| A | B |
|---|
| erosion | a process that wears away surface materials and moves them from one place to another |
| deposition | a final stage of an erosional process |
| mass movement | when gravity alone causes materials to move down slope |
| slump | mass movement that happens when loose materials or rock layers slip down a slope |
| creep | mass movement that occurs when sediments slowly inch their way down a hill |
| glacier | moving mass of ice and snow |
| plucking | process that adds boulders, gravel, and sand to a glacier's bottom and sides as water freezes and thaws and breaks off pieces of surrounding rocks |
| moraine | ridge of material deposited in the middle and along the sides of a glacier |
| deflation | erosion caused by wind blowing across loose sediments, eroding only fine grained particles such as clay and sand , and leaving behind coarse sediments |
| abrasion | erosion that occurs when wind blown sediments strike rock, scraping the surface and wearing it away |
| loess | wind deposits of fine grained, tightly packed sediments |
| till | mixture of different sized sediments droped from the base of a slowing glacier and that can cover huge areas of land |
| runoff | water that doesn't soak into the ground or evaporate but instead flows across earth's surface |
| wrill erosion | type of surface water erosion caused by runoff, in which a samll stream forms during a heavy rain, carries away plants and soil, and leaves a scar or channel on the side of a slope |
| gully erosion | type of surface water erosion due to run off that occurs when a wrill channel becomes broader and deeper |
| sheet erosion | type of surface water erosion due to runoff, in which rainwater flowing into lower elevations loses energy and leaves behind sediments that cover the soil like a sheet |
| drainage basin | land area from which a stream gets its water |
| meander | curve in the side of a stream formed by a fast moving channel of deep water |
| floodplain | broad, flat valley floor carved by a meandering stream |
| delta | triangular or fan shaped deposit of sediments that is formed when a stream or river slows and empties into an ocean, gulf, or lake |
| alluvial fan | triangular deposit of sediments that is formed when a river empties from a mountain valley out onto a flat, open plain |
| groundwater | water that soaks into the ground and collects in the small spaces between bits of rock and soil |
| permeable | describes rock and soil that have connecting pore spaces through which water can pass |
| impermeable | material through which water cannot pass |
| aquafer | layer of permeable rock that allows water to move freely |
| water table | upper surface of the zone of saturation, which is the area where all the pores in the rock are filled with water |
| spring | point where the water table meets earth surface and water flows out |
| geyser | a hot spring that erupts periodically and shoots steam and water into the air |
| cave | underground opening that is formed when acidic ground water moves through cracks in limestone and dissolves the rock |
| longshore current | ocean current that runs along the shore, moves sediment along shore lines, and is caused by waves colliding with the shore at slight angles |
| beach | deposits of sediment that run parallel to the shore |
| barrier islands | sand deposits that parallel the shore but are separated from the mainland |
