Glaciers form over time and then change the appearance of the land by erosion.
There are two types of glacial erosion. The first is caused by continental ice sheets, and the second results from mountain glaciers. Glaciers that are on mountains are called mountain glaciers or alpine glaciers. When the glaciers erode away they form many different topographic features. There are many types of glacial erosion and one that occurs at the base of the glacier is plucking.