Icefall

An icefall is a portion of certain glaciers characterized by relatively rapid flow and chaotic crevassed surface, caused in part by gravity.

The term icefall is formed by analogy with the word waterfall, which is a similar phenomenon of the liquid phase but at a more spectacular speed.

When the movement of the ice slows down, the crevasses can coalesce, resulting in the surface of the glacier becoming smoother.

This change in speed and pressure causes crevasses to close up, resulting in a smoother glacier surface that presents fewer challenges for navigation and traversal.

The Roosevelt Glacier icefall, on the north face of Mount Baker (Cascade Range, U.S.), is about 730 metres (2,400 feet) high.