The Juneau Icefield is an
ice field
An ice field (also spelled icefield) is a mass of interconnected valley glaciers (also called mountain glaciers or alpine glaciers) on a mountain mass with protruding rock ridges or summits. They are often found in the colder climates and highe ...
located just north of
Juneau
The City and Borough of Juneau, more commonly known simply as Juneau ( ; tli, Dzánti K'ihéeni ), is the capital city of the state of Alaska. Located in the Gastineau Channel and the Alaskan panhandle, it is a unified municipality and the s ...
,
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...
, continuing north through the border with
British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...
, extending through an area of in the
Coast Range ranging north to south and east to west. The icefield is the source of many
glacier
A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such a ...
s including the
Mendenhall Glacier
Mendenhall Glacier (in Tlingit language “Sít”) is a glacier about long located in Mendenhall Valley, about from downtown Juneau in the southeast area of the U.S. state of Alaska. The glacier and surrounding landscape is protected as p ...
and the
Taku Glacier. The icefield is home to over 40 large valley glaciers and 100 smaller ones. The Icefield serves as a tourist attraction with many travellers flown in by helicopter for quick walks on the deep ice and the massive, awe-inspiring moist
crevasse
A crevasse is a deep crack, that forms in a glacier or ice sheet that can be a few inches across to over 40 feet. Crevasses form as a result of the movement and resulting stress associated with the shear stress generated when two semi-rigid p ...
s. The icefield, like many of its glaciers, reached its maximum glaciation point around 1700 and has been in retreat since. In fact, of the icefield's 19 notable glaciers, the Taku Glacier is the only one presently advancing. Much of the icefield is contained within the
Tongass National Forest
The Tongass National Forest () in Southeast Alaska is the largest U.S. National Forest at . Most of its area is temperate rain forest and is remote enough to be home to many species of endangered and rare flora and fauna. The Tongass, which is ...
. Since 1948, the Juneau Icefield Research Program has monitored glaciers of the Juneau Icefield. On the west side of the icefield, from 1946-2009, the terminus of the Mendenhall Glacier has retreated over . Eight kilometers to the north, the
Herbert Glacier has retreated , while
Eagle Glacier retreated , Gilkey Glacier and
Llewellyn Glacier
The Llewellyn Glacier is a glacier located in British Columbia and Alaska. It is the second-largest glacier in the Juneau Icefield. The glacier has rapidly retreated as of recent, and on June 6, 2018, a large kilometre-sized chunk of the narrow ...
. On the south side of the icefield, the
Norris Glacier retreated , the
East Twin Glacier , the
West Twin Glacier with only the Taku Glacier advancing. Surveys reveal the Taku as one of the deepest glaciers of the sub-temperate icefields surveyed at nearly thick.
This glacier was advancing in 1890 when viewed by
John Muir
John Muir ( ; April 21, 1838December 24, 1914), also known as "John of the Mountains" and "Father of the National Parks", was an influential Scottish-American naturalist, author, environmental philosopher, botanist, zoologist, glaciologis ...
and had a large
calving front. By 1963 the glacier had advanced . In 1948 the
Taku Fjord
Taku may refer to:
Places North America
* the Taku River, in Alaska and British Columbia
** Fort Taku, also known as Fort Durham and as Taku, a former fort of the Hudson's Bay Company near the mouth of the Taku River
** the Taku Glacier, in Al ...
had been completely filled in with glacial sediment and the glacier no longer calved. From 1948–1986 the glacier had a positive
glacier mass balance driving the advance. From 1987–2009 the glacier has had a slightly negative mass balance, not enough to end the advance, but if it continues will soon slow it.
Notable peaks on the Juneau Icefield are
Devils Paw,
Nelles Peak,
Emperor Peak,
The Snow Towers
The Snow Towers is a glaciated mountain summit located in the Boundary Ranges of the Coast Mountains, in the U.S. state of Alaska. The two peaks, 0.1 mi apart, are situated at the apex of the Taku and Herbert Glaciers near the western edge of th ...
,
Taku Towers,
Camp 15 Peak, and the
Mendenhall Towers.
See also
*
List of glaciers and icefields
*
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. Deglaciation occur ...
*
Ha-Iltzuk Icefield
*
Homathko Icefield
*
Lillooet Icecap
The Lillooet Icecap, also called the Lillooet Icefield or the Lillooet Crown, is a large icefield in the Pacific Ranges of the Coast Mountains in southwestern British Columbia, Canada. It is about northwest of the towns of Pemberton and Whis ...
Gallery
File:Juneau Ice Field (8025725933).jpg, Juneau Icefield showing Devils Paw and Nelles Peak
File:Spirit Range 1532.jpg, Spirit Range, over the Juneau Icefield
File:Juneau Ice Field (5013565995).jpg, Several prominent peaks in the icefield
File:Alamy WM 1506.jpg, Juneau Icefield looking Northwest
References
External links
Terminus Behavior of Juneau Icefield Glaciers 1948-2005Juneau Icefield Research ProgramCanadian Mountain Encyclopedia: Juneau Icefield entrycrevassezone.orgPulitzer Center Crisis ReportingJuneau Icefield Research (multimedia)
A description of the flora and fauna in the Icefield
{{Authority control
Boundary Ranges
Ice fields of Alaska
Ice fields of British Columbia
Glaciers of Juneau, Alaska
Stikine Country
Tourist attractions in Juneau, Alaska
Tongass National Forest