Franck Chapon, mountain guide in Chamonix (Haute-Savoie) for 35 years, organizes ascents of Mont-Blanc. But with the very high temperatures of this month of July, he is forced to review his organization: “This forces us to leave much earlier and to do most of the big snow and ice races at night, to make the most of the most fragile temperatures.“. The weather forecast indicates temperatures close to 10 degrees for several days, at 3,800 meters. At this time, seasonal normals should be zero degrees.
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Two weeks after the drama of the Marmolada glacier, which killed at least eleven people at the beginning of the month in the Italian Alps, the prefecture of Haute-Savoie calls for vigilance on the normal access route to Mont-Blanc, known as “of the snack”. She is worried about the consequences of the drought that the department has been experiencing for several weeks.
Mont-Blanc has already experienced a heat wave during the heat wave of 2003. But this time, the big difference is that “the mountain has already suffered enormously from all the last heat waves“, details Ludovic Ravanel, geomorphologist at the Edytem laboratory of the University of Savoie. “In 2003, the high mountain was still in good condition“, he underlines. This year, on June 18, during the previous heat wave of 2022, 10.4 ° C were recorded at nearly 4,800 meters above sea level. Almost four degrees more than the previous record, which dates from 2019 and was 6.8°C.”We have a situation that is already very degraded with the approach of this new heatwave episode which promises to be quite long“, worries the specialist.
The union of high mountain guides has sent a prevention message to all of its members to make them aware of the risks of falling ice or stones. “Some peaks are more dangerous than others. The Aiguille du Goûter, we can see that it is dangerous. The Round Tower or even the access to the Dent du Géant now, it is an access particularly exposed to rockfall“, notes Christian Jacquet, vice-president of the union.
To monitor the evolution of the massif and try to prevent accidents, WhatsApp groups have been created. The guides have been trained in the warning signs of destabilization that they can communicate to the researcher, Ludovic Ravanel.
These signs can bewater flows“, emphasizes the scientist. Mont-Blanc is in poor condition. The permafrost, which serves as cement for the rock, is weakened by global warming. “We can translate the melting of the ice into the cracks. However, it is this ice which has a role of cement. We can also imagine rockfalls occurring in areas where previously nothing was happening.“, he observes.