ESCI 1001 Lecture Notes - Lecture 14: Himalayas, Negative Feedback, Plate Tectonics
Document Summary
The landscapes of vast areas of many continents have been sculpted by the flow of ice in glaciers. Today, 10% of land covered by glacial ice. 20,000 years ago: ~30% covered by glacial ice, sea level dropped. Persists for a significant amount of time. Exhibits downslope or outward movement due to gravity. Cyrosphere: all of the ice on earth. Ice sheet covering all land within its margins (95% of all glacial ice) At the shores of a land mass the ice sheet may flow onto the ocean to form an extensive, floating ice shelf. Snow line: lower limit of perennial snow: depends on local climate. Abundant winter snowfall that does not melt away in summer. High altitudes: precipitation to make snow. Ice is a rock composed of the mineral ice. Conversion of snow to glacial ice: years decades. Equilibrium line = boundary between accumulation and ablation zones: accum < ablation (ice front recedes, accum > ablation (ice front advances)
