How do glaciers form hills and plains?
Glaciers are made up of fallen snow that over many, many years becomes compressed into thickened ice masses. When this becomes too heavy, gravity causes the ice to flow very slowly, and the action of the ice cuts out plains and hills whilst travelling, picking up all the rock and other material in its way. The power of the ice cuts out softer material and grinds on the harder stuff. And land is shaped in this way.
