Describe the processes responsible for ice movements. (20)Explain what factors influence the rate of glacier ice movement. (25)

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describe the processes responsible for ice movements. (20)

Explain what factors influence the rate of glacier ice movement. (25)

A. Describe the processes responsible for ice movements. (20)

There are three main processes which are responsible for ice movements, these are; Internal deformation, basal sliding and subglacial bed deformation.

Basal sliding this is the process by which a warm based glacier undergoes thawing at its base. This is due to the melting point of the ice being lowered by increased pressure and friction caused by the ice. This in turn causes the accumulation of a thin film of water along the subglacial base. A part of basal sliding is ice creep, Ice creep is where the ice flows around or over obstacles on the bed. The subglacial surface is often rough and full of obstacles such as areas of resistant rock. When a glacier meets an obstacle on the bed it does not often flow straight over or around the obstacle, there is a slight pause before the ice negotiates the obstacle. The reason for the pause is because the obstacle protruding into the base of the ice mass causes an increase in pressure within the