Cold Environments-Notes on the whole topic!

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What processes and factors give cold environments their distinctive
Characteristics in cold environments result of climatic & geomorphological processes.
The conditions of cold environments
Three sub-divisions of cold environments...
1. GLACIAL(or polar)
Glacial environments contain snow/ice all year round. Polar climates are
very cold and relatively dry.
Antarctic temperatures are an example-LOW all year round (varying from
-60ºC on ice sheet to -10ºC on the coastline). Winter temperatures vary
between -70ºC to-25ºC & summer temperatures vary from -40ºC to -2ºC.
Considerable variation in the amount of precipitation-Cold mountain winds
(katabatic winds) blow out from the centre of Antarctica to the edge of
continent. These winds form as a result of dense, cold air over the central
plateau drains into valleys.
Significant cover of snow/ice, BUT not all year round.
Found in areas of high altitude or high latitude.
This type of cold environment has large temperature ranges.
Temperatures in calm, clear weather may fall to -50ºC although spring
temperatures rise above freezing. In summer, temperatures may rise to
over 20ºC.
These areas are cold due to:
High Latitude=They receive a relatively small amount of insolation due to
the low angle of overhead sun.
High Altitude=Temperatures decline on average 1C for every 100m
Albedo=Reflection of solar radiation (av absorption is 40%; dark soils 90%
and on snow/ice is 10-20%)
Precipitation levels-generally low.
This is due to low air temperatures-cold air is only able to hold small amounts of
Many periglacial areas are affected by high pressure conditions that reduce the
amount of rainfall.
3. MOUNTAIN (upland)
Areas which were once covered in ice-now free from both snow/ice.
Landforms that were produced during cold periods continue to influence
lives of people who live in these areas.

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Most upland areas PERIGLACIAL, but not always!
Alps & Himalayas are so high that they contain glaciers and ice caps.
Mountainous areas are:
Cool-loss of about 1C for every 100m.
Wet-relief/orographic rainfall (air forced to rise over high
ground-cools, condensation occurs and precipitation is produced).
Processes in glacial environments
Glaciers-`rivers of ice'-they carry out erosion, transport and deposition.…read more

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Freeze-thaw expands and contracts joints.
Chemical weathering below
CHEMICAL WEATHERING glaciers-important-carbonate rocks
(limestones). CO2 is soluble at low
temperatures, hence meltwater streams
have capacity to hold CO2-streams become
more acidic and they are able to weather
carbonate rocks more effectively.
NB: Amount/rate of glacial erosion depends on a number of factors.
LOCAL GEOLOGY-Areas with well-fractured, jointed bedrocks are easily
VELOCITY of GLACIER-Dependent on gradient-areas of fast flowing ice leads
to increased erosion.…read more

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Mechanical stresses occur as well.
Other processes-FLUVIAL effective because of the...
Regime of the rivers (snowmelt)
The highly weathered nature of the bedrock and the nature of surface
(unconsolidated sands and gravels)
Wind action-lack of trees and disturbed nature of the ground.
Cambering is the process where segments of rock become dislodged from main
body of rock and begin to move downhill, aided by freeze-thaw.
Avalanches-type of mass movement commonly found on slopes steeper than 22º.…read more

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Very few species involved-70/8600 bird species breed in the Arctic and only
23/3200 mammals in the Arctic.
Large numbers of single species-caribou, lemmings.
Population numbers-cyclical-lemmings have a 3-7 year cycle
Periglacial environments-strongly affected by permafrost. Permafrost and low
temperatures are dominant factors in soil formation.
Bacterial activity-low and waterlogging leads to the formation of acid humus. Few
centimetres below surface blue-grey blotchy mud is found due to waterlogging.
Soils contain angular fragments of rock as a result of freeze thaw action and frost
heave.…read more

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Disturbance of permafrost-claimed to lead to irreversible changes.
Fragile tundra relies on the few species present-decline of one species will impact
on the other species. Not only are there few species but population densities are
low. Easy for native people to exterminate species over large areas.
Distinction between fragility and fluctuation-Tundra ecosystems are characterised
by large-scale oscillations eg, the Lemming cycle. It recovers from low numbers,
emphasising resilience rather than fragility.…read more

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Conflict-native herders and other land users. The Sami (reindeer herders in
Sweden) say their traditional life is in jeopardy due to owners of private forests,
using the law to exclude them from woodland.
Energy/mineral extraction-Permafrost presents many problems to engineers.
Frozen ground has great strength and when it is thawed, it becomes jelly-like
with NO strength.…read more

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