Mount Everest

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Mount Everest, also called Chomolungma or Qomolangma (Tibetan: ཇོ་མོ་གླང་མ) or Sagarmatha (Nepali: सगरमाथा) is the highest mountain on Earth, as measured by the height of its summit above sea level. The mountain, which is part of the Himalaya range in High Asia, is located on the border between Nepal and Tibet, China. By the end of the 2006 climbing season there had been 3,050 ascents to the summit by 2,062 individuals, and at least 630 more ascents in 2007.^{[citation needed]} There have been more than 200 deaths on the mountain, where conditions are so difficult that most corpses have been left where they fell; some are visible from standard climbing routes.^[4]

Climbers range from experienced mountaineers to relative novices who count on their paid guides to get them to the top. This means climbers are a significant source of tourist revenue for Nepal, whose government also requires all prospective climbers to obtain an expensive permit, costing up to $25,000 (USD) per person. ^[5]

[edit] Naming

The Tibetan name for Mount Everest is Chomolungma or Qomolangma (ཇོ་མོ་གླིང་མ, translated as "Mother of the Universe" or "Goddess Mother of the Earth"), and the related Chinese name is Zhūmùlǎngmǎ Fēng (simplified Chinese: 珠穆朗玛峰; traditional Chinese: 珠穆朗瑪峰) or Shèngmǔ Fēng (simplified Chinese: 圣母峰; traditional Chinese: 聖母峰).^{[citation needed]} According to English accounts of the mid-19th century, the local name in Darjeeling for Mount Everest was Deodungha, or "Holy Mountain." [1]. In the 1960s, the Government of Nepal gave the mountain the official Nepali name of Sagarmatha (सगरमाथा), meaning "Goddess of the Sky".^{[citation needed]}

In 1865, the mountain was given its English name by Andrew Waugh, the British surveyor-general of India. With both Nepal and Tibet closed to foreign travel, 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.

Waugh chose to name the mountain after George Everest, first using the spelling Mont Everest, and then Mount Everest. However, the modern pronunciation of Everest (IPA: /ˈɛvərɪst/ (EV-er-est)) is in fact different from Sir George's own pronunciation of his surname, which was /ˈiːvrɪst/ (EAVE-rest).^{[citation needed]}

In the late 19th century many European cartographers incorrectly believed that a native name for the mountain was "Gaurisankar".^[6] This was a result of confusion of Mount Everest with the actual Gauri Sankar, which, when viewed from Kathmandu, stands almost directly in front of Everest.^{[citation needed]}

In the early 1960s, the Nepalese government realized that Mount Everest had no Nepalese name.^{[citation needed]} This was because the mountain was not known and named in ethnic Nepal (that is, the Kathmandu valley and surrounding areas).^{[citation needed]} The government set out to find a name for the mountain (the Sherpa/Tibetan name Chomolangma was not acceptable, as it would have been against the idea of unification (Nepalization) of the country. The name Sagarmatha (सगरमाथा) was thus invented by Baburam Acharya.^{[citation needed]}

In 2002, the Chinese People's Daily newspaper published an article making a case against the continued use of the English name for the mountain in the Western world, insisting that it should be referred to by its Tibetan name. The newspaper argued that the Chinese (in nature a Tibetan) name preceded the English one, as Mount Qomolangma was marked on a Chinese map more than 280 years ago.^[7]

[edit] Measurement

Radhanath Sikdar, an Indian mathematician and surveyor from Bengal, was the first to identify Everest as the world's highest peak in 1852, using trigonometric calculations based on measurements of "Peak XV" (as it was then known) made with theodolites from 240 km (150 miles) away as part of the Great Trigonometric Survey of India. Measurement could not be made from closer due to a lack of access to Nepal. Peak XV was found to be exactly 29,000 feet (8,839 m) high, but was publicly declared to be 29,002 feet (8,840 m). The arbitrary addition of 2 feet (0.6 m) was to avoid the impression that an exact height of 29,000 feet was nothing more than a rounded estimate.

More recently, the mountain has been found to be 8,848 m (29,028 feet) high, although there is some variation in the measurements. The mountain K2 comes in second at 8,611 m (28,251 ft) high. On May 22, 2005, the People's Republic of China's Everest Expedition Team ascended to the top of the mountain. After several months' complicated measurement and calculation, on October 9, 2005, the PRC's State Bureau of Surveying and Mapping officially announced the height of Everest as 8,844.43 m ± 0.21 m (29,017.16 ± 0.69 ft). They claimed it was the most accurate measurement to date.^[8] But this new height is based on the actual highest point of rock and not on the snow and ice that sits on top of that rock on the summit, so, in keeping with the practice used on Mont Blanc and Khan Tangiri Shyngy, it is not shown here. The Chinese also measured a snow/ice depth of 3.5 m,^[9] which implies agreement with a net elevation of 8,848 m. But in reality the snow and ice thickness varies, making a definitive height of the snow cap, and hence the precise height attained by summiteers without sophisticated GPS, impossible to determine.

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.^[10] 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.^[11] Although it has not been officially recognized by Nepal,^[12] 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.^[13]

It is thought that the plate tectonics of the area are adding to the height and moving the summit north-eastwards. Two accounts^[11][14] suggest the rates of change are 4 mm per year (upwards) and 3-6 mm per year (northeastwards), but another account mentions more lateral movement (27 mm),^[15] and even shrinkage has been suggested.^[16]

The Mount Everest region, and the Himalayas in general, are thought to be experiencing ice-melt due to global warming.^[17] The exceptionally heavy southwest summer monsoon of 2005 is consistent with continued warming and augmented convective uplift on the Tibetan plateau to the north.^{[citation needed]}

[edit] Comparisons

Everest is the mountain whose summit attains 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;^[18] 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^[18] to summit, Denali, in Alaska, is also taller than Everest. Despite its height above sea level of only 6,193.6 m (20,320 ft), Denali sits atop a sloping plain with elevations from 300-900 m (1,000-3,000 ft), yielding a height above base in the range of 5,300-5,900 m (17,300-19,300 ft); a commonly quoted figure is 5,600 m (18,400 ft).^[19] 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 m (12,000 ft) to 4,650 m (15,300 ft).^[13].

The summit of Chimborazo in Ecuador is 2,168 m (7,113 ft) farther from the Earth's centre (6,384.4 km or 3,967.1 mi) than that of Everest (6,382.3 km or 3,965.8 mi), because the Earth bulges at the Equator. However, Chimborazo attains a height of only 6,267 m (20,561 ft) above sea level, and by this criterion it is not even the highest peak of the Andes.

The deepest spot in the ocean is deeper than Everest is high: the Challenger Deep off the Mariana Islands, is so deep that if Everest could be placed into it there would be more^{[citation needed]} than 2 km (more than 1.3 mi) of water covering it.

[edit] Climbing routes

<imagemap> Image:Himalaya_annotated.jpg|thumb|250px|right|Southern and northern climbing routes as seen from the International Space Station. rect 58 14 160 49 Chomo Lonzo rect 200 28 335 52 Makalu rect 378 24 566 45 Mount Everest rect 188 581 920 656 Tibetan Plateau rect 250 406 340 427 Rong River rect 333 149 409 186 Changtse rect 550 284 677 303 Rongbuk Glacier rect 478 196 570 218 North Face rect 237 231 346 267 East Rongbuk Glacier rect 314 290 536 309 North Col north ridge route rect 531 79 663 105 Lhotse rect 582 112 711 130 Nuptse rect 603 232 733 254 South Col route rect 716 165 839 206 Gyachung Kang rect 882 147 967 183 Cho Oyu rect 1 1 999 661 Press button (bottom right) to enlarge image

desc bottom-left </imagemap>

Mt. Everest has two main climbing routes, the southeast ridge from Nepal and the northeast 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 recognised 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 foreigners in 1949. Reinhold Messner (Italy) summited the mountain solo for the first time, without supplementary oxygen or support, on the more difficult Northwest route via the North Col to the North Face and the Great Couloir, on August 20 1980. He climbed for three days entirely alone from his base camp at 6500 meters. This route has been noted as the 8th climbing route to the summit.

Most attempts are made during May before the summer monsoon season. A change in the jet stream at this time of year reduces the average wind speeds high on the mountain. While attempts are sometimes made after the monsoons in September and October, the additional snow deposited by the monsoons and the less stable weather patterns makes climbing more difficult.

[edit] Southeast ridge

The ascent via the southeast ridge begins with a trek to Base Camp at 5,380 m (17,600 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 hybrids) and human porters to Base Camp on the Khumbu Glacier. When Hillary and Tenzing climbed Everest in 1953, they started from 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 m (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 relatively 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 metres 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 a 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 metres 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 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 metres above) within 10 to 12 hours. Climbers will first reach "The Balcony" at 8,400 m (27,700 ft), a small platform where they can rest and gaze at peaks to the south and east in the early dawn light. 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 (28,750 ft).

Hillary and Tenzing were the first climbers to ascend this step and they did it with primitive ice climbing equipment and without fixed 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 very large cornices of snow. After the Hillary Step, climbers also must traverse a very loose and rocky section that has a very large entanglement of fixed ropes that can be troublesome in bad weather. Climbers will typically spend less than a half-hour on "top of the world" as they realize the need to descend to Camp IV before darkness sets in, afternoon weather becomes a serious problem, or supplemental oxygen tanks run out.

[edit] Northeast ridge

The northeast 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 (17,000 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 goes up the north face through a series of gullies and steepens into downsloping slabby terrain before reaching the site of Camp VI at 8,230 m (27,000 ft). From Camp VI, climbers will make their final summit push. Climbers must first make their way through three rock bands known as First Step: 27,890 feet - 28,000 feet, Second Step: 28,140 feet - 28,300 feet, and Third Step: 28,510 feet - 28,870 feet. Once above these steps, the final summit slopes (50 to 60 degrees) to the top.

China is paving a 130-km (66-mile) dirt road from Tingri County to its Base Camp in order to accommodate growing numbers of climbers on their side of the mountain. It will become the highest asphalt-paved road in the world. Construction began on June 18, 2007, at a cost of 150 million yuan (US$19.7 million). China also plans on routing the 2008 Olympic Torch Relay over Everest, going up the South Col route and back down the North Col route, on the way to the 2008 Summer Olympics in Beijing.^[20]

[edit] Ascents

Main article: Timeline of climbing Mount Everest

[edit] Early expeditions

In 1885, Clinton Thomas Dent, president of the Alpine Club, suggests that climbing Mount Everest is possible in his book Above the Snow Line.^[21]

On June 8, 1924, George Mallory and Andrew Irvine, both of the United Kingdom, made an attempt on the summit via the north col/north ridge route from which they never returned.

In 1999, the Mallory and Irvine Research Expedition found Mallory's body in the predicted search area near the old Chinese camp. Controversy has raged in the mountaineering community as to whether the duo may have summited 29 years before the confirmed ascent (and of course, safe descent) of Everest by Sir Edmund Hillary and Tenzing Norgay in 1953. The general consensus among climbers has been that they did not.

Mallory had gone on a speaking tour of the United States the year before in 1923; it was then that he exasperatedly gave the famous reply, "Because it is there," to a New York journalist in response to hearing the question, "Why climb Everest?" for seemingly the thousandth time. Comprehensive information is available at Mallory and Irvine: The Final Chapter including critical opposing viewpoints.

In 1933, Lady Houston, a British millionaire ex-showgirl, 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 ascended the mountain from Tibet, via the north face. However, this access was closed to western expeditions in 1950, after the Chinese reasserted control over Tibet. However, 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.

[edit] 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 300 feet of the summit on 26 May, but turned back after becoming exhausted. The next day, the expedition made its second and final assault on the summit with its second climbing pair. The summit was eventually reached at 11:30 a.m. local time on May 29, 1953 by the New Zealander Edmund Hillary and Sherpa Tenzing Norgay from Nepal climbing 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.^[22] 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. Returning to Kathmandu a few days later, Hillary and Hunt discovered that they had been promptly knighted in the Order of the British Empire for their efforts. Hunt was ultimately made a life peer in Britain, while Hillary became a founding member of the Order of New Zealand. Tenzing was granted the George Medal for his efforts.

[edit] 1996 disaster

See Main articles: 1996 Everest Disaster.

During the 1996 climbing season, fifteen people died trying to come down from the summit, making it the deadliest single year in Everest history. Eight of them died on May 11 alone. The disaster gained wide publicity and raised questions about the commercialization of 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 large 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 May 11 suggested that freak weather caused oxygen levels to plunge by around 14%.^[23][24]

The storm's impact on climbers on the mountain's other side, the North Ridge, 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.

[edit] 2003 - 50th Anniversary of First Ascent

2003 marked the 50th anniversary of the first ascent, and a record number of teams, including some very distinguished climbers, climbed or attempted to climb the mountain.

[edit] 2005 - Helicopter landing

On 14 May 2005, pilot Didier Delsalle of France landed a Eurocopter AS 350 B3 helicopter on the summit of Mount Everest^[25] (without any witness) and took off after about four minutes. (His rotors were continually engaged, constituting a "hover landing", and avoiding the risks of relying on the snow to support the aircraft.) He thereby set rotorcraft world records, for highest of both landing (de facto) and take-off (formally).^[26]

Delsalle had also performed, two days earlier, a take-off from the South Col; some press reports suggested^{[citation needed]} that the report of the summit landing was a misunderstanding of a South Col one.

[edit] 2006 - North Face ski descent

On 16 May 2006, adventurers Tormod Granheim and Tomas Olsson skied the Norton Couloir from the summit to the North Col. During the descent Olsson fell an estimated 1700 meters to his death.

[edit] 2006 - David Sharp controversy

Double-amputee climber Mark Inglis revealed in an interview with the press on May 23, 2006, that his climbing party, and many others, had passed a distressed climber, David Sharp, on May 15, sheltering under a rock overhang 450 meters below the summit, without attempting a rescue. The revelation sparked wide debate on climbing ethics, especially as applied to Everest. The climbers who left him said that the rescue efforts would be useless and only cause more deaths because of how many people it would have taken to pull him off.

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, and Sharp had chosen to climb solo without any support, so he did not identify himself to other climbers. The base camp manager assumes that Sharp is part of a group that has abandoned him, and informs his climber that there is no chance of him being able to help Sharp [at 8000+ meters in altitude, barely anyone has the strength to help another man who is only semi conscious, and Max Chaya is only an amateur mountaineer]. 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 frost-bite, 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 forgo all support leaves him with no margin for recovery.

As this debate raged, on May 26, 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 May 21, 2007, when Canadian climber Meagan McGrath initiated the successful high-altitude rescue of Nepali Usha Bista.

[edit] Death zone

Main article: Death zone

While conditions for any area classified as a death zone apply to Mount Everest (altitudes higher than 8,000 m/26,246 ft), it is significantly more difficult for a climber to survive at the death zone on Mount Everest. Temperatures can dip to very low levels, resulting in frostbite of any body part exposed to the air. Because temperatures are so low, snow is well-frozen in certain areas and death by slipping and falling can also occur. High winds at these altitudes on Everest are also a potential threat to climbers. The atmospheric pressure at the top of Everest is about a third of sea level pressure, meaning there is about a third as much oxygen available to breathe as at sea level.^[27]

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 level of available oxygen had direct effect on blood oxygen saturation levels. At sea level these are usually 98% to 99%, but at base camp this fell to between 85% and 87%. Blood samples taken at the summit indicated very low levels of oxygen present. A side effect of this is a vastly increased breathing rate, from 20--30^{[citation needed]} breaths per minute to 80--90 breaths, leading to exhaustion just trying to breathe.

Lack of oxygen, exhaustion, extreme cold and the dangers of the climb all contribute to the death toll.

One death-dealing phenomenon, however, does not plague climbers — lightning. Lightning does not strike Mount Everest. NASA's lightning detection system does record significant lightning in the Tibet plateau, up to about 7,000 feet. But none along the high Tibetan mountains.^[28]

[edit] Bottled oxygen controversy

Most expeditions use oxygen masks and tanks^[29] above 8,000 m (26,246 ft). Everest can be climbed without supplementary oxygen but this increases the risk to the climber. Humans do not think clearly with low oxygen, and the combination of severe weather, low temperatures, and steep slopes often require quick, accurate decisions.

The use of bottled oxygen to ascend Mount Everest has been controversial. George Mallory himself described the use of such oxygen as unsportsmanlike, but he later concluded that it would be impossible to summit without it and consequently used it. ^[30] When Tenzing and Hillary made the first successful summit in 1953 they used bottled oxygen. 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, without supplemental oxygen or support, on the more difficult northwest route, in 1980. In the aftermath of Messner's two successful ascents, the debate on bottled oxygen usage continued.

The aftermath of the 1996 Mount Everest 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 May 10 disaster was partially caused by the sheer number of climbers (33 on that day) attempting to ascend, causing bottlenecks at the Hillary Step and delaying many climbers, most of whom summited 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.^[31] 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.^[32] Krakauer and his supporters point out that, without bottled oxygen, Boukreev was unable to directly help his clients descend.^[33] They state that Boukreev said that he was going down with client Martin Adams,^[33] but when Adams slowed down^{[citation needed]}, Boukreev later descended faster and left him behind.^[33]

[edit] Life-threatening thefts

Other 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.^[34] The climbers who left him said that the rescue efforts would be useless and only cause more deaths because of how many people it would have taken to pull him off.

[edit] Flora and fauna

Euophrys omnisuperstes, a minute black jumping spider, has been found at elevations as high as 6,700 meters, possibly making it the highest confirmed permanent resident on Earth. They lurk in crevices and possibly 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 (7,920 m),^[35] scavenging on food, or even corpses, left over by climbing expeditions.

[edit] Geology

Geologists^[36][37] have subdivided the rocks comprising Mount Everest into three units called “formations”. Each of these formations are separated from each 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 Fomation, the North Col Formation, and the Rongbuk Formation.

From its summit to the top of the Yellow Band, about 8,600 m above sea level, the top of Mount Everest consists of the Qomolangma Fomation, 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 limestone interlayered with subordinate beds of recrystallized dolomite with argillaceous laminae and siltstone. Gansser^[38] reported finding visible fragments of crinoids in these limestones. Petrographic analysis of samples of this Ordovician limestone from near the summit revealed them to be composed of carbonate pellets and finely fragmented remains of trilobites, crinoids, and ostracods. 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 metres of the Qomolangma Formation overlying this detachment are very highly deformed.^[39][40]

The bulk of Mount Everest, between 7,000 and 8,600 m, consists of the North Col Formation, of which the Yellow Band forms its upper part between 8,200 to 8,600 m. The Yellow Band consists of intercalated beds of diopsite-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 found it to consist as much as five percent of the ghosts of recrystallized crinoid ossicles. The upper five metres of the Yellow Band lying adjacent to the Qomolangma Detachment is badly deformed. A 5–40 cm thick fault breccia separates it from the overlying Qomolangma Formation.^[41][42]

The remainder of the North Col Formation, exposed between 7,000 to 8,200 m on Mount Everest, consists of interlayered and deformed schist, phyllite, and minor marble. Between 7,600 and 8,200 m, 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, 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 the result of the metamorphism of 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”.^[43][44]

Below 7,000 m, the Rongbuk Formation underlies the North Col Formation and forms the base of Mount Everest. It consists of sillminite-K-feldspar grade schist and gneiss intruded by numerous sills and dikes of leucogranite ranging in thickness from one cm to 1,500 m. ^[45][46]

[edit] See also

• Highest mountains of the world
• North Col
• South Col
• Rongbuk Glacier
• Rongbuk Monastery
• Kangshung Face, Mount Everest
• Geography of China
• Sagarmatha National Park
• Geology of the Himalaya
• List of deaths on eight-thousanders

[edit] Image gallery

[edit] External links

• National Geographic site on Mt. Everest
• NOVA site on Mt. Everest
• Royal Geographical Society site on Mt. Everest
• Mount Everest panorama, Mount Everest interactive panorama (Quicktime format), Virtual panoramas *North *South
• Interactive climb of Everest from Discovery Channel
• Google Maps satellite image, Mount Everest Basecamp with Google Earth (KMZ file)
• Mount Everest on Summitpost
• The Rest of Everest video podcast
• Full list of all 3,050 ascents of Everest up to and including 2006, and 630 ascents in 2007 (in Excel format)
• The Everest Trek guidebook
• Everest Base Camp Clinic

[edit] References

• Summits and deaths per year
• American Alpine Journal 2005, p. 393.

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