Earth Sciences 1022A/B Lecture Notes - Lecture 13: Kame, Esker, Glacier Terminus
7 Mar 2018
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Earth sciences 1022b lecture brief 15 mar 16. Glaciers: form by compaction, re-crystallization of snow that eventually turns into ice. Types include: ice sheets that are radial-spreading large ice masses on continents (e. g. antarctica); and valley in mountains, commonly flow down old stream valleys. If accumulation > ablation, the glacier"s terminus commonly advances; If accumulation < ablation, its terminus usually retreats. Internal movement within a glacier is always toward the front, even during retreat. Forms lateral moraines built along the sides of valley glaciers; end moraines (curved ridges) at the glacier terminus where it piles debris by dumping and bulldozing; and ground moraine is plastered beneath glaciers. Causes: plate tectonics and continental drift bring a major continent over a pole, allowing glaciation to start (by inducing global cooling) Glaciations are controlled by three cycles related to earth"s orbit around the sun.
