Glacial Erosional Processes

Question 1

Abrasion

Answer 1

Material plucked from bedrock is frozen into the glacial ice
This material rubs against the valley side and floor
Wearing them away

Question 2

Quarrying / plucking

Answer 2

Meltwater at the base of the glacier gets into cracks in the bedrock and freezes
The ice attaches itself to the rock
As the ice moves forward, it pulls out rock
Loose rock is now found at bedrock

Question 3

Crushing

Answer 3

The weight of the overlying ice can be enough to crush bedrock that’s been weakened by Freeze thaw weathering

Question 4

Basal slip

Answer 4

Due to the pressure of overlying ice
Meltwater is present at the base of the glacier (PMP is reached)
Which leads to basal sliding
Meltwater acts a lubricant as the glacier slides over, allowing faster movement

Question 5

Sub Ariel freeze thaw weathering

Answer 5

Water gets into cracks
Freezes
Expands by about 10%
Repeated, puts pressure on the rock eventually causing it to shatter

Question 6

Mass movement

Answer 6

Sudden movement of large masses of material (avalanches, rockfall)