GEO 101 Lecture Notes - Lecture 21: Regrading, Granular Material, Mass Wasting
27 Mar 2017
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Document Summary
Downward travel of rock, regolith, ice and/or snow. Weathering and fracturing weaken rock at surface. Wet: held by surface tension of water. What causes expansion and contraction: freeze/thaw, heat/cool, wet/dry. Type of creep in tundra due to permafrost. Active layer: top 1-3 meters that melt during the summer. Slump: the mass that moves semi coherently down. Head scarp: top edge where regolith detaches; falls below elevation of the unmoved surroundings. Toe: bottom edge; higher elevation than unmoved surroundings. Fast: mudflow, debris flow, lahars, landslides (rock slides, debris slides, falls, avalanches. Mudflow: water mixes with regolith and flows as a slurry; only contains mud. Debris flow: contains mud and larger rock fragments. Lahar: mixture of volcanic ash and water. Sudden movement of rock ad regolith down a non-vertical slope. Rock slide: only rock and no regolith. Occur when rock/regolith detaches from the substrate along a failure surface. Sudden movement of rock and regolith down a vertical slope.
