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Slide 1

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Ice revision cards…read more

Slide 2

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Biggest Glaciers and Global distribution
· Antarctica- 13.5 million km²
· Greenland- 1.8 million km²
· Canada- 200,000km²
· Central Asia- 109,000km²
· Russia- 82,000km²
· Glacial Areas
­ Greenland
­ Antarctica
· Tundra
­ Russia
­ Canada
· Alpine areas
­ Andes
­ Rockies
­ Himalaya
­ Norway
­ Alps…read more

Slide 3

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Glacial and Periglacial processes
· Glacial- erosive action of glacial ice and
deposition of sediment from glaciers
· Periglacial- action of ground frost and snow
· The landscape of cold environments is
primarily shaped by glacial and Periglacial
processes…read more

Slide 4

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· Periglacial- areas on the periphery ice sheet, areas that
experience a cold climate with intense frost action and
development of permafrost
· Characteristics
­ Long cold winters <0c for 9 months
­ 6 months= <-10c
­ Autumn and spring- temp fluctuates at 0c
­ Vegetation- Tundra (treeless plains)
· Locations
­ Mountainous areas in temperate zones
­ N. America and Russia in arctic circle
­ Close to glacial conditions- Near ice sheet in Greenland
· Permafrost
­ Permanently frozen ground
­ Average soil temp below 2c for 2 years
­ Grows a few cm a year
­ 2 layers…read more

Slide 5

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· Active layer
­ Thin layer that melts in summer when summer temps rise
above freezing point
­ Surface layers thaw from the surface downward
­ Thickness of this layer depends on local conditions but may
extend down to 4
­ Melting releases large volumes of water
­ Water can't infiltrate / percolate down through the permafrost
­ Little evaporation due to low temps
­ Surface is therefore v. wet as the thawing of the "active" layer
creates boggy conditions because the unyielding frozen layer
hinders water drainage
· Base layer
­ Thick frozen ground that never melts…read more

Slide 6

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Types of Permafrost
Continuous permafrost
­ Coldest regions eg; Arctic circle
­ Mean annual temps < -5°C
­ Winter temps may fall below -50°C
­ Summers v. cold & short allowing only superficial surface
­ Reaches deep into surface layers
­ Hardly any melting of upper layers
Discontinuous permafrost
· Slightly warmer regions
· Further south in N. Hemisphere reaching 50°N in Russia
· Mean annual temps between -1°C & -5°C.
· Islands of permanently frozen ground separated by less cold
areas near rivers, lakes & seas
· Not frozen as deep: 20 ­ 30 m below ground surface down to
about 45 m
· Gaps are found in the permafrost below rivers, lakes & near sea…read more

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