| A | B |
|---|
| glacier | a large mass of moving ice |
| alpine glacier | narrow, wedge-shaped mass of ice that forms in a moutainous region; confined to a small area by surrounding topography |
| continental glacier | a massive sheet of ice that may cover millions of square kilometers; not confined by surrounding topography |
| basal slip | the process that causes the ice at the base of a glacier to melt & the glacier to slide |
| internal plastic flow | the process by which glaciers flow slowly as grains of ice deform under pressure & slide over each other |
| crevasse | in a glacier, a large crack or fissure that results from ice movement |
| cirque | a deep & steep bowl-like depression produced by glacial erosion |
| arete | a sharp, jagged ridge that forms between cirques |
| horn | a sharp, pyramid-like peak that forms because of the erosion of cirques |
| erratic | a large rock transported from a distant source by a glacier |
| glacial drift | rock material carried & deposited by glaciers |
| till | unsorted rock material that is deposited directly by a melting glacier |
| moraine | a landform that is made from unsorted sediments deposited by a glacier |
| kettle | a bowl-like depression in a glacial drift deposit |
| esker | a long, winding ridge of gravel & coarse sand deposited by glacial meltwater streams |
| ice age | a long period of climatic cooling during which the continents are glaciated repeatedly |
| Milankovitch theory | the theory that cyclical changes in Earth's orbit & in tilt of Earth's axis occur over thousands of years |
