Glaciers
DYNAMIC PLANET
Firn and ne’ve’ are repeated melting and refreezing forms of granules
Background info
Unconstrained these glaciers cover vast areas. Topography does not play a major role in the extent of these glaciers.
Ice sheets and ice caps fall into the same category. The difference between them is one of scale. Ice sheets are larger. Typically the dividing line is around 50,000 km2. The glaciers that cover Antarctica and Greenland are ice sheets, and the glacier that covers Iceland is an ice cap. Two main components of ice sheets and ice caps are ice domes and outlet glacier.
Ice shelves An ice shelf is a very thick sheet of ice that has been shoved out over the sea floor from a land-based glacier. It is still attached to land on one side but most of it is afloat. Massive icebergs (glossary) may calve off of ice shelves.
Constrained These are the glaciers that are found in rugged topography and are typically bound within a valley or depression.
Icefields An icefield is an extensive area of land ice covering a mountain region; its surface is approximately level and can be distinguished from an ice cap because it does not achieve the characteristic domelike shape, and because flow is strongly influenced by the underlying topography.
Valley glaciers A valley glacier flows between the walls of a mountain valley in all or part of its length. It may originate in an icefield or a cirque.
Cirque glaciers A cirque glacier is a small ice mass generally wide in relation to its length and characteristically occupying an armchair-shaped bedrock hollow. It is the most common type of glacier in the mountains of the western United States.
Other small glaciers This category includes a wide variety of glaciers whose forms are closely controlled by the underlying topography. The permutations are almost limitless. Typically small glaciers are found in hollows or slight depressions in mountainous terrain or bordering coastlines. Cirque glacier-glacier confined by valley
Firn and ne’ve’ are repeated melting and refreezing forms of granules
Background info
Unconstrained these glaciers cover vast areas. Topography does not play a major role in the extent of these glaciers.
Ice sheets and ice caps fall into the same category. The difference between them is one of scale. Ice sheets are larger. Typically the dividing line is around 50,000 km2. The glaciers that cover Antarctica and Greenland are ice sheets, and the glacier that covers Iceland is an ice cap. Two main components of ice sheets and ice caps are ice domes and outlet glacier.
Ice shelves An ice shelf is a very thick sheet of ice that has been shoved out over the sea floor from a land-based glacier. It is still attached to land on one side but most of it is afloat. Massive icebergs (glossary) may calve off of ice shelves.
Constrained These are the glaciers that are found in rugged topography and are typically bound within a valley or depression.
Icefields An icefield is an extensive area of land ice covering a mountain region; its surface is approximately level and can be distinguished from an ice cap because it does not achieve the characteristic domelike shape, and because flow is strongly influenced by the underlying topography.
Valley glaciers A valley glacier flows between the walls of a mountain valley in all or part of its length. It may originate in an icefield or a cirque.
Cirque glaciers A cirque glacier is a small ice mass generally wide in relation to its length and characteristically occupying an armchair-shaped bedrock hollow. It is the most common type of glacier in the mountains of the western United States.
Other small glaciers This category includes a wide variety of glaciers whose forms are closely controlled by the underlying topography. The permutations are almost limitless. Typically small glaciers are found in hollows or slight depressions in mountainous terrain or bordering coastlines. Cirque glacier-glacier confined by valley