Pfad der Pioniere 09: Naturgewalten

Some rocks seem to be made to last. But the impression is deceiving: rocks are subject to constant change. Cold, heat, water and ice take their toll on them and plant roots penetrate into small cracks. Without warning, a boulder can suddenly come loose from the rock face. At a speed of around 100 km per hour, the stone races down the slope and bounces high into the air like a rubber ball. Only when it flattens out or when there are many trees in the way does the stone come to a standstill. Where rockfall is frequent, unvegetated scree slopes form. They are the breeding ground for debris flows (item 2).