Mendenhall Glacier () is a

glacier A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

about long located in Mendenhall Valley, about from downtown

Juneau Juneau ( ; ), officially the City and Borough of Juneau, is the capital of the U.S. state of Alaska, located along the Gastineau Channel and the Alaskan panhandle. Juneau was named the capital of Alaska in 1906, when the government of wha ...

in the southeast area of the U.S. state of

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

. The glacier and surrounding landscape is protected as part of the Mendenhall Glacier Recreation Area, a federally designated unit of the

Tongass National Forest The Tongass National Forest () in Southeast Alaska is the largest U.S. National Forest at , an expanse larger than 10 U.S. states and 75 U.N. member nations. Most of its area is temperate rain forest and is remote enough to be home to many s ...

. The Juneau Icefield Research Program has monitored the outlet glaciers of the Juneau Icefield since 1942, including Mendenhall Glacier. The glacier has also retreated since 1929, when Mendenhall Lake was created, and over since 1500. The end of the glacier currently has a negative glacier mass balance and will continue to retreat in the foreseeable future. Given that average yearly temperatures are currently increasing, and the outlook is for this trend to continue, it is actually possible that the glacier might experience a period of stabilization or slight advance during its retreating march. This is because increasing amounts of warm, moist air will be carried up to the head of the icefield, where colder ambient temperatures will cause it to precipitate as snow. The increased amount of snow will feed the icefield, possibly enough to offset the continually increasing melting experienced at the glacier's terminus. However, this interesting phenomenon will fade away if temperatures continue to climb, since the head of the glacier will no longer have cold enough ambient temperatures to cause snow to precipitate.

Name

It was originally known as Sitaantaago ("the Glacier Behind the Town") or Aak'wtaaksit ("the Glacier Behind the Little Lake"), also Latinized as Aakwtaaksit, by the Tlingit. The glacier was named Auke (Auk) Glacier by naturalist

John Muir John Muir ( ; April 21, 1838December 24, 1914), also known as "John of the Mountains" and "Father of the national park, National Parks", was a Scottish-born American naturalist, author, environmental philosopher, botanist, zoologist, glaciologi ...

for the

Tlingit The Tlingit or Lingít ( ) are Indigenous peoples of the Pacific Northwest Coast of North America. , they constitute two of the 231 federally recognized List of Alaska Native tribal entities, Tribes of Alaska. Most Tlingit are Alaska Natives; ...

Auk Kwaan (or Aak'w Kwaan) band in 1879. In 1891 it was renamed in honor of

Thomas Corwin Mendenhall Thomas Corwin Mendenhall (October 4, 1841 – March 23, 1924) was an American autodidact physicist and meteorologist. He was the first professor hired at Ohio State University in 1873 and the superintendent of the United States Coast and Geodeti ...

. It extends from the

Juneau Icefield The Juneau Icefield is an ice field located just north of Juneau, Alaska, Juneau, Alaska, continuing north through the border with British Columbia, extending through an area of in the Coast Mountains, Coast Range ranging north to south and east ...

, its source, to Mendenhall Lake.

Flooding

Since 2011, periodic glacial floods have occurred from the Suicide Basin into the lake and downstream

Mendenhall River The Mendenhall River ( Lingít: ''Woosh Ilʼóox̱ʼu Héen'') is an Alaskan river north of Juneau in the Mendenhall Valley. The river begins at the Mendenhall Lake, at the base of the Mendenhall Glacier. Rafting on the river The Mendenhall is ...

. A major release in 2023 destroyed two buildings.

Retreat

Causes

The glacier is retreating due to a generally warming climate in Southeast Alaska, linked to

global warming Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...

driven by

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

.Flotation and retreat of a lake-calving terminus, Mendenhall Glacier, southeast Alaska, USA
'' Journal of Glaciology'', vol. 53 no. 187. 2007 The US Forest Service, which manages the Mendenhall Glacier, says "because glaciers are a product of climate, they respond to

." The Mendenhall Glacier has retreated approximately 2.5 miles since its most recent maxima during the

Little Ice Age The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region. It was not a true ice age of global extent. The term was introduced into scientific literature by François E. Matthes in 1939. Mat ...

in the mid-1700s. In a joint article for the

Juneau Empire The ''Juneau Empire'' is a newspaper in Juneau, Alaska, United States. It publishes Wednesdays and Saturdays. History The newspaper was founded on November 2, 1912, as the ''Alaska Daily Empire''. It was founded by John Franklin Alexander ...

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." It is expected the glacier face will soon pull out of the lake.

Negative effects

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. 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 Anchorage, officially the Municipality of Anchorage, is the most populous city in the U.S. state of Alaska. With a population of 291,247 at the 2020 census, it contains nearly 40 percent of the state's population. The Anchorage metropolita ...

, 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.

Benefits

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. 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.

Ancient forest uncovered

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."

Visitor center

The

United States Forest Service The United States Forest Service (USFS) is an agency within the United States Department of Agriculture, U.S. Department of Agriculture. It administers the nation's 154 United States National Forest, national forests and 20 United States Natio ...

operates the Mendenhall Glacier Visitor Center as part of the

, offering interpretive programs throughout the year for children and adults. The Mendenhall Glacier Visitor Center and surrounding area offer views of a lake-terminating, calving glacier. This was the first U.S. Forest Service visitor center built in the nation; it was designed by Linn A. Forrest and dedicated in 1962. The building was expanded, renovated and rededicated in 1999. The two small parking lots have access to several trails in the area. Photo Point Trail and the Steep Creek Trail are easy and accessible trails. Elevated boardwalks above Steep Creek provide salmon and bear viewing opportunities. Visitors can hike via the East Glacier Loop to an overlook within of the glacier. Two routes traverse a series of wooden steps and a gradual elevation gain of on this trail. The Trail of Time, which connects to East Glacier Loop, includes historical signs and handicapped accessibility. The Nugget Falls Trail leads visitors to Nugget Falls, closer to the face of the glacier.Nugget Falls Trail
– Tongass National Forest Access to the outside area and trails is free. The West Glacier trail offers access to the glacier itself and the chance to vie
ice caves
beneath it. This trail is located across the lake from the Visitor Center. In addition to the busy summer season, the center hosts the Fireside Lecture series on Friday evenings, January through March. Programs cover ecological and cultural history, and events in Southeast Alaska.

Romeo the wolf

Romeo Romeo Montague () is the male protagonist of William Shakespeare's tragedy ''Romeo and Juliet''. The son of Characters in Romeo and Juliet#Lord Montague, Lord Montague and his wife, Characters in Romeo and Juliet#Lady Montague, Lady Montague, he ...

was a wolf who lived around Mendenhall Glacier between 2003 and 2009 until he was killed by out-of-state poachers. The Visitor Center has an exhibit and

taxidermy Taxidermy is the art of preserving an animal's body by mounting (over an armature) or stuffing, for the purpose of display or study. Animals are often, but not always, portrayed in a lifelike state. The word ''taxidermy'' describes the proces ...

of Romeo's pelt to commemorate him and the town's love for him. Nick Jans' book, ''A Wolf Called Romeo'', brings Romeo's life to a broader audience.

Gallery

Mendenhall Glacier Stitch 1 June 2009 smaller

References

External links

Mendenhall Glacier, Tongass National Forest

Mendenhall Glacier Visitor Center on Twitter

{{Authority control Glaciers of Alaska Glaciers of Juneau, Alaska Protected areas of Juneau, Alaska Tongass National Forest Tourist attractions in Juneau, Alaska