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45 Cards in this Set
- Front
- Back
Glacier |
A thick mass of ice originating on land from the compaction and recrystallization of snow that shows evidence of past or present flow.
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2 Main kinds of Glacier |
-Alpine -Continental Ice Sheet |
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Alpine/Valley |
A glacier confined to a mountain valley, which in most instances had previously been a stream valley. Also know as a valley glacier. |
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Continental Ice Sheet |
A very large, thick mass of glacial ice flowing outward in all directions from one or more accumulation centers.
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Glacier Anatomy: Zone of Accumulation |
The part of a glacier characterized by snow accumulation and ice formation. Its outer limit is the snow line.
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Glacier Anatomy: Zone of Fracture |
The upper portion of a glacier, consisting of brittle ice.
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Glacier Anatomy: Zone of Wastage |
The part of a glacier beyond the sone of accumulation where all of the snow from the previous winter melts, as does some of the glacial ice.
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The work of Glaciers: Plucking |
The process by which pieces of bedrock are lifted out of place by glacier.
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The work of Glaciers: Abrasion |
The grinding and scraping of a rock surface by the friction and impact of rock particles carried by water, wind, or ice.
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Striation |
Scratches or grooves in a bedrock surface caused by the girding action of a glacier and its load of sediment.
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Landforms formed by alpine/valley glaciers: Glacial Trough |
A mountain valley that has been widened, deepened, and straightened by a glacier.
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Landforms formed by alpine/valley glaciers: Hanging Valley |
A tributary valley that enters a glacial trough at a considerable height above its floor.
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Landforms formed by alpine/valley glaciers: Cirque |
An amphitheater-shaped basin at the head of a glaciated valley produced by frost wedging and plucking.
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Landforms formed by alpine/valley glaciers: Arete |
A narrow knifelike ridge separating two adjacent glaciated valleys.
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Landforms formed by alpine/valley glaciers: Horn |
A pyramid-like peak formed by glacial action in three or more cirques surrounding a mountain summit.
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Landforms formed by alpine/valley glaciers: Fiord |
A steep-sided inlet of the sea formed when a glacial trough was partially submerged.
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Till (Glacial Drift) |
Unsorted sediment deposited directly by a glacier.
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Stratified (Glacial Drift) |
Sediments deposited by glacial meltwater. |
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Moraines |
A mass of rocks and sediment carried down and deposited by a glacier, typically as ridges at its edges or extremity. |
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4 Types of Moraines |
-Lateral (materials left as ridges after glacier wastes away)
-Medial (2 valley glaciers coalesce to form a single ice stream) -End (Ridge of till that forms at the terminus of a glacier and is characteristic of ice sheets and called glaciers alike.) -Ground (gently rolling layer of till deposited as the ice front recedes) |
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Outwash |
A relatively flat, gently sloping plain consisting of materials deposited by meltwater streams in front of the margin of an ice sheet.
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Plain |
A large area of flat land with few trees.
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Kettle |
Depressions created when blocks of ice became lodged in glacial deposits and subsequently melted.
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Kame |
A steep-sided hill composed of sand and gravel that originates when sediment is collected in openings in stagnant glacial ice.
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Drumlin |
A streamlined asymmetrical hill composed of glacial till. The steep side of the hill faces the direction from which the ice advanced. |
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Esker |
A sinuous ridge composed largely of sand and gravel deposited by a stream flowing in a tunnel beneath a glacier near its terminus.
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Pleistocene Ice Age |
An epoch of the Quaternary period beginning about 1.8 million years ago and ending about 10,000 years ago. Best known as a time of extensive continental glaciation.
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When did the Pleistocene Ice Age begin and end? |
2 million years ago/10 thousand years ago |
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Glaciations |
Long periods of cold phases. |
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Interglacials |
Short warm phases.
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Beginning and ending dates of the Pleistocene epoch |
-Began 1.8 million years ago
-Ended 10,000 years ago |
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Beginning and ending dates of the Holocene epoch |
10 thousand years ago - present |
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Leading theories about what caused the Ice Age |
-Malankovitch Cycle
-Ocean Currents |
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Deserts: How important are the roles of water, weathering, and erosion? |
Weathering- not important Water & Erosion- It doesn't rain a lot. When it does, it's heavy and a lot. There are flash floods and erosion. |
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America's Basin and Range Province |
The Basin and Range Province includes much of western North America. |
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Desert Landforms: Alluvial Fan |
A fan-shaped deposit of sediment formed when a stream's sole is abruptly reduced.
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Desert Landforms: Bajada |
An apron of sediment along a mountain front created by the coalescence of alluvial fans.
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Desert Landforms: Playa |
A flat area on the floor of an undrained desert basin. Following heavy rain, the playa becomes a lake.
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Desert Landforms: Playa Lake |
A temporary lake in a playa.
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Desert Landforms: Inselberg |
an isolated mountain remnant characteristic of the late stage of erosion in an arid region.
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Role of wind erosion in deserts |
-Deflation
-Produces: blowouts, desert pavement -Abrasion |
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Abrasion |
The grinding and scraping of a rock surface by the friction and impact of rock particles carried by water, wind, or ice.
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Deflation |
The lifting a removal of loose material by wind
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Loess |
Deposits of windblown silt, lacking visible layers, generally buff-colored, and capable of maintaining a nearly vertical cliff.
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Sand Dunes: Types |
-Barchan -Transverse -Longitudinal -Parabolic -Star (See pg. 201) |