Ice Movement; Short and Snappy 0.0 / 5 ? GeographyHot and cold environmentsASAQA Created by: jack1506Created on: 28-03-14 10:40 Internal Deformation Internal Deformation can occur in both Warm and also Cold Based Glaciers. Involves Ice Crystals Slipping and Sliding over each other. The crystals can also become deformed and fractured due to the force of gravity downhill. It usually occurs at the same time as Basal Sliding. 1 of 4 Basal Sliding Involves movement of a large block of ice In series of short jerks Meltwater forms on the upslope side of obstacles on the valley floor, which increases resistance This increases Presssure, causing localised melting of the ice Called Pressure melting Meltwater allows the ice to flow up On the other side of the obstacle it will often then refreeze the meltwater. Due to there being less pressure. 2 of 4 Extensional Flow Occurs when there is a sudden steep gradient in front of the ice The ice flows down the gradient faster and becomes thinner Overstretching in the ice results in the formation of glaciers When the ice reaches the end of the steep gradient, compressional flow begins 3 of 4 Compressional Flow A reduction in gradient slows the ice's flow The Ice then piles up at the bottom of the gradient, becoming thicker This is called Compressional Flow Crevasses opened up by extensional flow will now be closed In the centre of the gradient, rotational movement takes place This is the movement that forms Corries 4 of 4
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