|
Site Search
Advertising
Most Popular
Google Maps
Satellite Images
US Geology & Maps
|
Home »
Articles » Retreat of Alaska Glaciers
Retreat of Alaska Glaciers
Republished from a USGS news release from October 6, 2008
Most glaciers in every mountain range and island group in Alaska are experiencing significant retreat, thinning or stagnation, especially glaciers at lower elevations. In places, these changes began as early as the middle of the 18th century. The photos below document the retreat of the Muir Glacier in Glacier Bay National Monument, Alaska.
| This August 1941 photograph is of Muir Glacier in Glacier Bay National Monument, Alaska. It shows the lower reaches of Muir Glacier, then a large, tidewater calving valley glacier and its tributary, Riggs Glacier. For nearly two centuries before 1941, Muir Glacier had been retreating. In places, a thickness of more than two-thirds of a mile of ice had been lost. Photo courtesy of the National Snow and Ice Data Center and Glacier Bay National Park and Preserve Archive.
|
| This August 1950 photo documents the significant changes that occurred during the 9 years between photographs A and B. Muir Glacier has retreated more than 2 miles, exposing Muir Inlet, and thinned 340 feet or more. However, it still is connected with tributary Riggs Glacier. Photo courtesy of the Glacier Bay National Park and Preserve Archive.
|
| This August 2004 photo further documents the significant changes that have occurred during the 63 years between photographs A and C, and during the 54 years between photographs B and C. Muir Glacier has retreated out of the field of view and is now nearly 5 miles to the northwest. Riggs Glacier has retreated as much as 2000 ft and thinned by more than 800 feet. Note the dense vegetation that has developed. Also note the correlation between Muir Glacier's 1941 thickness and the nearly horizontal line on the mountainside on the left side of the 2004 photograph. This line that indicates the past height of the glacier is called a trimline. Photo courtesy of Bruce Molnia, USGS).
|
More information on glacier retreat can be found at the National Snow and Ice Data Center. USGS has a satellite image atlas of Alaska glaciers posted as a .pdf document on their website.
Most Popular From Geology.com |
|
|
|
|
|
|
Bakken Formation Oil: A USGS assessment finds lots of undiscovered oil resources in Montana and North Dakota. |
|
Redoubt Volcano: USGS/AVO photos of the 1989-90 eruption of Redoubt Volcano, Alaska. Image by C. Neal, USGS. |
|
|
|
