Slides & Slumps
Slides and slumps occur when sediment slides down a hillslope along a distinct plane. Usually activated by precipitation or debuttressing. What distinguishes a slide from a slump is both the shape of the plane along which it slides, and how fast. Slides generally occur along a linear plane, parallel or sub-parallel to the hillslope surface, and generally happen in seconds to minutes. Slumps on the other hand occur along concave planes, and occur over hours to days or even months. (There are exceptions to the speed rule, the Oso Landslide for example was a slump, but happened in a matter of seconds due to its scale, and the level of saturation of the soils).