Chapter 28, Problem 15TE

To determine

The reason of formation of crevasses on the surfaces of glaciers.

Answer to Problem 15TE

When the glacier behaves as a rigid, brittle mass, then crevasses are developed on the surface of glaciers.

Explanation of Solution

Crevasses are huge gaping cracks on the surface of glaciers. These are formed by changing stresses as ice moves. The movement of glacier is both external and internal movement. These movements are caused by the frictional drag. The external drive of a glacier is gentlest at the bottom and quick at the top surface because of the frictional drag. The ice at the sides and base will move at a slower pace with respect to the ice at the surface of the glacier. When the rigid glacier is moving over a rough surface then shear stress is generated between two rigid surfaces which creates huge gaping cracks.

Conclusion:

Therefore, when the glacier behaves as a rigid, brittle mass, then crevasses are developed on the surface of glaciers.