EAR 105 Lecture 16: Chapter 22: Glaciers
9 Nov 2016
School
Department
Course
Professor
Document Summary
Glacier = a permanent mass of moving ice made of compressed snow on land. 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 temperature. Occupy about 10% of total land area. Glaciers are made of ice, but form by extensive snowfall. Snowflake > granular snow > firn > glacier ice. Snow crystals transform with depth first making firn then finally ice crystals. Cirque glaciers - in bowl-like hollows in high mountains. Hanging glaciers - cling to steep mountainsides (when melted leave hanging valleys behind) Tidewater glaciers - valley glaciers that reach the sea. Ice shelves - glacial ice extending into sea. Zone of accumulation - where snow falls. Zone of wastage/ablation - where glacier melts. Crevasse - a deep crack in an ice sheet of glacier; forms as a result of movement.
