angle of repose
The angle of the steepest slope that a pile of uncemented material can attain without collapsing from the pull of gravity.
A turbulent cloud of debris mixed with air that rushes down a steep hill slope at high velocity; the debris can be rock and/or snow.
The detachment or sliding horizon on which downslope movement of rock or debris occurs.
A thick slurry formed when volcanic ash and debris mix with water, either in rivers or from rain or melting snow and ice on the flank of a volcano.
The transformation of seemingly solid sediment into a liquid-like slurry, in response to ground shaking.
A situation or setting caused by natural processes that can result in damage to society.
Downslope movement in which a mass of regolith detaches from its substrate along a spoon-shaped sliding surface and slips downward semicoherently.
The type of creep characteristic of tundra regions; during the summer, the uppermost layer of permafrost melts, and the soggy, weak layer of ground then flows slowly downslope in overlapping sheets.