What is a glacier? A glacier is a large mass of compacted snow and ice that moves under the force of gravity.
What are the two types? The first type of glacier is the valley glacier; which is a glacier that moves within valley walls. The second type of glacier is the continental glacier; which is a glacier that covers a large part of a continent.
How do glaciers move? They move by the slipping of the water that is being squished under all of the snow.
Why did Ice Ages occur in the past? One theory of why Ice Ages occurred is that a volcano erupted and that spread ash every where which caused less sunlight and that caused a year of cold and snow which caused glaciers.