Types of glacial erosion

There are 2 main types of glacial erosion:

1) Abrasion
2) Plucking

1. Abrasion

Definition= Sediment embedded in the base and sides of the glacier scours the solid bedrock in the valley occupied by the glacier (like sandpaper)

Factors affecting the rate of abrasion:

1) Supply of debris (supplied bu freeze-thaw weathering or picked up by plucking)
2) Relative hardness of debris and bedrock (more resistant bedrocks e.g granite decrease the rate and less resistant rocks e.g limestone increase the rate)
3) Speed of glacier movement
4) Ice thickness
5) Shape of debris (smooth/angular)

2. Plucking

Definition= when meltwater exploits pre-existing fractures/joints in the bedrock. Meltwater runs into cracks freezes the rock onto the glacier. As the glacier moves, the block is taken with it.