Difficulties

The difficulties of climbing Mount Everest are legendary. Massive snow and ice avalanches are a constant threat to all expeditions. The avalanches thunder off the peaks repeatedly, sometimes burying valleys, glaciers, and climbing routes. Camps are chosen to avoid known avalanche paths, and climbers who make ascents through avalanche terrain try to cross at times when the weather is most appropriate. Hurricane-force winds are a well-known hazard on Everest, and many people have been endangered or killed when their tents collapsed or were ripped to shreds by the gales. Hypothermia, the dramatic loss of body heat, is also a major and debilitating problem in this region of high winds and low temperatures.

Another hazard facing Everest climbers is the famous Khumbu icefall, which is located not far above Base Camp and is caused by the rapid movement of the Khumbu glacier over the steep rock underneath. The movement breaks the ice into sérac (large, pointed masses of ice) cliffs and columns separated by huge crevasses, and causes repeated icefalls across the route between Base Camp and Camp I. Many people have died in this area. Exposed crevasses may be easy to avoid, but those buried under snow can form treacherous snow bridges through which unwary climbers can fall.

The standard climb of Mount Everest from the south side ascends the Khumbu glacier to Base Camp at 5,400 m (17,600 ft). Typical expeditions use four camps above Base Camp; these camps give the climbers an opportunity to rest and acclimate (adapt) to the high altitude. The route from Base Camp through the great Khumbu icefall up to Camp I at 5,900 m (19,500 ft) is difficult and dangerous; it usually takes one to three weeks to establish because supplies must be carried up the mountain in several separate trips. Once Camp II, at 6,500 m (21,300 ft), has been supplied in the same manner using both Base Camp and Camp I as bases, climbers typically break down Base Camp and make the trek from there to Camp II in one continuous effort. Once acclimatized, the climbers can make the move to Camp II in five to six hours. Camp III is then established near the cirque of the Khumbu glacier at 7,300 m (24,000 ft). The route up the cirque headwall from Camp III to the South Col and Camp IV at 7,900 m (26,000 ft) is highly strenuous and takes about four to eight hours. The South Col is a cold, windy, and desolate place of rocks, snow slabs, littered empty oxygen bottles, and other trash