Examine the factors influencing the movement of glaciers.

Examine the factors influencing the movement of glaciers. Glacier is defined as, 'a mass or river of ice moving very slowly'. Glaciers range in size considerably, Antarctica being the largest ice mass at 12.5 million km and a smaller ice mass of 12km existing in Africa. Glaciers move due to the force of gravity from areas of high altitude to lower areas. There are different mechanisms of glacial movement depending on the type of glacier. Cold (polar) glaciers are frozen to the underlying rock surface. These are found in high-latitude locations where the relief is low and basal temperatures are below the pressure melting point. Cold glaciers have very slow rates of movement, e.g. The Meserve glacier in Antarctica moves only 3-4 metres per year. Warm (temperate) glaciers on the other hand are not frozen to their bed. This type of glacier is found in high-altitude locations where the relief is steep and basal temperatures are at or near the pressure melting point. Temperate glaciers move very rapidly, e.g. The Franz Josef glacier in New Zealand moves approximately 300m per year. It is the basal temperature that determines the mechanism of movement. In what follows I will explain the factors influencing different mechanisms of movement. Temperate glaciers move mainly by basal sliding. If the basal temperature is at or above pressure melting point, a thin layer of meltwater

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  • Level: AS and A Level
  • Subject: Geography
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