GEOL 118 Lecture Notes - Lecture 19: Landslide Classification, Earthflow
4 Apr 2016
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Document Summary
Downslope movement of rock, sediment that occurs at earth"s surface in response to gravity. Variable speeds- extremely fast to extremely slow. They shape our landscape ( with river erosion ) Landslides and gravity have not flattened mountain ranges because of rejuvenation. Steep slopes and heavy rain have greatest risk for landslides. Can be greatly influenced by human activities (often making problem worse) Most landslide classification systems based on type of downslope movement, speed of movement, earth material involved (rock vs. soil), and amount of water. Example: individual grains are mixed around during movement. Slide-slip- earth material moves as coherent block in contact with slope. Fall- earth material moves as free fall (out of contact with slope) Movement occurs along free face inflows and slides. Speed ranges from imperceptibly slow (creep) to extremely fast (avalanche) Creep is very slow continuous downslope movement of rock or sediment. Process involves outward expansion of earth and downward contraction of earth.
