EOSC 110 Lecture Notes - Lecture 12: Mass Wasting, Surface Tension, Shear Stress
Document Summary
Mass wasting: downslope movement of rock and debris under the. Landslide: a general term for all types of mass movement. Causes are contributing factors that make the slope vulnerable to failure. Trigger is the single event that initiates movement. Triggering mechanisms: earthquakes, weight added to upper part of a slope, undercutting of bottom of slope, heavy rainfall, volcanic activity, human modification. Gravity is the driving force: they want to make mountains flat, bring rocks down to lower surfaces. In unconsolidated materials like soil, we consider the strength of the material (shear strength) Bedding or fractures act as planes of weakness. Low porosity rocks in a sequence can prevent groundwater from seeping away - providing a plane of weakness. Unsaturated soil or debris vs. saturated soil or debris. Important force apart and the material flows: debris avalanche flowing debris. Starts as a rotated block then within that block comes: a slump-earth flow complex is a common slope failure event.
