| Term | Definition |
|---|
| Glacier | moving body of ice on land that flows downslope or outward from an area of accumulation |
| Little Ice Age | an interval from about 1500 to the mid-to-late- 1800 during which glaciers expanded to their greatest historical extent |
| Valley Glacier | a glacier confined to a mountain valley or an interconnected system of mountain valleys |
| Continental Glaciers | a glacier that covers a vast area (at least 50,00km2) and is not confined by topography: also called ice sheet |
| Ice Cap | a dome-shaped mass of glacial ice that covers less than 50,000km2 |
| Glaciation | refers to all aspects of glaciers, including their origin, expansion, and retreat, and their impact on the earth's surface |
| Glacial Ice | water in the solid state within a glacier: forms as snow partially melts and refreezes and compacts so that it is transforms first to firn and then to glacial ice |
| Plastic Flow | the flow that takes place in response to pressure and causes deformation with no fracturing |
| Basal Slip | movement involving a glacier sliding over its underlying surface |
| Glacial Budget | the balance between expansion and contraction of a glacier in response to accumulation versus wastage |
| Zone of Accumulation | the part of a glacier where additions exceeds losses and the glacier's surface is perennially covered with snow. |
| Zone of Wastage | the part of a glacier where losses from melting, sublimation, and calving of icebergs exceed the rate of acculmation |
| Glacial Surge | a time of greatly accelerated flow in a glacier. commonly results in displacement of the glacier's terminus by several km |
| Abrasion | the process whereby rock is worn smooth by the impact of sediment transported by running water, glaciers, waves, and winds |
| Glacial Polish | a smooth, glistening rock surface formed by the movement of sediment-laden ice over bedrock |
| Glacial Striations | a straight scratch rarely more than a few millimeters deep on a rock caused by the movement of sediment-laden glacial ice |
| U-Shaped glacial trough | a valley with steep or vertical walls and a broad, rather flat floor formed by the movement of a glacier through a stream valley |
| fiord | an arm of the sea extending into a glacial trough eroded below sea level |
| hanging valley | a tributary glacial valley whose floor is at a higher level that than of the main glacial valley |
| Glacial drift | a collective term for all sediment deposited directly by glacial ice (till) and by meltwater streams (outwash). |
| glacial erratics | a rock fragment carried some distance from its source by a glacier and usually deposited on bedrock of a different compostion |
| stratified drift | glacial deposits that show both stratification and sorting |
| end moraines | a pile or ridge of rubble deposited at the terminus of a glacier |
| ground moraines | the layer of sediment released from melting ice as a glacier's terminus retreats |
| recessional moraines | an end moraine that forms when a glacier;s terminus retreats, the stabilizes, and a ridge or mound of till is deposited |
| lateral moraines | ridge of sediment deposited along the margin of a valley glacier |
| medial moraine | a moraine carried on the central surface of a glacier; formed where two lateral moraines merge |
| drumlins | an elongate hill of till formed by the movement of a continental glacier or by floods |
| valley trains | a long, narrow deposit of stratified drift confined within a glacial valley |
| outwash plain | the sediment deposited by meltwater discharging from a continental glacier's terminus |
| kames | conical hill if stratified drift originally deposited in a depression on a glacier's surface |
| eskers | a long, sinuous ridge of stratified drift deposited by running water in a tunnel beneath stagnant ice. |
| Milankovitch theory | an explanation for the cyclic variations in climate and the onset ice ages as a result of irregularities in earth's rotation and orbit |
| firn | granular snow formed by partial melting and refreezing of snow; transitional material between snow and glacial ice |
Combine with other sets
Share on Facebook
Share on MySpace
!