Mendenhall Glacier
Encyclopedia
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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...
about 12 miles (19.3 km) long located in Mendenhall Valley
Mendenhall Valley
Mendenhall Valley is an area of Juneau in the U.S. state of Alaska. The valley, named for physicist and meteorologist Thomas Corwin Mendenhall, was formed by Mendenhall Glacier over the course of roughly three thousand years...
, about 12 miles (19.3 km) from downtown Juneau
Juneau, Alaska
The City and Borough of Juneau is a unified municipality located on the Gastineau Channel in the panhandle of the U.S. state of Alaska. It has been the capital of Alaska since 1906, when the government of the then-District of Alaska was moved from Sitka as dictated by the U.S. Congress in 1900...
in the southeast area of the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
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Originally known as Sitaantaagu ("the Glacier Behind the Town") or Aak'wtaaksit ("the Glacier Behind the Little Lake") by the Tlingits, the glacier was named Auke (Auk) Glacier by naturalist John Muir
John Muir
John Muir was a Scottish-born American naturalist, author, and early advocate of preservation of wilderness in the United States. His letters, essays, and books telling of his adventures in nature, especially in the Sierra Nevada mountains of California, have been read by millions...
for the Tlingit Auk Kwaan (or Aak'w Kwaan) band in 1888. In 1891 it was renamed in honor of Thomas Corwin Mendenhall
Thomas Corwin Mendenhall
Thomas Corwin Mendenhall was an autodidact US physicist and meteorologist.-Biography:Mendenhall was born in Hanoverton, Ohio to Stephen Mendenhall, a farmer and carriage-maker,...
. It extends from the Juneau Icefield
Juneau Icefield
The Juneau Icefield is an ice field located just north of Juneau, Alaska and continues north through the border with British Columbia and is the fifth-largest ice field in the Western Hemisphere, extending through an area of in the Coast Range ranging north to south and east to west. The...
, its source, to Mendenhall Lake
Mendenhall Lake
Mendenhall Lake is a lake in the Mendenhall Valley at the 1962 terminus of Mendenhall Glacier, North of the Juneau City and Borough Airport in the Coast Mountains...
and ultimately the Mendenhall River
Mendenhall River
The Mendenhall River 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:...
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The Juneau Icefield Research Program has monitored the outlet glaciers of the Juneau Icefield since 1942 , including Mendenhall Glacier. From 1951–1958 the terminus of the glacier, which flows into suburban Juneau, has retreated 1,900 feet (580 m). The glacier has also receded 1.75 miles (2.8 km) since 1958, when Mendenhall Lake was created, and over 2.5 miles (4 km) since 1500. The end of the glacier currently has a negative glacier mass balance
Glacier mass balance
Crucial to the survival of a glacier is its mass balance, the difference between accumulation and ablation . Climate change may cause variations in both temperature and snowfall, causing changes in mass balance. Changes in mass balance control a glacier's long term behavior and is the most...
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
Glacier terminus
A glacier terminus, or snout, is the end of a glacier at any given point in time. Although glaciers seem motionless to the observer, in reality glaciers are in endless motion and the glacier terminus is always either advancing or retreating...
. 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.
Visitor Center
The United States Forest ServiceUnited States Forest Service
The United States Forest Service is an agency of the United States Department of Agriculture that administers the nation's 155 national forests and 20 national grasslands, which encompass...
administers the Mendenhall Glacier Visitor Center as part of Tongass National Forest
Tongass National Forest
The Tongass National Forest in southeastern Alaska is the largest national forest in the United States at 17 million acres . Most of its area is part of the temperate rain forest WWF ecoregion, itself part of the larger Pacific temperate rain forest WWF ecoregion, and is remote enough to be home...
. US Forest Service interpreters offer conservation education programs throughout the year for children and adults. It is the only visitor center in the United States within a half mile of a terminal glacier that calves icebergs into a lake. The center is open year-round and receives close to 500,000 visitors each year, many coming by cruise ship in summer. The visitor center has two accessible entrances - an upper entrance with a ramp and a lower entrance with elevators.
This was the first US Forest Service visitor center built in the nation. Dedicated in 1962, it originally served pie and coffee in the area of the center that today shows movies to local residents and visitors. Exhibits in the Center cover the history of Mendenhall Glacier showing how it covered the valley when Joseph Whidbey
Joseph Whidbey
Joseph Whidbey was a member of the Royal Navy who served on the Vancouver Expedition 1791–1795, and later achieved renown as a naval engineer. He is notable for having been the first European to discover and chart Admiralty Island in the Alexander Archipelago in 1794.Little is recorded of...
, master of the HMS Discovery
HMS Discovery (1789)
HMS Discovery was a Royal Navy ship launched in 1789 and best known as the lead ship in George Vancouver's exploration of the west coast of North America in his famous 1791-1795 expedition. She was converted to a bomb vessel in 1798 and participated in the Battle of Copenhagen. Thereafter she...
during George Vancouver
George Vancouver
Captain George Vancouver RN was an English officer of the British Royal Navy, best known for his 1791-95 expedition, which explored and charted North America's northwestern Pacific Coast regions, including the coasts of contemporary Alaska, British Columbia, Washington and Oregon...
's 1791-95 expedition
Vancouver Expedition
The Vancouver Expedition was a four-and-a-half-year voyage of exploration and diplomacy, commanded by Captain George Vancouver. The expedition circumnavigated the globe, touched five continents and changed the course of history for the indigenous nations and several European empires and their...
, toured the area in 1794 and what is happening due to climate change today. The exhibits depict the variety of wildlife in the area including mountain goat
Mountain goat
The Mountain Goat , also known as the Rocky Mountain Goat, is a large-hoofed mammal found only in North America. Despite its vernacular name, it is not a member of Capra, the genus of true goats...
s, wolves, black bears
American black bear
The American black bear is a medium-sized bear native to North America. It is the continent's smallest and most common bear species. Black bears are omnivores, with their diets varying greatly depending on season and location. They typically live in largely forested areas, but do leave forests in...
and red salmon in the nearby streams. Forest interpreters provide tours, children's nature programs, point out wildlife and answer questions about the area.
There is a large parking lot with access to several trails in the area. Photo Point Trail and the salmon, bear and Steep Creek Trail are easy and accessible trails. Elevated boardwalks above Steep Creek provide safe bear viewing in June, July, August and September. Visitors can hike via the East Glacier Loop to an overlook within a half mile of the glacier. For the more adventurous, there is the Nugget Falls Trail that leads you to the five-story Nugget Falls
Nugget Falls
Nugget Falls, also known as Nugget Creek Falls or Mendenhall Glacier Falls, is a waterfall downstream of the Mendenhall Glacier, in the U.S. state of Alaska. Formed by the receding face of the Mendenhall Glacier, the waterfall drops in two tiers of and onto a sandbar in Mendenhall Lake, which is...
near the face of the glacier, or you can actually hike up onto the glacier via the West Glacier Trail. Access to the area and trails is free.
From May through September, there is a $3 admission fee to go into the visitor center to view the exhibits and see audio visual presentations. Activities outside the center building itself are free of charge, and visitors may use the restrooms and visit the bookstore without paying the fee. This fee provides for maintenance of the trails, programs during summer, and updating the exhibits in the center. There is no fee in the winter.
In addition to the busy summer season, the Center hosts the Fireside program series for several months in winter every Friday night. Programs cover the ecological and culture history and events in Southeast Alaska. Inside the Visitor Center is a natural and cultural history bookstore run by the Alaska Natural History Association which is a non-profit organization supporting the public lands of Alaska. Trail guides, wildlife and bird guides, children books and other materials are available here.
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See also
- GlaciologyGlaciologyGlaciology Glaciology Glaciology (from Middle French dialect (Franco-Provençal): glace, "ice"; or Latin: glacies, "frost, ice"; and Greek: λόγος, logos, "speech" lit...
- List of glaciers
- Retreat of glaciers since 1850Retreat of glaciers since 1850The 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...
- Nugget FallsNugget FallsNugget Falls, also known as Nugget Creek Falls or Mendenhall Glacier Falls, is a waterfall downstream of the Mendenhall Glacier, in the U.S. state of Alaska. Formed by the receding face of the Mendenhall Glacier, the waterfall drops in two tiers of and onto a sandbar in Mendenhall Lake, which is...