digplanet beta 1: Athena
Share digplanet:

Agriculture

Applied sciences

Arts

Belief

Business

Chronology

Culture

Education

Environment

Geography

Health

History

Humanities

Language

Law

Life

Mathematics

Nature

People

Politics

Science

Society

Technology

Crevasse is also a traditional term for a levee breach.

A crevasse is a deep crack, or fracture, found in an ice sheet or glacier, as opposed to a crevice that forms in rock. Crevasses form as a result of the movement and resulting stress associated with the shear stress generated when two semi-rigid pieces above a plastic substrate have different rates of movement. The resulting intensity of the shear stress causes a breakage along the faces.

Description[edit]

Crevasses often have vertical or near-vertical walls, which can then melt and create seracs, arches, and other ice formations.[1] These walls sometimes expose layers that represent the glacier's stratigraphy. They are widely distributed across Antarctica and are more narrow at depth as it is here that pieces of the glacier may rub and break against each other. Crevasse size often depends upon the amount of liquid water present in the glacier. A crevasse may be as deep as 45 metres, as wide as 20 metres, and can be up to several hundred metres long.

A crevasse may be covered, but not necessarily filled, by a snow bridge made of the previous years' accumulation and snow drifts. The result is that crevasses are rendered invisible, and thus potentially lethal to anyone attempting to navigate their way across a glacier. Occasionally a snow bridge over an old crevasse may begin to sag providing some landscape relief, but this cannot be relied upon. Anyone planning to travel on a glacier should be trained in crevasse rescue.

The presence of water in a crevasse can significantly increase its penetration. Water-filled crevasses may reach the bottom of glaciers or ice sheets and provide a direct hydrologic connection between the surface, where significant summer melting occurs, and the bed of the glacier, where additional water may lubricate the bed and accelerate ice flow.

Types of crevasses[edit]

  • Transverse crevasses are the most common crevasse type and they form in a zone of longitudinal extension where the principal stresses are normal to the direction of glacier flow, creating extensional tensile stress. These crevasses stretch across the glacier transverse to the flow direction, or cross-glacier. They generally form where a valley becomes steeper.[2]
  • Splashing crevasses form as a result of shear stress from the margin of the glacier, and longitudinal compressing stress from lateral extension. They extend from the margin of the glacier and are concave up with respect to glacier flow, making an angle less than 45° with the margin. At the centre line of the glacier, there is zero pure shear from the margins, so this area is typically crevasse-free.
  • Longitudinal crevasses form parallel to flow where the glacier width is expanding. They develop in areas of compressing stress, such as where a valley widens or bends. They are typically concave down-glacier, and form an angle greater than 45° with the margin.[2]

Gallery[edit]

Crevasses around the world
Crevasse on the Gorner Glacier, Zermatt, Switzerland 
Measuring snowpack in a crevasse on the Easton Glacier, Mount Baker, North Cascades, United States 
Exploring the bottom of a crevasse in Antarctica 
Crevasse on the Ross Ice Shelf, January 2001 
Crevasses on the Upper Price Glacier of Mt. Shuksan, North Cascades, WA. Photo taken August 2011 
Split-boarder skiing up past open crevasses on the Coleman Glacier of Mt. Baker. Photo taken October 2009 
Looking down into a crevasse on Mt. Rainier, Cascade range, WA. Photo taken Mid August 2009 
Crevasses on Mt. Rainier. Photo taken from the Disappointment Cleaver Route on Mt. Rainier. Photo taken August 2009 
Mountaineers crossing a crevasse on Mt. Rainier. Photo taken August 2009 
Ladder bridging a crevasse on Mt. Rainier. Photo taken Aug. 2009 

See also[edit]

References[edit]

  1. ^ van der Veen, C (1990). "Crevasses on Glaciers". Polar Geography 23 (3): 213–245. doi:10.1080/10889379909377677. 
  2. ^ a b Holdsworth, G (October 1956). "Primary Transverse Crevasses". Journal of Glaciology 8 (52): 107–129. 

Bibliography[edit]

  • Paterson, W.S.B., 1994, The Physics of Glaciers, 3rd edition, ISBN 0-7506-4742-6.
  • Boon, S., M.J. Sharp, 2003, The role of hydrologically-driven ice fracture in drainage system evolution on an Arctic glacier, Geophysical Research Letters, 30, pp. 1916.
  • van der Veen, C.J., 1998, Fracture mechanics approach to penetration of surface crevasses on glaciers, Cold Regions Science and Technology, 27, pp. 31–47.
  • Zwally, H.J., W. Abdalati, T. Herring, K. Larson, J. Saba, K. Steffen, 2002, Surface melt-induced acceleration of Greenland ice-sheet flow, Science, 297, pp. 218–222.
  • Mountaineering: The Freedom of the Hills, 5th edition. ISBN 0-89886-309-0.
  • "Crevasse." Encyclopædia Britannica. 2010. Encyclopædia Britannica Online. 17 Oct. 2010.
  • Das, S. B., I. Joughin, M.D. Behn, I.M. Howat, M.A. King, D. Lizarralde, M.P. Bhatia, 2008, Fracture propagation to the base of the Greenland Ice Sheet during supraglacial lake drainage, Science, 320, pp. 778.

External links[edit]

  • Media related to Crevasse at Wikimedia Commons

Templates[edit]


Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Crevasse — Please support Wikipedia.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.
1 videos found

https://youtube.com/devicesupport

https://youtube.com/devicesupport http://m.youtube.com

 
1 videos found

7685 news items

9news.com.au

9news.com.au
Sun, 03 May 2015 16:53:52 -0700

Video shows the wetsuited adventurer plunging 6m down a gaping crevasse of the Canyon Groin in the Rhône-Alpes region of southeast France. The man lands with a splash into water at the bottom of the canyon as the group he is travelling with look on in ...

Latin Post

Latin Post
Thu, 28 May 2015 09:18:45 -0700

... everything from Sunday-best dresses and suits to super-casual Friday shorts and T-shirts," to spell terms such as vexillology (the study of flags), amphictyony (a league of ancient Greek states), and bergschrund (a crevasse), the Washington Post ...

The Spokesman Review

The Spokesman Review
Thu, 28 May 2015 00:05:32 -0700

Nearly every weekend, volunteer leaders taught special classes on skills such as placing anchors, belaying, rock climbing, glacier travel and crevasse rescue. A weekend snow practice at Stevens Peak involved a 4 a.m. alpine start from camp to get used ...
 
Washington Post
Wed, 27 May 2015 11:25:11 -0700

Words such as vexillology (the study of flags), amphictyony (a league of ancient Greek states), and bergschrund (a crevasse). Some heard the word and spelled it immediately. Others asked for it to be repeated. A few practiced writing it in the air with ...

Yorkshire Post

Yorkshire Post
Wed, 27 May 2015 11:14:56 -0700

My climbing partner stayed clipped on reasoning that he could easily be swept into a crevasse by the power of the snow. Fortunately we both survived, but it could have been different.” When the tremors ceased and visibility returned, David knew he had ...

Grand Junction Free Press

Grand Junction Free Press
Wed, 27 May 2015 08:00:00 -0700

He tumbled into a crevasse and broke his arm, but he hauled himself out as other mountaineers came to his rescue. In 1992, he wrote about it in, “Aconcagua, the Stone Sentinel: Perspectives of an Expedition.” About Tom Taplin. Thomas Ely Taplin, Jr ...

Los Angeles Times

Los Angeles Times
Tue, 26 May 2015 08:34:58 -0700

The vegetation and dirt along the oil's path from the culvert downhill to the ocean has been ripped out, revealing what looked like a black river of stained dirt. The crevasse in the cliffs where the oil poured straight down to the beach was completely ...

camer.be

camer.be
Sat, 23 May 2015 06:28:34 -0700

La circulation a été perturbée pendant plusieurs heures sur le pont du Wouri le mardi 19 mai 2015 à Douala. Pour cause, une crevasse s'est créée à l'entrée ouest de l'ouvrage. L'ouverture de près de 80 cm de diamètre laissait entrevoir une des ...
Loading

Oops, we seem to be having trouble contacting Twitter

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!

Searchlight Group

Digplanet also receives support from Searchlight Group. Visit Searchlight