Erosional Processes

Question 1

Abrasion

Answer 1

Scratches on bedrock.
Sediment beneath/at the side of a glacier scratching/scrapping bedrock causing striations.
Acts like ‘sandpaper’

Question 2

Quarrying/plucking

Answer 2

Rocks frozen to a glacier.

Glacier meets an obstacle, PMP decreases, so water flows over top, PMP increases, now obstacle is frozen to the glacier.

Question 3

Crushing

Answer 3

Creates ‘rock flour’

Crumbled rock which is formed by the sheer pressure of glacier ice.

Question 4

Basal melting

Answer 4

When PMP decreases, it creates meltwater at bottom of glacier, which leads to erosion.
Can cause attrition, when angular rocks become smooth.

Question 5

Freeze Thaw Weathering

Answer 5

Crack in a rock means water enters when temperatures are higher in day and freezes then expands by 9% when temperatures drop below 0%. This repeats. Rock breaks off eventually.

Question 6

Mass Movement

Answer 6

Sliding - rock/sediment falls from top to bottom of glacier.
Slumping - Only a sector of rock/sediment falls from part of glacier.
Rockfall - Dry process. rock movement
Avalanches - Cold environment process. snow/ice movement