A snow bridge is an arc formed by snow across a crevasse, a crack in rock, a creek, or some other opening in terrain.1 It is typically formed by snow drift, which first creates a cornice, which may then grow to reach the other side of the opening.
Dangers
A snow bridge may completely cover the opening and thus present a danger by creating an illusion of unbroken surface under which the opening is concealed by an unknown thickness of snow, possibly only a few centimetres.
Snow bridges may also form inside a crevasse, making it appear shallow.2
A snow bridge is thicker and stronger at the edge of a crevasse; therefore, a fall through a bridge usually happens at some distance from the edge.3
References
References
- Elaine Freedgood (2000) Victorian Writing about Risk: Imagining a Safe England in a Dangerous World, ISBN 0-521-78108-6 p. 193.
- Tony Holt (Spring 2002) "Berner Oberland Haute Route Journal", Chauvin Guides International, archived 2007-08-13.
- Mountain Operations (September 1947) United States War Department Field Manual FM-10, OCLC 11663687 p. 204