December 23, 2024

The Shrinking Giant: A 40-Year Look at Alaska’s Mendenhall Glacier

Throughout the time spanned by the image pair, Mendenhall pulled back by about 1 mile (1.6 kilometers). In the 1984 image, the glaciers front ends at the suggestion of a popular peninsula in Mendenhall Lake. This proglacial lake gathers rain and meltwater and feeds the river flowing south through the Mendenhall Valley, a suburban area of Juneau. In the 2023 image, nevertheless, much of the glacier terminates on land and just partially reaches the lake. Thinning has also taken a toll on the glacier throughout the past four years, triggering it to narrow by about 2,000 feet (600 meters) at the bend closest to its front.
July 28, 2023
History and Impact of the Glaciers Retreat
Mendenhall Glacier began pulling away in the mid-1700s following a period of glaciation that started 3,000 years back. But in recent decades, Alaska has actually been warming twice as quick as the rest of the United States, helping to push the areas glaciers into a particularly high decrease. The Juneau Icefield, of which Mendenhall Glacier is a part, lost 63 out of 1,050 little glaciers inventoried between 2005 and 2019. Throughout that same duration, the icefield lost 10 percent of its glacier location.
Outburst Floods and Environmental Impact
The 2023 satellite images, at the top of this page and the wide-view above, were acquired on July 28, one week before a glacial outburst flood. As soon as signed up with Mendenhall at the glaciers edge, meltwater gathers in a basin where a tributary glacier. This basin can suddenly drain pipes, flooding the lake and river. Outburst floods have actually been happening here every year since 2011. On August 5, 2023, gauge information revealed record-high lake levels, producing a torrent of water that destroyed homes and displaced homeowners along the river.
Picture of Mendenhall Glacier taken in July 2022.
NASA Earth Observatory images by Wanmei Liang, using Landsat information from the U.S. Geological Survey. Story by Kathryn Hansen with science review by Christopher Shuman/UMBC/NASA GSFC.

Satellite image of Mendenhall Glacier captured on August 17, 1984, by the Thematic Mapper on Landsat 5.
Satellite picture of Mendenhall Glacier recorded on July 28, 2023, by the Operational Land Imager on Landsat 8.
Mendenhall Glacier is a popular tourist destination near Juneau, but each year there is less of it to see.
Each year, numerous thousands of individuals visit Mendenhall Glacier– a quickly available glacier near Juneau in Southeast Alaska. However each year, there is less and less of the glacier to see.
Satellite Imagery Comparison: 1984 vs. 2023
These satellite images reveal the glacier during summertime in 1984 (upper) and 2023 (lower). Snow and ice are blue in these false-color images, which blend infrared and visible wavelengths to better distinguish locations of rock, ice, and greenery. Incorrect color likewise enables a better color match in between the two images that were gathered by different satellite sensors. The 1984 and 2023 images were acquired by the Thematic Mapper on Landsat 5 and the Operational Land Imager (OLI) on Landsat 8, respectively.

These satellite images show the glacier during summertime in 1984 (upper) and 2023 (lower). In the 1984 image, the glaciers front ends at the pointer of a popular peninsula in Mendenhall Lake. Mendenhall Glacier started pulling away in the mid-1700s following a period of glaciation that began 3,000 years earlier. The Juneau Icefield, of which Mendenhall Glacier is a part, lost 63 out of 1,050 small glaciers inventoried in between 2005 and 2019. Meltwater gathers in a basin where a tributary glacier when joined Mendenhall at the glaciers edge.