What is a glacier?
Glaciers are slow moving bodies of ice that form from the mass compression of snow over hundreds of years. Physically, glaciers behave very similar to rivers, which is why glaciers are often termed "rivers of ice." As glaciers advance, they engulf everything in their path, grind it up, forming glacial silt at the toe of the glacier. Many valley's and lakes have been carved out by glaciers around the world; including parts of Alaska and the Pacific Northwest.
How are glaciers formed?
When snow accumulates in the same location, year after year, glaciers tend to form and advance. These areas are generally at higher altitudes because temperatures need to remain cool, so snow is less likely to melt. As the snow accrues, it compresses, which forces the snow to re-crystallizes into ice forming glaciers.
Types of Alaskan Glaciers
The most common type of glaciers found in Alaska are mountain glaciers, due to our numerous mountain ranges. Other types of glaciers are piedmont, hanging and tidewater glaciers.