Glaciers for Kids - What is a Valley Glacier?

In mountainous regions, a river of ice may flow down a valley. This is called a valley glacier. 

A glacier can move at different speeds, from a few inches (centimeters) every year to as much as 660 feet (200 meters) every year.
Glaciers begin in small dips or hollows on mountainsides.
Every year more snow falls into these hollows than melts.
The weight of the snow eventually squeezes the air out of the bottom layers of the snow to form ice.
Where this ice meets the rock below, pressure generates energy to melt the ice.
The melted water on the rock surface seeps into tiny cracks in the rock.
The water then freezes and expands, forcing the cracks open, allowing more water to seep in and freeze. Finally, a piece of rock breaks off.
This process is called freeze-thaw.

In the hollow, the freeze-thaw causes more pieces of rock to break away, making the hollow bigger.
The hollow is now called a cirque.
When the layer of ice becomes very heavy, it starts to flow out of the hollow and down the valley.
It is now a glacier. 
As it moves downhill, the glacier picks up tons of sand, gravel and broken rock.
These materials are deposited along the way or pushed ahead of the glacier, forming uneven ridges called moraines.
Eventually, the glacier reaches the lowlands, where the air is warm enough for the ice to melt.