View source for Snow bridge

{{Short description|Arc formed of snow across a crevasse}}
{{for|various man-made structures to protect from avalanches|Snow barrier (disambiguation)}}
[[File:Snow bridge near Småtindisen.jpg|thumb|A snow bridge across a creek]]
A '''snow bridge''' is an arc formed by snow across a [[crevasse]], a crack in rock, a [[Stream|creek]], or some other opening in terrain.<ref>Elaine Freedgood (2000) ''Victorian Writing about Risk: Imagining a Safe England in a Dangerous World'', {{ISBN|0-521-78108-6}} [https://books.google.com/books?id=VnUZ3QKII-kC&dq=%22snow+bridge+is%22&pg=PA193 p.&nbsp;193].</ref> It is typically formed by [[snow drift]], which first creates a [[cornice (climbing)|cornice]], which may then grow to reach the other side of the opening.

==Dangers==

[[Image:Glaciereaston.jpg|thumb|right|200px|A snow bridge concealing a crevasse in the back]]
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.<ref>Tony Holt (Spring 2002) [http://www.chauvinguides.com/BernerJournal/bernerjournal1.htm "Berner Oberland Haute Route Journal"], Chauvin Guides International, [https://web.archive.org/web/20070813193230/http://www.chauvinguides.com/BernerJournal/bernerjournal1.htm archived] 2007-08-13.</ref>

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.<ref>''Mountain Operations'' (September 1947) United States War Department Field Manual FM-10, {{OCLC|11663687}} [https://books.google.com/books?id=odEsAAAAIAAJ&q=%22snow+bridge+is%22 p.&nbsp;204]</ref>

==See also==
*[[Ice bridge]]

==References==
<references/>


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[[Category:Glaciology]]
[[Category:Snow]]
[[Category:Bridges]]
[[Category:Ice bridges]]


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