities, 58 (26.5%) were climbers who had summited but did not complete their descent. Though the rate of fatalities has decreased since the year 2000 (1.4 fatalities for every 100 summits, with 3938 summits since 2000), the significant increase in the total number of climbers still means 54 fatalities since 2000: 33 on the northeast ridge, 17 on the southeast ridge, 2 on southwest face, and 2 on north face.
Nearly all attempts at the summit are done using one of the two main routes. The traffic seen by each route varies from year to year. In 2005–07, more than half of all climbers elected to use the more challenging, but cheaper northeast route. In 2008, the northeast route was closed by the Chinese government for the entire climbing season, and the only people able to reach the summit from the north that year were athletes responsible for carrying the Olympic torch for the 2008 Summer Olympics. The route was closed to foreigners once again in 2009 in the run-up to the 50th anniversary of the Dalai Lama's exile. These closures led to declining interest in the north route, and, in 2010, two thirds of the climbers reached the summit from the south.
Climbing Mount Everest can be a relatively expensive undertaking for climbers. Climbing gear required to reach the summit may cost in excess of US$8,000 and most climbers also use bottled oxygen, which adds around $3,000. The permit to enter the Everest area from the south via Nepal costs $10,000 to $25,000 per person, depending on the size of the team. The ascent typically starts in one of the two base camps near the mountain, both of which are approximately 100 kilometres (60 mi) from Kathmandu and 300 kilometres (190 mi) from Lhasa (the two nearest cities with major airports); transferring one's equipment from the airport to the base camp may add as much as $2,000.
Beyond this point, costs may vary widely. It is technically possible to reach the summit with minimal additional expenses, and there are 'budget' travel agencies which offer logistical support for such trips. However, this is considered difficult and dangerous (as illustrated by the case of David Sharp). Many climbers hire "full service" guide companies, which provide a wide spectrum of services, including acquisition of permits, transportation to/from base camp, food, tents, fixed ropes, medical assistance while on the mountain, an experienced mountaineer guide, and even personal porters to carry one's backpack and cook one's meals. The cost of such a guide service may range from $40,000 to $80,000 per person. Since most equipment is moved by sherpas, clients of full-service guide companies can often keep their backpack weights under 10 kilograms (22 lb), or hire a sherpa to carry their backpack for them. This can be contrasted with expeditions to less commercialized peaks (for example, climbers attempting Mount McKinley are often expected to carry backpacks over 30 kilograms (66 lb) and occasionally to tow a sled with 35 kilograms (77 lb) of gear and food.)
According to Jon Krakauer, the era of commercialization of Everest started in 1985, when the summit was reached by a guided expedition led by David Breashears that included Richard Bass, a wealthy 55 year old businessman and an amateur mountain climber with only 4 years of climbing experience. By the early 1990s, multiple companies were offering guided tours to the mountain. Rob Hall, the mountaineer who died in the 1996 disaster, had successfully guided 39 clients to the summit prior to that incident.
The degree of commercialization of Mount Everest is a frequent subject of criticism. Jamling Tenzing Norgay, the son of Tenzing Norgay, said in a 2003 interview that his late father would have been shocked to discover that rich thrill-seekers with no climbing experience were now routinely reaching the summit:
You still have to climb this mountain yourself with your feet. But the spirit of adventure is not there any more. It is lost. There are people going up there who have no idea how to put on crampons. They are climbing because they have paid someone $65,000. It is very selfish. It endangers the lives of others.
Reinhold Messner concurred in 2004:
You could die in each climb and that meant you were responsible for yourself. We were real mountaineers: careful, aware and even afraid. By climbing mountains we were not learning how big we were. We were finding out how breakable, how weak and how full of fear we are. You can only get this if you expose yourself to high danger. I have always said that a mountain without danger is not a mountain. ... High-altitude alpinism has become tourism and show. These commercial trips to Everest, they are still dangerous. But the guides and organisers tell clients, "Don't worry, it's all organised." The route is prepared by hundreds of Sherpas. Extra oxygen is available in all camps, right up to the summit. People will cook for you and lay out your beds. Clients feel safe and don't care about the risks.
However, not all opinions on the subject among prominent mountaineers are strictly negative. For example, Edmund Hillary, who went on record saying that he hasn't liked "the commercialization of mountaineering, particularly of Mt. Everest" and claimed that "Having people pay $65,000 and then be led up the mountain by a couple of experienced guides ... isn't really mountaineering at all", nevertheless noted that he was pleased by the changes brought to Everest area by the Westerners:
I don’t have any regrets because I worked very hard indeed to improve the condition for the local people. When we first went in there they didn’t have any schools, they didn’t have any medical facilities, all over the years we have established 27 schools, we have two hospitals and a dozen medical clinics and then we've built bridges over wild mountain rivers and put in fresh water pipelines so in cooperation with the Sherpas we've done a lot to benefit them.
At the higher regions of Mount Everest, climbers seeking the summit typically spend substantial time within the death zone (altitudes higher than 8,000 metres (26,000 ft)), and face significant challenges to survival. Temperatures can dip to very low levels, resulting in frostbite of any body part exposed to the air. Since temperatures are so low, snow is well-frozen in certain areas and death or injury by slipping and falling can occur. High winds at these altitudes on Everest are also a potential threat to climbers.
Another significant threat to climbers is low atmospheric pressure. The atmospheric pressure at the top of Everest is about a third of sea level pressure or 0.333 standard atmospheres (337 mbar), resulting in the availability of only about a third as much oxygen to breathe.
Debilitating effects of the death zone are so great that it takes most climbers up to 12 hours to walk the distance of 1.72 kilometres (1.07 mi)) from South Col to the summit. Achieving even this level of performance requires prolonged altitude acclimatization, which takes 40–60 days for a typical expedition. A sea-level dweller exposed to the atmospheric conditions at the altitude above 28,000 feet (8,500 m) without acclimatization would likely lose consciousness within 2 to 3 minutes.
In May 2007, the Caudwell Xtreme Everest undertook a medical study of oxygen levels in human blood at extreme altitude. Over 200 volunteers climbed to Everest Base Camp where various medical tests were performed to examine blood oxygen levels. A small team also performed tests on the way to the summit.
Even at base camp, the low partial pressure of oxygen had direct effect on blood oxygen saturation levels. At sea level, blood oxygen saturation is generally 98% to 99%. At base camp, blood saturation fell to between 85% and 87%. Blood samples taken at the summit indicated very low oxygen levels in the blood. A side effect of low blood oxygen is a vastly increased breathing rate, often 80–90 breaths per minute as opposed to a more typical 20–30. Exhaustion can occur merely attempting to breathe.
Lack of oxygen, exhaustion, extreme cold, and climbing hazards all contribute to the death toll. An injured person who cannot walk is in serious trouble, since rescue by helicopter is generally impractical and carrying the person off the mountain is very risky. People who die during the climb are typically left behind. About 150 bodies have never been recovered. It is not uncommon to find corpses near the standard climbing routes.
Most expeditions use oxygen masks and tanks above 8,000 m (26,000 ft). Everest can be climbed without supplementary oxygen, but only by the most accomplished mountaineers and at increased risk. Humans do not think clearly with low oxygen, and the combination of extreme weather, low temperatures, and steep slopes often require quick, accurate decisions.
The use of bottled oxygen to ascend Mount Everest has been controversial. It was first used on the 1922 British Mount Everest Expedition by George Finch and Geoffrey Bruce who climbed up to 7,800 m (25,600 ft) at a spectacular speed of 1000 vertical feet per hour (vf/h). Pinned down by a fierce storm, they escaped death by breathing oxygen from a jury-rigged set-up during the night. The next day they climbed to 8,100 m (26,600 ft) at 900 vf/h—nearly three times as fast as non-oxygen users. Yet the use of oxygen was considered so unsportsmanlike that none of the rest of the Alpine world recognized this high ascent rate. George Mallory himself described the use of such oxygen as unsportsmanlike, but he later concluded that it would be impossible for him to summit without it and consequently used it on his final attempt in 1924. When Tenzing and Hillary made the first successful summit in 1953, they used bottled oxygen, with the expedition's physiologist Griffith Pugh referring to the oxygen debate as a "futile controversy", noting that oxygen "greatly increases subjective appreciation of the surroundings, which after all is one of the chief reasons for climbing." For the next twenty-five years, bottled oxygen was considered standard for any successful summit.
Reinhold Messner was the first climber to break the bottled oxygen tradition and in 1978, with Peter Habeler, made the first successful climb without it. Although critics alleged that he sucked mini-bottles of oxygen—a claim that Messner denied—Messner silenced them when he summited the mountain solo, without supplemental oxygen or any porters or climbing partners, on the more difficult northwest route, in 1980. Once the climbing community was satisfied that the mountain could be climbed without supplemental oxygen, many purists then took the next logical step of insisting that's how it should be climbed.
The aftermath of the 1996 disaster further intensified the debate. Jon Krakauer's Into Thin Air (1997) expressed the author's personal criticisms of the use of bottled oxygen. Krakauer wrote that the use of bottled oxygen allowed otherwise unqualified climbers to attempt to summit, leading to dangerous situations and more deaths. The 10–11 May 1996 disaster was partially caused by the sheer number of climbers (34 on that day) attempting to ascend, causing bottlenecks at the Hillary Step and delaying many climbers, most of whom summitted after the usual 2 p.m. turnaround time. He proposed banning bottled oxygen except for emergency cases, arguing that this would both decrease the growing pollution on Everest—many bottles have accumulated on its slopes—and keep marginally qualified climbers off the mountain.
The 1996 disaster also introduced the issue of the guide's role in using bottled oxygen. Guide Anatoli Boukreev's decision not to use bottled oxygen was sharply criticized by Jon Krakauer. Boukreev's supporters (who include G. Weston DeWalt, who co-wrote The Climb) state that using bottled oxygen gives a false sense of security. Krakauer and his supporters point out that, without bottled oxygen, Boukreev could not directly help his clients descend. They state that Boukreev said that he was going down with client Martin Adams, but just below the South Summit, Boukreev determined that Adams was doing fine on the descent and so descended at a faster pace, leaving Adams behind. Adams states in The Climb: "For me, it was business as usual, Anatoli's going by, and I had no problems with that."
Thefts and other crimes
Some climbers have reported life-threatening thefts from supply caches. Vitor Negrete, the first Brazilian to climb Everest without oxygen and part of David Sharp's party, died during his descent, and theft from his high-altitude camp may have contributed.
In addition to theft, the 2008 book High Crimes by Michael Kodas describes unethical guides and Sherpas, prostitution and gambling at the Tibet Base Camp, fraud related to the sale of oxygen bottles, and climbers collecting donations under the pretense of removing trash from the mountain.
Flora and fauna
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. It should be noted that there is a high likelihood of microscopic life at even higher altitudes. 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) scavenging on food, or even corpses, left by prior climbing expeditions. There is a moss that grows at 6,480 metres (21,260 ft) on Mount Everest. It may be the highest altitude plant species.
Geologists have subdivided the rocks comprising Mount Everest into three units called " formations". Each formation is separated from the other by low-angle faults, called “ detachments”, along which they have been thrust 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.
From its summit to the top of the Yellow Band, about 8,600 m (28,000 ft) above sea level, the top of Mount Everest consists of the Qomolangma Formation, which has also been designated as either the Everest Formation or Jolmo Lungama Formation. It consists of grayish to dark gray or white, parallel laminated and bedded, Ordovician limestone inter layered with subordinate beds of recrystallized dolomite with argillaceous laminae and siltstone. Gansser first reported finding microscopic fragments of crinoids in this limestone. 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 recrystallized 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 (300 ft) below the summit of Mount Everest, consists of sediments trapped, bound, and cemented by the biofilms of microorganisms, especially cyanobacteria, in shallow marine waters. The Qomolangma Formation is broken up by several high-angle faults that terminate at the low angle thrust fault, the Qomolangma Detachment. This detachment separates it from the underlying Yellow Band. The lower five meters of the Qomolangma Formation overlying this detachment are very highly deformed.
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 recrystallized crinoid ossicles. The upper five meters of the Yellow Band lying adjacent to the Qomolangma Detachment is badly deformed. A 5–40 cm (2–16 in) thick fault breccia separates it from the overlying Qomolangma Formation.
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 thrust fault called the "Lhotse detachment".
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). 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.
|Olympus Mons summit||0.03 kilopascals (0.0044 psi)|
|Mars average||0.6 kilopascals (0.087 psi)|
|Hellas Planitia bottom||1.16 kilopascals (0.168 psi)|
|Armstrong limit||6.25 kilopascals (0.906 psi)|
|Mount Everest summit||33.7 kilopascals (4.89 psi)|
|Earth sea level||101.3 kilopascals (14.69 psi)|
|Dead sea level||106.7 kilopascals (15.48 psi)|
Besides rubbish, the degradation on Himalayan peaks and other issues concerned long-time Everest guide and climber Apa Sherpa. He said when he first started climbing Everest, the trail to the summit was covered with ice and snow. But it is now dotted with bare rocks. The melting ice has also exposed deep crevasses, making expeditions more dangerous. Apa organized an expedition to remove 4,000 kg (8,800 lb) of rubbish from the lower part of the mountain and another 1,000 kg (2,200 lb) from higher areas.
In 2008, a new weather station at about 8000 m altitude (26,246 feet) went online. The station's first data in May 2008 were air temperature −17 °C, relative humidity 41.3%, atmospheric pressure 382.1 hPa (38.21 kPa), wind direction 262.8°, wind speed 12.8 m/s (28.6 mph), global solar radiation 711.9 watts/m2, solar UVA radiation 30.4 W/m2. The project was orchestrated by Stations at High Altitude for Research on the Environment (SHARE), who also placed the Mount Everest webcam in 2011. The weather station is located on the South Col and is solar powered.