Earth Sciences 1022A/B Lecture Notes - Lecture 8: Continental Drift, Esker, Kame
19 Oct 2015
School
Department
Course
Professor
Document Summary
Earth sciences 1022a lecture brief 13 nov 14. 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) 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. Glacial erosion: occurs by plucking (freeze-on of loose bedrock); and abrasion (using the glacier"s load to scrape, scour, gouge the subglacial floor and sides) striations (scratches) and grooves formed by particles in ice scraping over bedrock; Landforms created by glacial erosion: glaciated valleys (u-shaped) become fjords along coasts; aretes (sharp ridges) and horns (pyramid-shaped peaks) form where multiple cirque glaciers gnaw into a mountain divide from the sides.
