Melting and therefore unstable, a glacier on the Italian side of Mont Blanc is being closely monitored by scientists. They fear that rising temperatures pose a threat to the valley.
It is the Planpincieux glacier, perched at an altitude of 2,700 meters above the town of the same name. It is located below the south face of the Grandes Jorasses.
Qualified as “temperate,” it is already melting, unlike polar glaciers still frozen in the rock layer. Which means the Planpincieux glacier can slide faster due to the layer of water it sits on, making it more dangerous for the Val Ferret below, experts say.
“We are facing a significant increase in temperatures, which accelerates the formation of the water layer under the glacier,” Valerio Segor, director of natural risk management in the Aosta Valley, in northwestern Italy, told AFPTV.
Previously, the thicker and less fractured Planpincieux glacier was in a more stable position on the rock, recalls Paolo Ferret, a glacier expert based in Courmayeur but, due to rising temperatures caused by climate change, ” it just moved on a smooth surface making it more unstable. “
The glacier slides slowly but surely, up to a meter and a half a day in extreme cases, he said, while the Whymper serac, a polar-type glacier that dominates it at an altitude of 4,000 meters, glides in a distance of 2 to 20 meters. centimeters each day.
A huge 15,000 m3 block of ice broke off the Whymper in October, just after authorities banned access to the trails below. The movements of the Planpincieux glacier and those above it are closely monitored by radar and the regional authorities have established emergency plans based on various scenarios.
The “extreme” scenario foresees the fall of 800,000 m3 of ice on the town and the access roads “but there is no guarantee that this will happen”, according to Paolo Ferret.