Periglacial

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  • Created by: Rebecca
  • Created on: 09-05-13 18:08
Explain the PERIGLACIAL process of NIVATION
Takes place in patches of snow beneath hollows. Freeze-thaw occurs and parts of the rock break off. Meltwater carries away the debris. The hollow becomes deeper and wider. A nivation hollow is formed. This is the start of a corrie.
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Explain the PERIGLACIAL process of SOLIFLUCTION
The active layer thaws in summer. There's less friction in soil particles. Parts of the active layer move downslope. A solifluction lobe is formed.
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Explain the PERIGLACIAL process of FROST HEAVE
Stones have a low specific heat capacity. Cold from the frozen surface passes through the stones faster than surrounding material. An ice lens forms under the stone which expands and pushes the stone to the surface. Patterned ground is formed.
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Explain the formation of ICE WEDGES in PERIGLACIAL conditions
The ground contracts in cold temperatures. Cracks form in the permafrost. In spring, meltwater seeps into the cracks. Frost contraction re-occurs and each time the ice wedge expands by around 9%.
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Explain the formation of OPEN-SYSTEM PINGOS in PERIGLACIAL conditions
Associated with discontinuous permafrost. Groundwater's forced up through gaps between permafrost. The water freezes and expands underground. This pushes up the surface.
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Explain the formation of CLOSED-SYSTEM PINGOS in PERIGLACIAL conditions
Associated with continuous permafrost. A lake on the surface insulates the ground. When it dries up, permafrost advances around the unfrozen area. Water collects and creates an ice core. If the core thaws, the pingo collapses.
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What is a fragile environment?
Natural environments where processes operate slowly and where ecosystems can be easily harmed and take a long time to recover.
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Give 3 physical and 3 human factors that contribute towards river flooding
PHYSICAL (impermeable rocks, steep slopes, high drainage density, snowmelt, intense/prolonged rainfall). HUMAN (impermeable surfaces, deforestation, agriculture, ineffective flood management/warning systems)
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What are arcuate and bird's foot types of?
Deltas
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Explain the process of rejuvenation
When the base level of a river is lowered, either by crustal uplift or a fall in sea level, the river rejuvenates. The drop in base level gives the river greater potential energy which increases vertical erosion (knick point on long profile).
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What happens to employment as you move away from the inner city to rural areas?
INNER CITY: students, unemployed and unskilled. SUBURBS/RURAL/URBAN FRINGE: tertiary sector employment. RURAL: professional, managerial, agricultural workers.
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Why can fuelwood gathering damage the environment?
Deforestation, Habitat loss, Soil erosion
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Describe the UK's energy mix.
40% gas, 33% oil, 17% coal, 2% renewable
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Define internal deformation.
The movement of ice crystals within a glacier in response to gravity and mass. Main movement in cold-based glaciers.
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Other cards in this set

Card 2

Front

Explain the PERIGLACIAL process of SOLIFLUCTION

Back

The active layer thaws in summer. There's less friction in soil particles. Parts of the active layer move downslope. A solifluction lobe is formed.

Card 3

Front

Explain the PERIGLACIAL process of FROST HEAVE

Back

Preview of the front of card 3

Card 4

Front

Explain the formation of ICE WEDGES in PERIGLACIAL conditions

Back

Preview of the front of card 4

Card 5

Front

Explain the formation of OPEN-SYSTEM PINGOS in PERIGLACIAL conditions

Back

Preview of the front of card 5
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