| Term: | Ice stream |
| Definition: |
(1) a current of ice in an ice sheet or ice cap that flows faster than the surrounding ice (2) sometimes refers to the confluent sections of a branched-valley glacier (3) obsolete synonym of valley glaciers. NSIDCCryosphere
A part of an ice sheet or ice cap with strongly enhanced flow, often separated from surrounding ice by strongly sheared, crevassed margins. 'Pure' ice streams are bounded by ice on either side and lack significant non-glacial topographic control, while 'topographic' ice streams are constrained by the topography. An ice stream of the latter type is similar to an outlet glacier, but outlet glaciers do not necessarily have strongly enhanced flow velocity. IHPGlacierMassBalance Part of an island ice sheet in which the ice flows more rapidly and not necessarily in the same direction as the surrounding ice. The margins are sometimes clearly marked by a change in direction of the surface slope but may be indistinct. WMOSeaIce Sea ice terminology. Describes the part of an inland ice sheet in which the ice flows more rapidly and not necessarily in the same direction as the surrounding ice. ECCCanada A linear or curvilinear part of an ice sheet, often a few kilometres to a few tens of kilometres wide and tens to hundreds of kilometres long, in which the ice flows much faster than main body of the surrounding ice sheet. The margins are sometimes defined clearly by the presence of a shear zone marked by surface crevasses. UKAntarcticTerms A stream of ice with strongly enhanced flow that is part of an ice sheet. It is often separated from surrounding ice by strongly sheared, crevassed margins. See also Outlet glacier. IPCC2013 Part of an ice sheet or ice cap in which the ice flows more rapidly, and not necessarily in the same direction as the surrounding ice. Zones of strongly sheared, crevassed ice often define the margins (cf. shear zone). Swisseduc A fast-moving section of an ice sheet contained within the ice sheet. Motion of an ice stream is dominated by basal sliding. AMSglossary Part of an ice sheet in which the ice flows more rapidly and not necessarily in the same direction as the surrounding ice. The margins are sometimes clearly marked by a change in direction of the surface slope, but may be indistinct. SPRI Part of an Ice sheet; Ice flow of higher velocity than surrounding ice masses; Unrestricted by topographic features, which protrude out of the ice mass; The Primary Classification should be extended by the class 'Ice stream' because they play an important role in the drainage of the Antarctic ice sheet. Although variable in time and space, they are well defined glaciological features and are of high importance for draining the continental ice sheets. GLIMSGlacier GCW |