A crevasse is a deep crack in an ice sheet or glacier (as opposed to a crevice, which 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.
Crevasses often have vertical or near-vertical walls, which can then melt and create seracs, arches, and other ice formations. These walls sometimes expose layers that represent the glacier's stratigraphy.
Crevasses 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 meters, as wide as 20 meters, and can be up to several hundred meters long.
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.
Other articles related to "crevasse, crevasses":
... Crevasse rescue is the process of retrieving a climber from a crevasse in a glacier ... Because of the frequency with which climbers break through the snow over a crevasse and fall in, crevasse rescue technique is a standard part of climbing education ... The basic assumption of crevasse rescue is that two or more climbers are tied together with a climbing rope, forming a rope team a standard number is three, one on each end ...
... A crevasse splay is a sedimentary fluvial deposit which forms when a stream breaks its natural or artificial levees and deposits sediment on a floodplain ... A breach that forms a crevasse splay deposits sediments in similar pattern to an alluvial fan deposit ... In some cases crevasse splays can cause a river to abandon its old river channel, a process known as avulsion ...
... Snow bridges may also be formed inside a crevasse making it appear shallow ... Since a snow bridge is thicker and stronger at the edge of a crevasse, a fall through a bridge usually happens at some distance from the crevasse edge ...
... 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 ... These crevasses stretch across the glacier transverse to the flow direction, or cross-glacier ... Splaying crevasses form as a result of shear stress from the margin of the glacier, and longitudinal compressive stress from lateral extension ...
... James Eaton died when he fell head first into a concealed 60 foot crevasse near the edge of the upper portion of the White River Canyon ... descending the mountain's southeast face, falling deep into a crevasse on the Newton-Clark Glacier ... two other men fell on the south side of the peak and slid into a crevasse ...