Glacial erosion

Question 1

Glacial erosion

Answer 1

• Occurs at the ice-rock interface
• Ice that moves has a considerable erosive effect
• Ice-free of debris has a little erosive effect

Question 2

Processes of glacial erosion

Answer 2

1. Abrasion
2. Plucking
3. Rotational movement
4. Extending and compressing flow

Question 3

Abrasion

Answer 3

The material the glacier is carrying rubs against the valley floor + sides

• Coarser harder rocks may leave striations
• Finer debris smooths the rock surface

Question 4

Plucking

Answer 4

Glacier freezing to the back wall, as it moves = ice moves forward pulling away masses of rock

Question 5

Rotational movement

Answer 5

The ice pivoting around a central point, in a circular way

Question 6

When does maximum erosion occur?

Answer 6

• Where temps fluctuate around 0 degrees = freeze-thaw occurs
• Areas of jointed rocks which can be more easily frost shattered
• Where two tributary glaciers join, or valley narrows, giving an increased depth of ice
• In steep mountainous regions in temperate latitudes, where the velocity of the glacier is greatest.