Science
How do glaciers form?
A glacier forms where more snow falls each year than melts. Over decades, layers of snow pile up and compress into dense ice, which grows so heavy it slowly flows downhill like a frozen, very slow-moving river.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how glaciers works.
Step by step
- 1They form where yearly snowfall exceeds melting.
- 2Snow piles up and compresses into thick, dense ice.
- 3Under their own weight, glaciers slowly flow downhill.
- 4They carve valleys and shape landscapes over time.
Frequently asked questions
- How do glaciers form?
- Snow that doesn't fully melt builds up over years and compresses into thick ice that flows downhill.
- Do glaciers really move?
- Yes — slowly, under their own weight, sometimes only centimeters to meters per day.
- Why are glaciers important?
- They store fresh water, shape landscapes, and are key indicators of climate change.