Mendenhall Glacier

The glacier is retreating due to a generally warming climate in Southeast Alaska, linked to global warming driven by climate change.[10] The US Forest Service, which manages the Mendenhall Glacier, says "because glaciers are a product of climate, they respond to climate change."[11] The Mendenhall Glacier has retreated approximately 2.5 miles since its most recent maxima during the Little Ice Age in the mid-1700s.[12] In a joint article for the Juneau Empire Geologist Cathy Connor and Geophysicist Roman Motyka, both professors of the University of Alaska said "climatic warming coupled with ice loss through iceberg calving are the reasons the Mendenhall Glacier is retreating and shrinking."[13] It is expected the glacier face will soon pull out of the lake.

The Glacier in March, 1953
Stroller White Mountain in background

The retreat of the Mendenhall Glacier and other glaciers in the area is believed by some to be a result of broader retreat and breakup of the Juneau Icefield. The Juneau Icefield is the fifth largest icefield in North America.[14] Many populations near glacial areas rely on the glaciers for fresh drinking water. Once these glaciers are gone these people will need another source. For example, Anchorage, the most populated city in Alaska and many people there rely on the Eklutna glacier for their freshwater. If the recession of this glacier continues they will be out of their main source of water.[15][16]

Seamen from the USS Rombach exploring the glacier in March 1953.

Although there are many negative effects of the recession of the Mendenhall Glacier and glaciers in general, there are also a few positive outcomes. With the retreat of the Mendenhall Glacier, the Mendenhall Lake has formed. The lake is a result of the run-off from the glacier and is increasing in size as the glacier continues to retreat. The lake began to form in 1929 and has continued to grow.[17] The lake has a unique ecosystem and is a nursery for a variety of fish including several type of salmon, Dolly Varden, char, and cutthroat trout.[18][19]

In 2012, tree stumps and logs with attached roots and bark appeared under the retreating glacier. They are in their original growth position, preserved under what was believed to be a protective gravel layer. By uncovering them, scientists learn about the ecosystem from before the glacier formed. They can determine trees' ages when they died by looking at their preserved remains. One of the scientists, Cathy Conner, was reported as finding "The most recent stumps emerging from the Mendenhall are between 1,400 and 1,200 years old. The oldest are around 2,350 years old. Some have dated around 1,870 to 2,000 years old."[15][20]