Why is it possible for rock avalanches to move at speeds in excess of 200 kilometers per hour?
A)They are moving with large quantities of water.
B)They are moving with molten material such as lava.
C)They are moving with large quantities of air trapped and compressed beneath the debris.
D)They are moving with large chunks of ice compressed beneath the moving material.

Question

Quizplus · Accepted Answer

Rock avalanches can move at speeds in excess of 200 kilometers per hour because they are moving with large quantities of air trapped and compressed beneath the debris. This causes a cushioning effect and reduces friction with the ground.

Why Is It Possible for Rock Avalanches to Move at Speeds