Alaska is home to more than 100,000 glaciers. Yet they only cover about 5 percent of the land area of the state. While the present-day glaciers were formed only 3,500 years ago, Alaska was covered in ice during the Pleistocene (2.588 million to 12,000 years ago). The climate then was only 3 to 9 degrees Fahrenheit colder than today.
Alaska is the northernmost sate of the U.S., located in the extreme northwest of the country and separated from the main 50 states by Canada. It borders on Russia and is partly above the polar circle. Alaska has a large land mass, but is sparsely populated. The sightseeing-friendly glaciers in Alaska are mostly found where the mountains meet the sea.
A glacier forms where more snow falls than melts away. The snow forms layers, and in the process changes to ice. After several years, an ice field forms, and when it becomes so thick it can flow down valleys, the ice field has turned into a glacier.
Glaciers collect snow and ice in higher elevations, and the ice flows downhill. When it meets the sea, it can result in the breaking off of icebergs, or calving.
Southeast Alaska is a region of high mountains, maritime climate and strong snowfall. These form ideal conditions for the formation of glaciers. The Alaskan icefields, which are the origin of the glaciers, sit atop the Coast Mountain Range on the United States-Canadian border. This is where the winds from the sea meet the mountain peaks, resulting in snowfall which exceeds 100 feet annually. The snow also does not melt in summer, due to the Alaskan climate.
The Glacier Bay national park is located in southern Alaska, near the capital of Juneau. It is only accessible by sea or air. The park is a UNESCO world heritage site. Several glaciers flow from the tall mountains of the area into the sea. The glaciers are constantly changing. While they are currently receding, the 65-mile-long fjord at the heart of the park was covered by a glacier as late as 1750.
There are several other parks with glaciers in Alaska.
Glacier viewing is a feature of most cruises to Alaska, and in summer it is possible to see icebergs calving from the glaciers, falling into the sea and generating enormous cascades of water. Glacier Park is a favorite destination of the cruise ships, due to its accessibility for large ships and the large number of glaciers there. Glacier viewing flights are also possible.
