How does ice cause erosion?
Ice causes erosion by a method known as freeze-thaw weathering.
When water gets into cracks in rock, during periods of cold weather, the water in the cracks freezes, and this weakens the rock, because the water expands when it freezes.
This means that the ice makes the cracks in the rock bigger, because of the expansion of the water due to freezing. Over a period of time. the cracks in the rock increase in size, and this can cause the rock to weaken.