Rock glacier

Rock glaciers are composed of ice mixed with rock debris. They move very slowly. For example, the rock glacier of St Anne moves about 0.34m per year. We can distinguish 3 layers which form the rock glaciers. The top layer is formed of rocky debris, free of ice. This layer, in direct contact with the air, freezes in winter and melts in summer. The core layer is a mixture of ice and debris. The last layer is the rock debris buried by the moving glacier. Here, the rock glacier is covered with the first snowfall.