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.
76148 videos foundNext > 

https://youtube.com/devicesupport

50 feet down in a crevasse after fall, Chamonix

On February 17, 2015 I was snowboarding off-piste on Glacier des Rognons in the Grands Montets resort in Chamonix and I fell into a deep crevasse. I sustained very minor injuries during the...

Inside a crevasse on Mt. Rainier's Nisqually Glacier

My BCC (Basic Climbing Class) team lowers me into a small crevasse on the Nisqually Glacier on Mt. Rainier to practice the "z-pully", a method of crevasse rescue. Scenario: Three people are...

Extreme Snowboarder falls into Crevasse

After a morning of powder Brad managed to find a small Crevasse in the mountains of Japan.

mike falls in crevasse

glacier riding at artic man and snow bridge falls in behind me as mike was following, you can hear his sled go in as I crest over the hill, listen for the can in the background. An hour later...

Climber films 20m crevasse fall in Himalayas - BBC News

Watch this dramatic video as seriously injured US climber John All struggles to survive after falling 70 feet (20m) into a crevasse in the Himalayas. He broke several ribs and fractured an...

Programa "I Shouldn't Be Alive" (Sobreviví), Episodio "Killer Crevasse" (Discovery Channel)

Video publicado con el objetivo de difundir nuestro trabajo y asesorías en Coordinación de Stunts y Coreografía de Peleas. Video posted for the purpose of sharing our work and consultancies...

2 Person Rope Team Crevasse Rescue

This video shows my variation for 1 on 1 Crevasse Rescue. Presenter - Darrell Weston Fallen Climber - Dana Tofell Videographer - Matt Blecharz.

Skier Falls into Crevasse - Hangs by one toepiece

Ben Ditto falls into a crevasse in Alaska and is saved by his Dynafit toepiece!

Crevasse Rescue

A practical demonstration of crevasse rescue using an unassisted hoist. Taken from the Mountaineering Council of Scotland's Alpine Essentials DVD. Full DVD available here: http://www.mcofs.org.u...

76148 videos foundNext > 

5962 news items

KTUU.com

KTUU.com
Sun, 29 Mar 2015 16:31:37 -0700

What was supposed to be an afternoon of fun with friends, snow-machining to the top of Eureka Glacier, soon turned into a nine hour rescue operation, when snow-machiner Robert McClintock fell 73 feet into a narrow crevasse on the glacier. The 69-year ...

The Guardian

The Guardian
Sun, 12 Apr 2015 04:17:11 -0700

Two skiers have been rescued from a crevasse in a glacier high in the Alps after nearly 24 hours. Maria Riedler, a mountain rescue spokeswoman, told the Austria Press Agency that the men, an Austrian and a German, were plucked out of the crevasse by ...
 
Fairbanks Daily News-Miner
Sun, 29 Mar 2015 10:49:39 -0700

ANCHORAGE, Alaska — The Alaska Air National Guard and Alaska State Troopers on Saturday came to the aid of a man who fell into a crevasse on Eureka Glacier. Troopers say they took a call just after 5:30 p.m. from 59-year-old Shawn Murphy of North ...

ABC Online

ABC Online
Sun, 29 Mar 2015 06:03:55 -0700

Melbourne man Jonathan Cawood says he was in the right place at the right time when he rescued a tourist who slipped and fell into a crevasse in New Zealand in January 2014. Mr Cawood, 23, and his friend, Mitchell Stephen, are among those to receive a ...

New York's PIX11 / WPIX-TV

New York's PIX11 / WPIX-TV
Mon, 27 Apr 2015 04:16:17 -0700

They also rope together so that if someone get buried or falls into a crevasse, the others can drag him/her out. ROLE OF WEATHER AND ALTITUDE IN MOUNTAINEERING. Weather is key–if the conditions are not right, especially with really high winds, low ...

NBCNews.com

LAist
Mon, 27 Apr 2015 10:03:45 -0700

Taplin loved traveling to extreme landscapes around the world and mountaineering. Taplin wrote a book about climbing Aconcagua in the early 1990s. On his first try, he fell into a crevasse, broke his arm but was able to pull himself up to where he ...

San Antonio Magazine

San Antonio Magazine
Mon, 27 Apr 2015 10:15:00 -0700

When the fog rolls in near Queenstown on New Zealand's South Island, our scheduled foray by helicopter to Milford Sound gets nixed. That fjord, one of the island nation's top tourist attractions, a dream-laden crevasse on the craggy southwest side, was ...
 
The Denver Post
Sun, 26 Apr 2015 09:14:45 -0700

Davidson has had close calls while climbing in the past. His book, The Edge, written with former Denver Post reporter Kevin Vaughan, describes his fall into, and escape from, a glacial crevasse on Mount Rainier in 1992. Davidson's friend, and fellow ...
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