EAR 105 Lecture Notes - Lecture 15: Ice Shelf
Document Summary
Glacier = permanent mass of moving ice made of compressed snow and ice on land. Glaciers now: occupy about 10% of total land area, most are in polar regions antarctica (85%) and greenland (10%, the rest, are mountain glaciers. Glaciers once covered 30% of the land area of the earth and left deposits of diverse shape and composition: glaciers are extremely important factors in the regulation of earth"s temperatures. Glaciers are made of ice, but form by extensive snowfall. Snow crystals transform with depth first making firn" then finally ice crystals. Continental glaciers: ice shelves - glacial ice extending into sea, ice caps - miniature ice sheets. Most of the mass losses happened in glacier system. Alpine (mountain, valley) glaciers piedmont glaciers - valley glaciers flow onto flat plains. Alpine (mountain, valley) glaciers cirque glaciers - in bowl-like hollows in high mountains. Hanging glaciers - cling to steep mountainsides (when melted leave hanging valleys behind)
