A

David

Darling

avalanche

Avalanche from Curtis Ridge on Mount Rainier, 23 Oct 1992

Avalanche from Curtis Ridge on Mount Rainier, 23 Oct 1992. Image: USGS.


An avalanche is a mass of snow, ice, and mixed rubble moving down a mountainside or over a precipice, usually caused by loud noises or other shock waves acting on snow already unstable from subsurface thawing. Avalanches can be major factors in erosion.