cold environments distinct season below freezing with snow in winter. can be defined by latitude and...
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Cold Environments
•Distinct season below freezing with snow in winter.
•Can be defined by latitude and altitude ie.~
Polar Arctic and subarctic
Periglacial Siberia
Mountain Alps
Remember how would you describe a climate graph?
Processes in Glacial Environments :~
Weathering
Mechanical•Freeze – thaw
•Wet/dry
•Pressure release
Chemical•Solution/ carbonation
•Acid action (meltwater)
•Hydrolysis
BiologicalPlants and animals in search of essentials
Ice works really well because: -•Bare rock surfaces
•Ice is solid and powerful – assisted by rivers freezing
•Amount of ice – filling river valleys – routes already provided
Erosion Processes:-
•Plucking
•Abrasion
•Bulldozing
Control over erosion:-•Speed Temperature
•Thickness of Ice Debris
•Bedrock Existing landscape
Water erosion and Deposition:-
Summer melts - Debris - Glacial melt - Permafrost
Periglacial •Active layer
•Expansion features – Pingo – congelifraction
•Mass movement – solifluction
•Seasonal rivers – braiding
•Wind action
http://www.scalloway.org.uk/phyl12e.htm
A U-shaped valley is the shape left after a valley has been overdeepened by a glacier. The original V-shaped valley, which would have been made by a river, is widened and deepened after the ice has eroded the sides and bottom of the valley. V-shaped valleys have a wide flat floor, which may contain ribbon lakes (long and narrow) and mis-fit streams (so called because they are too small to have made the valley).
The sides of U-shaped valleys may have hanging valleys, which are side valleys that are left high on the side of a main valley that has been deepened by glaciation. Streams flowing in a hanging valley may form a waterfall as it flows down the steepened sides. The valley sides may also have truncated spurs which are the ends of sloping ridges cut off (or truncated) by the valley glacier which tends to flow straighter than a river.
BBC - Learning Zone Broadband Class Clips - Mountains
http://www.scalloway.org.uk/phyl13e.htm
CorriesCorries are armchair-shaped hollows, which are found high up on the sides of hills. They are often formed on the shaded and therefore colder side of the hill. Here the snow does not melt as fast and there can be a build up of snow which is squashed and turned into ice. As the ice moves downhill it erodes the underlying rock, eventually producing a corrie. Often two or more corries are formed leaving a narrow ridge between them. This is called an arete. When a hill has been heavily eroded with 3 or 4 corries the jagged hill that is left is known as a horn or pyramidal peak.
corries video
Corrie
corrie animation
slide share
Glacial drift, boulder clay and outwash
glacial drift video
Esker
Delta and Outwash Plain
http://www.scalloway.org.uk/phyl17e.htm
Human activity and glacial deposition