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34 Cards in this Set
- Front
- Back
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a moving body of ice on land that flows downslope or outward from an area of accumulation
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glacier
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confined to mountain valleys where they flow from higher to lower elevation
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valley glacier
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vast, covering at least 50,000 km2 and are unconfined by topography
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continental glacier
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all glacial activity including the origin, expansion, and retreat of glaciers as well as their impact on earth's surface
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glaciation
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what is glacial ice composed of?
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90% solids 10% air
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partially thawed refrozen accumulated compacted snow
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firn
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a type of permanent deformation involving no fracturing
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plastic flow
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sliding over underlying surface
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basal slip
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a balance sheet of expansion and contraction in response to accumulation and wastage
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glacial budget
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addition exceed losses/ always snow covered
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zone of accumulation
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losses from melting, sublimination, and carving of icebergs exceed rate of accumulation
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zone of wastage
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a short lived episode of accelerated flow in a glacier during which its surface breaks into a maze of crevasses and its terminus advances noticeably
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glacial surge
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when glaciers shove or push unconsolidated material in its path
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bulldozing
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glacial ice freezes in the cracks and crevasses of a bedrock projection and eventually pulls it loose
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plucking
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bedrock over which sediment laden glacial ice moves is eroded and developes glacial polish and striations
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abrasion
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long, steepwalled embayments
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fiord
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a tributary valley whose floor is at a higher level than that of the main valley
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hanging valley
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steep wall/ bowl shaped depressions
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cirque
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narrow, serrated ridges
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aretes
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steep walled, pyramidal peaks formed by headward erosion of cirques
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horns
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a general term for all deposits resulting from glacial activity
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glacial drift
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rocks derived from a distance source but move with glaciers
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glacial erratics
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sediments deposited by glacial ice directly
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till drift
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layered and invariably exhibits some degree of sorting by particle size
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stratified drift
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any sediment transported within a stationary glacier that is dumped at glaciers terminus
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end moraine
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till deposited as ice melts in a later on ground
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ground moraine
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deposited till if ice front has receded
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recessional moraine
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outermost end moraine
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terminal moraine
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sediment deposited along margin
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lateral moraine
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continental glaciers deposit till in the shape of elongated hills
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drumlin
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blanket of sediment in streams flowing from glacier
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outwash plain
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long narrow deposits of stratified drift
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valley train
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conical hills of stratified drift
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kames
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long sinuous ridges of stratified drift
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esker
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