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.
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.
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.
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 re
sting on rock are called ice caps.
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 interna
lly 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.
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).
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 larg
e areas of North America, Europe, and Asia. Larger than an ice cap.
An ice mass which 1) is attached to the coast 2) at least 2 meters in thickness 3) forms where a glacier or ice mass flows down to a coastline and onto the ocean surface and 4) grows by annual snow ac
cumulation or by the seaward extension of land glaciers.
A thick ice formation with a fairly level surface, formed along a polar coast and in shallow bays and inlets, where it is fastened to the shore and often reaches bottom. An ice shelf may grow hundreds
of miles out to sea. It is usually an extension of land ice, and the seaward edge floats freely in deep water. The calving of an ice shelf forms tabular icebergs and ice islands. (Also called shelf ice; formerly barrier.)
Sea ice terminology. Describes a floating ice sheet of considerable thickness that is visible 2 metres or more above sea level, and is attached to the coast. They usually have great horizontal extensi
on, and a level or gently rolling surface. Ice shelf growth occurs with annual snow accumulation, and also by the extension of land glaciers over see. Limited areas of the ice shelf may be attached to land. The edge facing the sea is termed as ice front.
A floating ice sheet of considerable thickness showing 2-50 m or more above sea-level, attached to the coast or a glacier. Usually of great horizontal extent and with a level or gently undulating surf
ace. Nourished by annual snow accumulation at the surface and often also by the seaward extension of land glaciers. Limited areas may be aground. The seaward edge is termed an ice front.
The floating terminus of a glacier, typically formed when a terrestrial glacier flow into a deep water basin, such as in Antarctica and the Canadian Arctic.
A floating slab of ice of considerable thickness extending from the coast (usually of great horizontal extent with a very gently sloping surface), often filling embayments in the coastline of an ice s
heet. Nearly all ice shelves are in Antarctica, where most of the ice discharged into the ocean flows via ice shelves.