GEOG 1050 Lecture Notes - Lecture 4: Pleistocene, Firn, Sandpaper
Document Summary
Glaciers: ice = glacial periods, ice free = interglacials, pleistocene epoch: ice covered about 1/3 of earth, wisconsin period: 18,000 - 10,000 years ago, depressions: large amounts of meltwater lled depressions, great lakes. Hold about 18% of all lake water on earth. Isostatic rebound: land is rebounding from pressure taken off due to glacial retreat: climate change (natural, earth"s elliptical orbit, earth wobbles, earth"s tilt: 21 degrees - 24 degrees, glacial ice. Starts off with snow, end with glacial ice. 1) abrasion: smoothing of landscape, like sandpaper. Chatter marks: plucking- makes landscape jagged, glacial energy budget. Zone of ablation: get rid of energy. Accumulation > ablation = glacier advances, moves down slope. Accumulation < ablation = glacier retreats: alpine glaciers, landforms- all erosional. Cirque: all alpine glaciers start in cirques. Erratic- piece of landscape that"s plucked and deposited by glacier. Crevasses- cracks in ice, not all the way through. Calving- pieces of ice break off toe of glacier.
