Glaciers

Glaciers by Peter Thompson

A glacier is a river of ice moving slowly. Although a small block of ice may appear hard, and unable to “flow”, this is not the case for larger quantities of ice. When the ice gets to a thickness of about 25 metres it moves down hills by its own accord and bend and moves around anything in its path. Scientists call this movement “plastic flow” and it can only work as long as the ice moves slowly. If the ice moves to quickly it breaks. This property explains why when glaciers flow over a cirque, which is the bowl shape in a cliff formed by a previous glacier, they break up into crev...