How do glaciers form and move?
How glaciers form: Glaciers are created in areas where the air temperature never gets warm enough to completely melt snow. After a snowfall, some or most of the snow may melt when it comes into contact with warmer ground temperatures. As the air temperature drops, the melted snow refreezes, turning into small ice granules called firn or névé (pronounced nay-VAY). As additional layers of snow accumulate on top, the firn underneath is compacted. When the accumulation reaches about 150 feet (46 meters) deep, the weight and pressure cause the lower layers to recrystallize into solid ice. As years pass, snow accumulates and the slab of ice grows steadily thicker. Eventually the mound of ice becomes too massive to sit still, and gravity pulls the ice downhill. Once the ice begins to move, it is considered a glacier. How Glaciers move: Glaciers are gigantic, solid “rivers” of ice. They have been around for much of earth’s history, and are responsible for large geographic features on its surfa
