Glacial Erosion Processes

Question 1

Plucking.

Answer 1

This involves meltwater at the base of the glacier getting into cracks in the rock and then refreezing, as it does so it freezes to the rock.
As the glacier moves away it will pull out chunks of rock (they will be entrained).

Question 2

Abrasion.

Answer 2

This is the sandpapering effect of the glaciers load scratching, scraping and polishing as it moves over the land. The rate of this process depends on the amount and type of the glaciers load, the resistance of the rock being eroded and the speed of the traveling glacier.

Question 3

Nivation.

Answer 3

This is one of the first processes to operate at the onset of the glacier. It is a collective term for a number of processes operating under a snow patch.

These processes include: chemical action, meltwater activity and frost action.

Question 4

Freeze thaw

Answer 4

This involves meltwater getting into cracks, freezing and in doing so expanding. This expansion puts the rock under stress and after many freeze thaw cycles it may crack.