ESCI 2010 Lecture Notes - Lecture 14: Turbidity Current, Avalanche, Lahar
14 Mar 2016
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Useful to distinguish between two main types: rotational slide. Concave surface serves as the slip plane that the material moves down. Series of slip planes developed down same side of a hill slope (right) Get clues of down-slide movement from displaced stone: translational slides. Middle left- bedding planes in a sequence of limestone have served as slip planes. Right- surface below a layer of soil has served as slip plane. Undercutting beneath resistant rock and eventu ally a tension fracture develops that becomes the slip plane. Real causes of landslides: increase in driving force (increase of weight, decrease in resisting force. Add water to slope materials, which increases driving force and decreases resisting force because of lubrication: addition of water is a common way in which steep slopes start to move. Immediate causes of landslides: shock from earthquake, vibrations, increase in moisture.
