EARTH 104 Study Guide - Quiz Guide: Permafrost, Drift Ice, Pancake Ice
7 Dec 2015
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Document Summary
Glacier: a persistent body of dense ice that is constantly moving under its own weight; it forms where the accumulation of snow exceeds its ablation over many years, often centuries. Firn: partially compacted snow that has been left over from past seasons and has been recrystallized into a denser substance. Ice sheet: a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km2 (19,000 sq mi). Ice shelf: a thick floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Nilas: a sea ice crust up to 10 cm (3. 9 in) in thickness. It bends without breaking around waves and swells. The ice is generally less than 1 yr old. Pancake ice: a form of ice that consists of round pieces of ice with diameters ranging from 30 cm (12 in) to 3 m (9. 8 ft), formed under the action of wind and waves.
