Gannett Glacier
Encyclopedia
Gannett Glacier is the largest glacier
in the Rocky Mountains
within the United States
. The glacier is located on the east and north slopes of Gannett Peak
, the highest mountain in Wyoming
on the east side of the Continental Divide
in the Wind River Range
. Gannett is but one of dozens of glaciers located in the Fitzpatrick Wilderness
of Shoshone National Forest
.
As is true with most glaciers around the world, Gannett Glacier is slowly disappearing. Photographic
evidence clearly demonstrates that there has been an enormous reduction in the area of the glacier since the 1920s. The area of the glacier was estimated in 1950 to be 4.6 square kilometres (1,137 acre) and was measured in 1999 to be 3.63 square kilometres (897 acre). Measurements taken in 1958 and again in 1983 showed a depth reduction of 18.6 metres (61 ft) over 25 years. A general warming pattern and a reduction in moisture is widely believed to be the reason for the glacier retreating
. Numerous other glaciers are located in the immediate area including six more that are within the top ten in size within the Rocky Mountains of the U.S.
In a 1989 study, both Gannett and Dinwoody
glaciers were researched to determine the amount of melt water they supplied to streams. Both glaciers supply melt water which flows into Dinwoody Creek, which in turn flows into the Wind River
. The melt water was found to have contributed increasingly lower amounts to the total water supplied to Dinwoody Creek. This has been attributed to the glaciers thinning and retreating, especially since 1950, when Gannett Glacier was measured to be almost 20 percent larger than in 1999. The impact on reduced stream flow from Gannett Glacier due to glacial retreat affects more than just the amount of water available for the local ecosystem and downstream agricultural and ranching interests.
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
in the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
within the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. The glacier is located on the east and north slopes of Gannett Peak
Gannett Peak
Gannett Peak is the highest peak in the U.S. state of Wyoming and straddles the boundary between Fremont and Sublette Counties along the Continental Divide.- Overview :...
, the highest mountain in Wyoming
Wyoming
Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
on the east side of the Continental Divide
Continental Divide
The Continental Divide of the Americas, or merely the Continental Gulf of Division or Great Divide, is the name given to the principal, and largely mountainous, hydrological divide of the Americas that separates the watersheds that drain into the Pacific Ocean from those river systems that drain...
in the Wind River Range
Wind River Range
The Wind River Range , is a mountain range of the Rocky Mountains in western Wyoming in the United States. The range runs roughly NW-SE for approximately 100 miles . The Continental Divide follows the crest of the range and includes Gannett Peak, which at 13,804 feet , is the highest peak...
. Gannett is but one of dozens of glaciers located in the Fitzpatrick Wilderness
Fitzpatrick Wilderness
The Fitzpatrick Wilderness is located in Shoshone National Forest in the U.S. state of Wyoming. The wilderness was originally known as the Glacier Primitive Area, but was redesignated a wilderness in 1976....
of Shoshone National Forest
Shoshone National Forest
Shoshone National Forest is the first federally protected National Forest in the United States and covers nearly 2.5 million acres in the state of Wyoming. Originally a part of the Yellowstone Timberland Reserve, the forest was created by an act of Congress and signed into law by U.S....
.
As is true with most glaciers around the world, Gannett Glacier is slowly disappearing. Photographic
Photography
Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
evidence clearly demonstrates that there has been an enormous reduction in the area of the glacier since the 1920s. The area of the glacier was estimated in 1950 to be 4.6 square kilometres (1,137 acre) and was measured in 1999 to be 3.63 square kilometres (897 acre). Measurements taken in 1958 and again in 1983 showed a depth reduction of 18.6 metres (61 ft) over 25 years. A general warming pattern and a reduction in moisture is widely believed to be the reason for the glacier retreating
Retreat of glaciers since 1850
The retreat of glaciers since 1850 affects the availability of fresh water for irrigation and domestic use, mountain recreation, animals and plants that depend on glacier-melt, and in the longer term, the level of the oceans...
. Numerous other glaciers are located in the immediate area including six more that are within the top ten in size within the Rocky Mountains of the U.S.
In a 1989 study, both Gannett and Dinwoody
Dinwoody Glacier
Dinwoody Glacier is located in Shoshone National Forest, in the U.S. state of Wyoming on the east side of the Continental Divide in the Wind River Range. Completely within the Fitzpatrick Wilderness, Dinwoody Glacier is one of the largest glaciers in the American Rocky Mountains, and as of 1989 was...
glaciers were researched to determine the amount of melt water they supplied to streams. Both glaciers supply melt water which flows into Dinwoody Creek, which in turn flows into the Wind River
Wind River
Wind River may refer to:One of several rivers in the United States:*Wind River *Wind River , a designated National Wild and Scenic River*Wind River , called in Inuit Gui-guok-lok*Wind River...
. The melt water was found to have contributed increasingly lower amounts to the total water supplied to Dinwoody Creek. This has been attributed to the glaciers thinning and retreating, especially since 1950, when Gannett Glacier was measured to be almost 20 percent larger than in 1999. The impact on reduced stream flow from Gannett Glacier due to glacial retreat affects more than just the amount of water available for the local ecosystem and downstream agricultural and ranching interests.