According to Everest historians, expeditions to this mountain nowadays are very different from those in pioneer days when the teams numbered a dozen climbers supported by a few hundred porters carrying tons of equipment. The so-called sporting expeditions began in the 1970s. More modest, they take place today according to a fairly well-defined scenario in terms of its major stages. However, teams must be ready to adjust the scenario to take into account unforeseen events that may arise at any time: changing climatic conditions, difficulty acclimatizing, accidents on the mountain. The accounts of the expeditions to the top of Everest by the Nepalese face (south pass) state for most of the following major stages.
An expedition taking the Nepalese face of Mount Everest lasts several weeks. At the start of the season, the Sherpas set up the fixed ropes along the route on the mountain.
THE BASE CAMP
The ascent begins at the base camp (5,340 m), where all the equipment is transported on the backs of yaks and porters from one of the most dangerous airports in the world, Tenzing-Hillary Airport located in Lukla. Climbers spend some time at base camp to acclimatize as the material is transported in stages by altitude carriers from base camp to camp I at approximately 5,900 meters. During a ceremony attended by all the teams then present at the base camp, a lama invokes the gods of the mountain to attract their benefits on the teams who will attempt the summit.
THE KHUMBU ICEFALL
The climbers must first cross the Khumbu Icefall, considered by all to be the most dangerous stage of the entire ascent. The icefall rises for about 700 meters. The course is dotted with crevasses, some of which are 200 meters deep. A fixed rope installed by the Sherpas guides climbers through the seracs, immense unstable blocks of ice some of which can reach a height of 25 meters, which advance at the pace of the glacier and can detach themselves from it at any time. The climbers thus progress towards camp I.
The next stage takes place on the western valley which separates Camp I and Camp II, a valley of ice riddled with huge crevasses. To cross them, mountaineers make "bridges" by attaching aluminum ladders end to end. A risky maneuver because the climbers are wearing big crampons. The material is transported by the Sherpas to Camp II (6500 m) which becomes an advanced operational base. Over the days, provisions and equipment are gradually transported to the upper camps. After Camp II, the stage consists of crossing the face of Lhotse, a mountain close to Everest, a veritable wall of ice and rocks swept by the wind, in order to reach Camp III (7,200 m). It is then the climb to Camp IV established at the south pass at about 8,000 meters. Each camp constitutes an acclimatization stage. During their ascent, climbers often descend to a lower camp, sometimes even to base camp, to promote poor acclimatization.
THE FINAL ASSAULT
When the climbers are acclimatized, the teams monitor the weather conditions in order to take advantage of a window of good weather to give the final assault from Camp IV. This last stage begins with the glow of the headlamps in order to reach the top of the ridge around noon. As the sun rises, climbers reach a sharp ridge bordered by vertiginous precipices leading to the south pass at 8,750 m. A few meters to the left, an abyss of 2,400 meters plunges towards Nepal On the right, a cliff of 3,000 meters overlooks Tibet. Finally, 30 meters from the summit, stands the Hillary Step, a 12-meter rock that blocks access to the summit and which, according to experts, presents the greatest technical difficulty of the entire ascent.
Because of the exhaustion and inhospitality of the place, the roped parties never stay very long at the top (8,850 m). Usually no more than ten to fifteen minutes. Not only does the body no longer acclimatize to this altitude, but from 7600 meters (death zone), it began to wither away. The descent is considered more dangerous than the climb by most. Fatigue and poor acclimatization can lead to coordination problems. Another risk is the sudden onset of a storm. Moreover, 80% of fatal accidents on Everest would occur during the return.