crevasse

crevasse krəvăsˈ [key], large crack in the upper surface of a glacier, formed by tension acting upon the brittle ice. Transverse crevasses occur where the grade of the glacier bed becomes suddenly steeper; longitudinal crevasses, where the glacier spreads over a wider valley or plain. Marginal crevasses are due to the strain built up when the central part moves faster than the sides.

See more Encyclopedia articles on: Geology and Oceanography