Geology: Geologic Hazards

Ground rotates and slides along a curved failure plane

More than half the particles larger than sand size; rate of movement varies from less than 1m/year to 100km/hr or more

Movement of fine-grained particles with large amounts of water

Movement of water clogged soil generally over permafrost

When surface material extends or spreads on gentle slopes. This type of ground deformation is often associated with earthquake shaking

Downward slipping of a block of earth material, usually with a backward rotation on a concave surface

Usually rapid movement of a newly detached segment of bedrock

Material falls freely in air, typically occurs in bedrock

Ground slide with little rotation along a flat plane parallel to the surface

Gravity sends rocks and other materials tumbling downslope