A big rock looks set to come down on the Aletsch glacier in Valais. Geologists are alarmed, but no one can tell how and when exactly it will break. (RTS/swissinfo.ch)
At 30km long, the Aletsch glacier is the largest in the Alps. It has shrunk significantly over the past decades as a result of global warming. In some places, where the glacier used to support the surrounding mountains, the ice has almost completely disappeared. This greatly increases the risk of rockslides.
Now geologists have discovered major cracks on one of the mountain faces. It is moving 20 centimetres every day. The experts don’t know how soon the mountain face will slide nor how exactly it will come down. The rockslide doesn’t pose an imminent threat to people, since no one lives inside the danger zone. Hiking routes have been closed off and marked with warning signs.
According to Valais geologist Raphaël Mayoraz, the mountain rubble could form a dam between the glacier and the Valais. This could result in the formation of a lake, which could pose a potential threat to people.