A glacier is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as crevasses and seracs, as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques, moraines, or fjords. Although a glacier may flow into a body of water, it forms only on land and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water.
The Sherpas are one of the Tibetan ethnic groups native to the most mountainous regions of Nepal and Tibetan Autonomous Region. The term sherpa or sherwa derives from the Tibetan-language words ཤར shar ('east') and པ pa ('people'), which refer to their geographical origin in eastern Tibet.
The Mer de Glace is a valley glacier located on the northern slopes of the Mont Blanc massif, in the French Alps. It is 7.5 km long and 200 metres (660 ft) deep but, when all its tributary glaciers are taken into account, it can be regarded as the longest and largest glacier in France, and the second longest in the Alps after the Aletsch Glacier.
I can no otherwise convey to you an image of this body of ice, broken into irregular ridges and deep chasms than by comparing it to waves instantaneously frozen in the midst of a violent storm.
A crevasse is a deep crack that forms in a glacier or ice sheet. Crevasses form as a result of the movement and resulting stress associated with the shear stress generated when two semi-rigid pieces above a plastic substrate have different rates of movement. The resulting intensity of the shear stress causes a breakage along the faces.
Glacial motion is the motion of glaciers, which can be likened to rivers of ice. It has played an important role in sculpting many landscapes. Most lakes in the world occupy basins scoured out by glaciers. Glacial motion can be fast or slow, but is typically around 25 centimetres per day (9.8 in/d).
The Khumbu Icefall is located at the head of the Khumbu Glacier and the foot of the Western Cwm, which lies at an elevation of 5,486 metres (17,999 ft) on the Nepali slopes of Mount Everest, not far above Base Camp and southwest of the summit. The icefall is considered one of the most dangerous stages of the South Col route to Everest's summit.
A serac is a block or column of glacial ice, often formed by intersecting crevasses on a glacier. Commonly house-sized or larger, they are dangerous to mountaineers, since they may topple with little warning. Even when stabilized by persistent cold weather, they can be an impediment to glacier travel.
A bergschrund is a crevasse that forms where moving glacier ice separates from the stagnant ice or firn above. It is often a serious obstacle for mountaineers, who sometimes abbreviate "bergschrund" to "schrund". Bergschrunds extend to the bedrock and can have a depth of well over 100 metres (330 ft).
An ice stream is a region of fast-moving ice within an ice sheet. It is a type of glacier, a body of ice that moves under its own weight. They can move upwards of 1,000 metres (3,300 ft) a year, and can be up to 50 kilometres (31 mi) in width, and hundreds of kilometers in length. They tend to be about 2 km (1.2 mi) deep at the thickest, and constitute the majority of the ice that leaves the sheet. In Antarctica, the ice streams account for approximately 90% of the sheet's mass loss per year, and approximately 50% of the mass loss in Greenland.
The Man Who Skied Down Everest is a Canadian documentary about Yuichiro Miura, a Japanese alpinist who skied down Mount Everest in 1970. The film was produced by Crawley Films' "Budge" Crawley and directed by Crawley and Bruce Nyznik.
There are two base camps on Mount Everest, on opposite sides of the mountains: South Base Camp is in Nepal at an altitude of 5,364 metres (17,598 ft), while North Base Camp is in China at 5,150 metres (16,900 ft).
The Erebus Glacier Tongue is a mountain outlet glacier and the seaward extension of Erebus Glacier from Ross Island. It projects 11 kilometres (6.8 mi) into McMurdo Sound from the Ross Island coastline near Cape Evans, Antarctica. The glacier tongue varies in thickness from 50 metres (160 ft) at the snout to 300 metres (980 ft) at the point where it is grounded on the shoreline. Explorers from Robert F. Scott's Discovery Expedition (1901–1904) named and charted the glacier tongue.
Blue Glacier is a large glacier located to the north of Mount Olympus in the Olympic Mountains of Washington. The glacier covers an area of 1.7 sq mi (4.4 km2) and contains 580,000,000 cu ft (16,000,000 m3) of ice and snow in spite of its low terminus elevation. The glacier length has decreased from about 3.4 mi (5.5 km) in 1800 to 2.7 mi (4.3 km) in the year 2000. Just in the period from 1995 and 2006, Blue Glacier retreated 325 ft (99 m). Blue Glacier is also thinning as it retreats and between 1987 and 2009 the glacier lost 178 ft (54 m) of its depth near its terminus and between 32 and 48 ft in the uppermost sections of the glacier known as the accumulation zone.
A supraglacial lake is any pond of liquid water on the top of a glacier. Although these pools are ephemeral, they may reach kilometers in diameter and be several meters deep. They may last for months or even decades at a time, but can empty in the course of hours.
Ice sheet dynamics describe the motion within large bodies of ice such as those currently on Greenland and Antarctica. Ice motion is dominated by the movement of glaciers, whose gravity-driven activity is controlled by two main variable factors: the temperature and the strength of their bases. A number of processes alter these two factors, resulting in cyclic surges of activity interspersed with longer periods of inactivity, on both hourly and centennial time scales. Ice-sheet dynamics are of interest in modelling future sea level rise.
Overdeepening is a characteristic of basins and valleys eroded by glaciers. An overdeepened valley profile is often eroded to depths which are hundreds of metres below the lowest continuous surface line along a valley or watercourse. This phenomenon is observed under modern day glaciers, in salt-water fjords and fresh-water lakes remaining after glaciers melt, as well as in tunnel valleys which are partially or totally filled with sediment. When the channel produced by a glacier is filled with debris, the subsurface geomorphic structure is found to be erosionally cut into bedrock and subsequently filled by sediments. These overdeepened cuts into bedrock structures can reach a depth of several hundred metres below the valley floor.
On 18 April 2014, seracs on the western spur of Mount Everest failed, resulting in an ice avalanche that killed sixteen climbing Sherpas in the Khumbu Icefall. This was the same icefall where the 1970 Mount Everest disaster had taken place. Thirteen bodies were recovered within two days, while the remaining three were never recovered due to the great danger in attempting such an expedition. Many Sherpas were angered by what they saw as the Nepalese government's meager offer of compensation to victims' families, and threatened a protest or strike. On 22 April, the Sherpas announced they would not work on Everest for the remainder of 2014 as a mark of respect for the victims.
Lingtren, 6,749 metres (22,142 ft), is a mountain in the Mahalangur Himal area of Himalaya, about 8 kilometres (5.0 mi) distant in a direct line from Mount Everest. It lies on the international border between Nepal and the Tibet Autonomous Region of China and it was first climbed in 1935. A mountain nearby to the west was originally named Lingtrennup but is now more commonly called Xi Lingchain.
The 1951 British Mount Everest reconnaissance expedition ran between 27 August 1951 and 21 November 1951 with Eric Shipton as leader.
A fissure is a long, narrow crack opening along the surface of Earth. The term is derived from the Latin word fissura, which means 'cleft' or 'crack'. Fissures emerge in Earth's crust, on ice sheets and glaciers, and on volcanoes.
