| A | B |
|---|
| mass movement | downslope movement of Earth materials, due to gravity, that can occur suddenly or very slowly |
| creep | slow, steady downhill movement of loose weathered Earth materials, especially soils, causing objects on a slope to tilt |
| mudflow | rapidly flowing, often destructive mixture of mud and water that can be triggered by an earthquake, intense rainstorm, or volcanic eruption |
| landslide | rapid downslope movement of a mass of loose soil, rock, or debis that has separated from bedrock |
| slump | mass movement that occurs when Earth materials in a landslide rotate and slide along a curved surface, leaving a crescent-shaped scar on a slope |
| avalanche | landslide that occurs in a mountainous area when snow falls on an icy crust, becomes heavy, slips off, and slides swiftly down a mountainside |
| friction | resistance to sliding and rolling between a material and the surface |
| deflation | lowering of land surface as a result of wind erosiion |
| abrasion | sand and other particles rubbing against the surface of rocks |
| ventifact | rocks shaped by wind-blown sediments |
| dune | a pile of wind-blown sand |
| loess | wind-blown silt deposits with a high concentration of nutrients |
| migrate | to move from one location to another |
| glacier | mass of ice that forms at Earth's poles and in mountainous regions at high elevations |
| valley glacier | a glacier that forms in a valley in a mountainous area and widens V-shaped stream valleys into U-shaped glacial valleys as it moves downslope |
| continental glacier | a glacier that forms over broad, contrinent-sized area of land and usually spteads out from its center |
| cirque | a deep depression scooped out by a valley glacier |
| moraine | a ridge of mixed debris deposited by a melting glacier |
| outwash plain | area at the leading edge of a glacier, where outwash is deposited by meltwater streams |
| drumlin | an elongated landform that results when a glacier moves over an older moraine |
| esker | a long, winding ridge of layered sediments deposited by streams that flow beneath a melting glacier |
| kame | a mound of layered sediment similar to an esker in origin but is conical in shape |
| kettle | a lake formed by a hole in the ground left by a melted block of ice |
