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12 Cards in this Set
- Front
- Back
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Soil is...
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a product of weathering rock
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Drift
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When soil is above rock when you look at big pieces of rock in drift generally contains big bowls of granite.
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Glacier process
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Loose snow fall than granular snow then firm snow then fine grained ice and then
coarse-grained ice. Gravity compacts this ice downhill. to form a glacier. |
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Glaier eqilibrium line
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No evaporation or accumulation
Low line = advancing glacier High line = retreating glacier Allows us to see wehre glaciers used to be |
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Louis Agassiz
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was aware of drifts of past. He thought that the drift generated all across eurpoe were glaciers.
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Consequences
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• 1/3 of global land area covered by sheets averaging 2 km thick.
• glaciers remove water from ocean sealevel frop of 100-130m, exposing continental shelves. • glacier growth due to global cooling; earth 5 degrees celcius colger overall. |
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Causes
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• glacial- interglacial cycles driven by variations in amount of sunlight recieved by earth
• cycles are due to minor fluctuations in shape of earths orbit • cycles operate on time scales of 10^4 to 10^5 yrs. ( so- called Milankovitch cycles). Ice has come pretty much every 100,000 years. • orbital cycles able to drive glaciations when average tem was low enough. • glaciation not common in earths time. |
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Greenhouse Effect
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• Earth’s atmosphere is transparent to incoming solar (visible) radiation but partially absorbs outgoing infrared rays
• Absorption of energy heats the air • The main absorbing component is carbon dioxide, which is on 0.035% of the atmosphere [= 350 ppm] • Burning fossil fuel carbon (coal, oil, natural gas) adds CO2 to the atmosphere • Since 1800, the CO2 level has increased by 70 ppm and the global temperature has risen about .6 degress C |
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Drift or Till
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Thin layer of soil
Bedroock |
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Moraine
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Deposit of sediment at the end of a glacier
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Milankovitch Cyles
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Ice age cycles that operate every 100,000 years
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Visible light range
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100 to 1000 nm
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