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Glaciers
Geology final
Question | Answer |
---|---|
Glaciers are part of Two basic cycles... | Hydrologic cycle, and Rock cycle |
A think mass of ice that originates on land from the accumulation, compaction, and recrystallization of snow | Glacier |
*Exist in mountain areas*Flow down a valley from an accumulation center at it's head | Valley (alpine) glaciers |
*Exist on a larger scale than valley glaciers*Two major ice sheets on Earth are over Greenland and Antarctica*Often called continental ice sheets*Ice flows out in all directions from one or more snow accumulation centers | Ice Sheets |
Other Types of glaciers are | Ice capsOutlet glaciersPiedmont Glaciers |
Snow is recrystallized into a much denser mass of small grains called.. | Firn |
Occurs within iceUnder pressure, ice behaves as a plastic material | Plastic flow |
Entire ice mass slipping along the groundMost glaciers are thought to move this way by this process | Basal slip |
the area where a glacier forms | Zone of Accumulation |
the area where there is a net loss to the glacier due to melting | Zone of wastage |
The breaking off of large pieces of ice | Calving |
lifting of rocks | Plucking |
Rocks within the ice acting like sandpaper to smooth and polish the surface below | Abrasion |
Pulverized rock | Rock flour |
Grooves in the bedrock | Glacial striations |
material that is deposited directly by the ice | Till |
Sediments laid down by glacial meltwater | Stratified drift |
Layers or ridges of till | Moraines |
Moraines produced by alpine glaciers | Lateral moraineMedial moraine |
Smooth, elongated, parallel hillsSteep side faces the direction from which the ice advancedOccur in clusters called drumlin fieldsFormation not fully understood | Drumlins |
Often pockmarded with depressions called | Kettles |
Four major stages recognized in North America | NebraskanKansanIllinoianWisconsinan |