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Contents of 15.1 What are the characteristics of mass movements?

15.1 What are the characteristics of mass movements?

• Mass movements are downslope movement of rock, regolith, or both due solely to gravity.
• The three characteristics used to describe mass movements are 1) the material (rock, debris, earth), 2) the type of movement (fall, slide, flow), and 3) the velocity (fast, slow).
• Falls free fall down steep slopes. Slides move along surfaces of rupture, planar or curved. Flows behave as a viscous fluid even though no water may be present.
• Landscape features such as scarps, surface cracks, tilted/bent trees, bumpy topography, and talus provide clues to the occurrence and type of mass movement.
• Some mass-movement events may involve more than one process. Rock and regolith initially separate along a rupture surface, but the slide-displaced materials may fall or flow.