EARTHSS 21 Study Guide - Final Guide: Permafrost, Rock Flour, Mendenhall Glacier
20 Jul 2016
School
Department
Course
Professor
Document Summary
Study guide for ess 21 final spring 2016. Be able to explain how the following landscape features form due to glacial erosion and recognize them from photos/diagrams: polished surfaces and striations. Rock fragments embedded in glacial ice act like sandpaper on underlying bedrock. The moving ice abrades and polishes substrates, producing a fine pulverized rock flour . Larger rocks gouge lines in bedrock called striations . Smooth, polished mountains as a result: roche moutonees. Glacial ice picks up rock fragments and incorporates them into the internal flow. Roche moutonn e are asymmetric bedrock hills shaped by ice: u-shaped valleys and fjords. Before glaciation, valleys are v-shaped, and tributary mouths are the same elevation as the trunk stream. During glaciation, the valleys fill with ice and are aggressively eroded and oversteepened. After glaciation, the landscape is transformed, containing u-shaped valleys, hanging valleys, cirques, ar tes, horns. Fjords are u-shaped glacial troughs that have become flooded by the sea: hanging valleys.
