Ice movement

Cold based glaciers (POLAR) occur in the high Latitudes where the temperature of the snow fall is far below zero degrees and the ice of the glacier remains at below zero throughout the year. These glaciers therefore stay frozen to the bedrock all year and there fore there is little ice movement and therefore little erosion. Greenland and the Antarctic have cold based glaciers.

Warm based glaciers or temperate glaciers have water present throughout the ice mass and this water acts as a lubricant. This may be for a period of the year or all year, and allows for much greater rates of movement and thus more erosion. These glaciers are often found in mountain glaciers at lower latitudes but higher altitudes than polar glaciers.

Cold based glaciers move mainly by internal deformation. These glaciers are frozen to the bed and therefore only move 1-2cm a day. The ice crystals within the glacier orientate themselves in the direction of ice movement. This allows ice crystals to slide past one another. Where the ice movement is fast enough crevasses may develop.
Temperate glaciers move mainly through BASAL SLIPPAGE. If the glacier moves, this can raise the temperature of the base ice through pressure and friction. The basal ice can then melt, and this water helps to allow the ice to slip more easily over its bed. This could move at 2-3m per day and pick up material with which it can use to erode its bed. This is related to regelation, which is the phenomenon of