12.2 Processes of Glacial Erosion As a glacier moves, it erodes the landscape by two main processes.
1. Plucking
Meltwater gathers in cracks and refreezes onto rock
As ice moves, rock is torn out and taken away
Ice 2. Glaciers can erode by plucking
As ice moves, it causes friction between the ice and the ground below. This friction creates heat, which causes the ice at the base to melt. The meltwater flows into the cracks in the rock. The water then refreezes around the rocks and sticks to the glacier. When the ice moves forward again, it can pull or pluck chunks of the rock out of the ground.
2. Abrasion
Plucked rocks become embedded in the base of the glacier. As the glacier moves, the rocks abrade (scrape and smooth) the surface over which they pass.
3. Glaciers can also erode by abrasion
Pieces of rock held in ice scrape surrounding rock
Ice
Rub your hands together. Can you feel the friction created between them?
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FUN FACT!
Seventy-five per cent of the world’s total supply of fresh water is frozen in glaciers.