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18 Cards in this Set
- Front
- Back
Within a glacier, what is the primary force driving its motion?
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gravity
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What does sea level change have to do with past glaciations?
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glaciations greatly affect sea level and the amount of fresh water in the ocean
When glaciers become smaller and melt, sea level rises |
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What kinds of continental glacier features have been left in Indiana, especially as the glaciation receded
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Recessional or terminal moraines
Glacial Till U shaped valleys Glacial erratic (big random rocks) |
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Landscape Features of Continental Ice Sheets
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Ice sheet
Till Ice shelf polished surface |
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Evidence Left Behind by Glaciers
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Glaciers carve into land and deposit sediment
U shaped valleys Striations Glacial erratic (big random rocks) |
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zone of accumulation
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Glacier forms where accumulation of snow and ice exceeds the amount lost due to melting and other processes
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A little south of zone of accumulation
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Glacier loses ice and snow by melting, wind erosion, and sublimation
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Equilibrium line:
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The losses of ice and snow exactly balance the amount of accumulation
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Zone of ablation
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south of equilibrium:
ice melts away faster than it can be replenished, causes the glacier to end or terminate |
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What conditions are needed for the terminus of a glacier
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ice melts away faster than it can be replenished
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glacier colors
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White high up
Blue low down, blue ice in zone of ablation |
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Sublimation:
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solid going directly to vapor
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Lateral Morane
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Forms along the side of the glacier and is expressed as a dark fringe along the edge of the glacier. When the glacier melts, they form low ridges along the edges of the valley
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Moraine
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seidment edposited by a glacier over the edges and the base
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Medial Moraine
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Sediment rich belt in the center of the glacier, represents where two glaciers joined, trapping their lateral moraines within the combined glaciers
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Terminal Moraine
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Forms at termination of glacier, marks glacier's furthers downhill extent, large and conspicuous
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Glacial erratics and striations evidence of past glaciers
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They show that glaciers were present because they are the only things large enough to move erratics and create straitions draging such large sediment
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Glacial Till
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accumulate as glaciers move, they pick up and carry sediment
accumulates in piles, sheets, and ridges forming landforms called moraines |