Mount Everest, also called Sagarmatha (Nepali: सगरमाथा meaning Head of the Sky) or Chomolungma, Qomolangma or Zhumulangma (in Tibetan: ཇོ་མོ་གླང་མ, in Chinese: 珠穆朗玛峰 Zhūmùlǎngmǎ Fēng) is the highest mountain on Earth, as measured by the height of its summit above sea level, which is 8,848 metres (29,029 ft). The mountain, which is part of the Himalaya range in High Asia, is located on the border between Sagarmatha Zone, Nepal, and Tibet, China.
In 1856, the Great Trigonometric Survey of India established the first published height of Everest at 29,002 ft (8,840 m), although at the time Everest was known as Peak XV. In 1865, Everest was given its official English name by the Royal Geographical Society upon recommendation of Andrew Waugh, the British Surveyor General of India at the time. Waugh was unable to propose an established local name due to Nepal and Tibet being closed to foreigners at the time, although Chomolungma had been in common use by Tibetans for centuries.
The highest mountain in the world attracts climbers of all levels, from well experienced mountaineers to novice climbers willing to pay substantial sums to professional mountain guides to complete a successful climb. The mountain, while not posing substantial technical climbing difficulty on the standard route (other eight-thousanders such as K2 or Nanga Parbat are much more difficult), still has many inherent dangers such as altitude sickness, weather and wind. By the end of the 2007 climbing season, there had been 3,679 ascents to the summit by 2,436 individuals. 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 US$25,000 per person.[4] Everest has claimed 210 lives, including eight who perished during a 1996 storm high on the mountain. Conditions are so difficult in the death zone that most corpses have been left where they fell, some of which are visible from standard climbing routes.[5]
Discovery of the highest mountain
In 1808, 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 gradually moved northward using giant 1100 pound (500 kg) theodolites (each requiring 12 men to carry) to measure heights as accurately as possible. They reached the Himalayan foothills by the 1830s, but Nepal was unwilling to allow the British to enter the country due to suspicions of political aggression and possible annexation. Several requests by the surveyors to enter Nepal were turned down.[6]
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 due to torrential rains and malaria — three survey officers died from malaria while two others had to retire due to failing health.[6]
Nonetheless, in 1847, the British pressed on and began detailed observations of the Himalayan peaks from observation stations up to 150 mi (240 km) away. Weather restricted work to the last three months of the year. In November 1847, Andrew Waugh, the British Surveyor General of India made a number of observations from Sawajpore station located in the eastern end of the Himalayas. At the time, Kangchenjunga was considered the highest peak in the world, and with interest he noted a peak beyond it, some 140 mi (230 km) away. John Armstrong, one of Waugh's officials, also saw the peak from a location further west and called it peak 'b'. Waugh would later write that the observations indicated that peak 'b' was higher than Kangchenjunga, but due to 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.[6]
In 1849, Waugh dispatched James Nicolson to the area. Nicolson was able to make two observations from Jirol, 118 mi (190 km) away. Nicolson then took the largest theodolite and headed east, obtaining over 30 observations from five different locations, with the closest being 108 mi (174 km) away from the peak.[6]
Nicolson retreated to Patna on the Ganges to perform the necessary calculations based on his observations. His raw data gave an average height of 30,200 ft (9,200 m) for peak 'b', but this did not take into account light refraction which distorts heights. The number clearly indicated, however, that peak 'b' was higher than Kangchenjunga. Unfortunately, Nicolson came down with malaria and was forced to return home, calculations unfinished. 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.[6]
Sagarmatha (Mount Everest) as seen from Kala PattarIn 1852, stationed at the survey's 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.[7] 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".[6] Peak XV was found to be exactly 29,000 feet (8,839 m) high, but was publicly declared to be 29,002 ft (8,840 m). The arbitrary addition of 2 feet (60 cm) was to avoid the impression that an exact height of 29,000 feet was nothing more than a rounded estimate.[8]
With the height now established, what to name the peak was clearly the next challenge. While the survey was anxious to preserve local names if possible (e.g., Kangchenjunga and Dhaulagiri were local names), Waugh argued that he was unable to find any commonly used local name. Waugh's search for a local name was hampered by Nepal and Tibet being closed to foreigners at the time. Many local names existed, with perhaps the best known in Tibet for several centuries being Chomolungma, which had appeared on a 1733 map published in Paris by the French geographer D'Anville. However, Waugh argued that with the plethora of local names, it would be difficult to favour one specific name over all others. So, he decided that Peak XV should be named after George Everest, his predecessor as Surveyor General of India.[6][9] 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.[10]
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.[6]
Naming
The Tibetan name for Mount Everest is Chomolungma or Qomolangma (ཇོ་མོ་གླིང་མ, which means "Saint Mother"), and the Chinese transliteration is Zhūmùlǎngmǎ Fēng (simplified Chinese: 珠穆朗玛峰; traditional Chinese: 珠穆朗瑪峰), which refers to Earth Mother; the Chinese translation is Shèngmǔ Fēng (simplified Chinese: 圣母峰; traditional Chinese: 聖母峰), which refers to Holy Mother. According to English accounts of the mid-19th century, the local name in Darjeeling for Mount Everest was Deodungha, or "Holy Mountain".[11]
In 1865, the mountain was officially given its English name by the Royal Geographical Society after being proposed by Andrew Waugh, the British Surveyor General of India.[6] 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, ˈɛvrɪst/[12] is in fact different from Sir George's own pronunciation of his surname, which was /ˈiːvrɪst/[13].
In the late 19th century, many European cartographers incorrectly believed that a native name for the mountain was "Gaurisankar".[14] 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 gave Mount Everest the official name Sagarmatha (सगरमाथा).[15] This name had not previously been used; the local inhabitants knew the mountain as Chomolungma. 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 Nepalese name for the mountain because the Sherpa/Tibetan name Chomolangma was not acceptable, as it would have been against the idea of unification (Nepalization) of the country.[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.[16]
Measurement
In 1856, Andrew Waugh announced Everest (then known as Peak XV) as 29,002 feet (8,840 m) high, after several years of calculations based on observations made by the Great Trigonometric Survey.
More recently, the mountain has been found to be 8,848 metres (29,029 ft) high, although there is some variation in the measurements. On 9 October 2005, after several months of measurement and calculation, 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 and precise measurement to date.[17] 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,[18] which is in agreement with a net elevation of 8,848 m. The snow and ice thickness varies over time, making a definitive height of the snow cap 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.[19] 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.[20] Although it has not been officially recognized by Nepal,[21] 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.[22]
It is thought that the plate tectonics of the area are adding to the height and moving the summit north-eastwards. Two accounts[20][23] suggest the rates of change are 4 mm (0.16 in) per year (upwards) and 3-6 mm (0.12-0.25 in) per year (northeastwards), but another account mentions more lateral movement (27 mm/1.1 in),[24] and even shrinkage has been suggested.[25]
The Mount Everest region, and the Himalayas in general, are thought to be experiencing ice-melt due to global warming.[26]
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;[27] 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[27] 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 300-900 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).[28] 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).[22]
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.
Climbing routes
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.[29] 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.[29] This was, however, a route decision dictated more by politics than by design as the Chinese border was closed to the western world in 1950s after the Communist China took over the control Tibet from the Republic of China.[30]
View from space showing South Col route and North Col/Ridge routeMost 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.[31][32] 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 more difficult.
Southeast ridge
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 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 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 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.[33]
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.[33]
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 (27,600 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.
[33]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).
[33]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. 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 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.
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 (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: 27,890 feet - 28,000 feet, to the crux of the climb, the Second Step: 28,140 feet - 28,300 feet. (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 is used by virtually all climbers on the route.) Once above the Second Step the inconsequential Third Step is clambered over: 28,510 feet - 28,870 feet. Once above these steps, the summit pyramid is climbed by means of a snow slope of 50 degrees, to the final summit ridge along which the top is reached.[34]
