A portion of a glacier that travels much more quickly than adjacent portions of the glacier.
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 maybe indistinct.
A zone of high velocity within an ice cap or ice sheet. By analogy with flood waters, which have high velocities within their channels but low velocities in the flood plain, ice streams are often (but not necessarily) associated with a subglacial trough.
A rapidly moving current of ice in an ice sheet or ice cap. Ice streams flow more quickly than the surrounding ice and remove ice from the ice sheet. Antarctic ice streams may flow about one kilometre per year (0.6 miles per year). Freshwater.
(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.
An ice stream is a region of an ice sheet that moves significantly faster than the surrounding ice. Ice streams are significant features of the Antarctic where they account for 10% of the volume of the ice. They are up to 50 km wide and 2 km thick.