Glaciers

Approximately 5% of Alaska (about 30,000 square miles) is covered by glaciers, which hold 3/4 of Alaska’s fresh water. Alaska’s glaciers are located primarily in the high mountain systems of Southcentral and Southeast Alaska.

These mountain ranges have the two things needed to create large glaciers: cold temperatures and lots of snow. Mountain ranges are colder than lower elevations because temperatures cool with altitude. Generally, temperatures drop approximately 3.5 degrees Fahrenheit with every 1,000 feet in altitude. So, a temperature of 50° F at sea level would be approximately 15° F at 10,000 feet. 

However, Alaska's highest and coldest mountain ranges (the Alaska and Brooks Ranges) are not where the largest glaciers are found. This is because large amounts of precipitation are also needed to create large glaciers. Alaska’s coastal mountains are located in a region where airflow from the Pacific Ocean brings in a large amount of moisture. As the moist air is pushed over the mountains (called “orographic uplift” by geographers), it is cooled and creates large snowfalls. Over thousands of years, this snowfall has created massive ice sheets in the Kenai, Chugach, St. Elias, and Coast Mountains.

Below is a short (4-minute) video on where glaciers are in the state, highlighting some of the most notable ones.

If you have trouble watching the video below, follow this link: Alaska Glaciers