Cold Environments

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Cold Environments
The location of cold environments &
why they are cold
Cold environments are found all across the world. They are categorised into polar glacial
regions, tundra regions and alpine areas.
Glacial areas are areas with high latitude. Usually between 60 and 90° latitude. In areas
that have a high latitude it is cooler because of the curvature of the earth. At high latitudes
there is the same amount of infra-red radiation from the sun but it is spread across a larger
area. This means that less of the radiation is absorbed in an area, therefore it isn't warmed
as much. There is also a thicker layer of atmosphere for the infra-red radiation to travel
through before it reaches the earth's surface. This means there is less of the radiation left
to heat the ground when it reaches it. As a result the surface temperature in glacial regions
can reach a minimum of -50°C. Examples of glacial areas include Antarctica and the
Arctic.
Alpine areas are areas found at high altitudes. As you increase in height from sea the air
becomes thinner. There is also less surface area of the land. This means level that less of
the infra-red radiation can be absorbed. As a result the temperature isn't increased as
much. Alpine areas are seasonal, meaning that there is a fluctuation in the annual
temperatures. In winter the temperature in alpine areas is about -10°C, but in summer the
temperatures are much higher, often exceeding 20°C. Alpine areas are usually in the
northern hemisphere. Examples include the Rockies and the Alps. There are some in the
southern hemisphere, for example the Andes.
Tundra regions are found on the edge of glacial areas. They have a permafrost, meaning
that the ground is permanently frozen. They tend to be found in mostly in the northern
hemisphere. Unlike glacial areas the tundra is not permanently covered in ice. To have a
permafrost the temperatures have to be below 0°C for 2 years. There is an active layer on
the surface of the ground which thaws in the brief summer. Tundra areas are found in
parts of Canada, Siberia and Greenland.

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Ice formation
For glaciers and ice sheets to form there must be a year-round thick mass of snow which is
compacted to form glacial ice. The snow that will make up the glacial ice undergoes a
sequence of conversion stages:
1. Snow accumulates over about a year. It has a loose granular consistency.
2. Next nivation occurs. The annual and diurnal temperature change leads to a
freeze-thaw effect. This allows the ice crystals to compact slightly.
3. The next stage is fern or nerve.…read more

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Factors controlling ice flow
Gravity
Gravity is the downhill force that encourages ice to move. It controls the direction of the
flow (downwards). The steeper a slope is, the stronger the pull of gravity is.
Friction
For the ice to move it must overcome the force of friction between it and the base. The less
friction you get the faster the glacier will move. The more friction you get, the less the
glacier will move.…read more

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Positive budget
A positive glacial budget is when the amount of accumulation exceeds the amount of
ablation. You get a positive budget in winter months when it is colder. When the glacial
budget is positive the glacier gets larger and the snout advances down the valley.
Negative budget
A negative glacial budget is where the amount ablation exceeds the amount of
accumulation. You get a negative balance in summer months when the weather is
warmer so you get more melting.…read more

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Glacial retreat
You get glacial retreat when the zone of abration exceeds the zone of accumulation. The
glacial budget is negative. There will be higher temperatures and a low level of
precipitation. This means there will be a smaller input as there is less snowfall. The high
temperature means that there will be a larger amount of ablation. As a result the volume of
the glacier will decrease and the snout of the glacier will retreat back up the valley.…read more

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Then in winter they get a large amount of accumulation so over a year the snout of the
glacier will both advance and retreat.
Weathering and associated landforms
Freeze-thaw action/ frost shattering
Freeze-thaw action is when surfaces like rocks get weathered by repeated freezing and
thawing of ice. During times of cold weather, water which had previously got into a crack in
a rock will freeze. This happens in winter but also a night. This is the diurnal and annual
temperature changes.…read more

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An example of a corrie
containing a tarn is Red Tarn in the Lake District.
Formation
1. A hollow is deepened by nivation, the combined effects of repeated freeze-thaw
weathering and the sediment is removed by the meltwater when the snow melts.
2. As ice starts accumulating in the hallow it begins to rotate due to the overlaying
pressure.
3. Plucking of the back wall causes the back wall to steepen and abrasion causes the
hole to deepen.
4.…read more

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Formation
1. Firstly a corrie glacier leaves its source and descends down an old v-shaped valley
previously carves by a river.
2. As it travels down it erodes the valley through scouring. This process involves frocks
being plucked from the base and then used to erode the base be abrasion. This
deepens and widens the valley
3. Then once the ice has melted it reveals a steep sided valley.…read more

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Fjord
A fjord is a large open lake, filled with saltwater from the sea. It is surrounded by steep
cliffs. The shape of the ground below it however will be fairly flat as it has formed at the
bottom of a U-shaped valley.
Formation
1. A valley glacier flows across the land towards the sea.
2. As the ice moves it erodes the base through scouring and abrasion.
3.…read more

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Subglacial and supraglacial streams
Fluvioglacial landforms are created by meltwater from glaciers, largely through deposition
but also through erosion. Glaciers in temperate areas in particular loose a great deal of
water to abrasion in the summer months. The meltwater forms both subglacial and
supraglacial streams. Subglacial streams flow beneath the glacier, cutting into the ice
above to form a tunnel. Supraglacial streams flow over the surface of the glacier and in
most the water descends through moulins to the base.…read more

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