| Term: | Ice sheet |
| Definition: |
A dome-shaped mass of glacier ice that covers surrounding terrain and is greater than 50,000 square kilometers (12 million acres) (e.g., the Greenland and Antarctic ice sheets). NSIDCCryosphere
An ice body that covers an area of continental size, generally defined as covering 50 000 km2 or more. Currently there are only two ice sheets, the Greenland Ice Sheet and the Antarctic Ice Sheet. The latter is sometimes subdivided into the East Antarctic Ice Sheet and the West Antarctic Ice Sheet. See ice cap. IHPGlacierMassBalance A thick, subcontinental to continental-scale accumulation of glacier ice and perennial snow that spreads from a center of accumulation, typically in all directions. Also called a Continental Glacier. A mass of land ice of continental size that is sufficiently thick to cover most of the underlying bed, so that its shape is mainly determined by its dynamics (the flow of the ice as it deforms internally and/or slides at its base). An ice sheet flows outward from a high central ice plateau with a small average surface slope. The margins usually slope more steeply, and most ice is discharged through fast flowing ice streams or outlet glaciers, in some cases into the sea or into ice shelves floating on the sea. There are only two ice sheets in the modern world, one on Greenland and one on Antarctica. During glacial periods there were others. IPCC2014 Mass of ice and snow of considerable thickness, and often large area, either resting on rock or floating as an ice shelf, cf. ice cap. UKAntarcticTerms Mass of ice and snow of considerable thickness extending over a large area of land and water. WMOHydrology A mass of Ice and Snow of considerable thickness and large area. Ice Sheets may be resting on rock or floating. Ice Sheets of less than about 50,000 square km resting on rock are called Ice Caps. TrombottoGeocryology A mass of ice and snow of considerable thickness, defined as covering an area of more than 50,000 square kilometres. Swisseduc A dome-shaped glacier covering an area greater than 50,000 square kilometers. Greenland and Antarctica are considered ice sheets. During the glacial advances of the Pleistocene ice sheets covered large areas of North America, Europe, and Asia. Larger than an ice cap. PhysicalGeography A mass of ice and snow of considerable thickness and large area. Ice sheets may be resting on rock (see Inland ice sheet) or floating (see Ice shelf). Ice sheets of less than about 50,000 square km resting on rock are called ice caps. SPRI GCW |