The Juneau Icefield or Juneau Icecap is an ice field located just north of Juneau, Alaska and continues north through the border with British Columbia and the fifth-largest ice field in the Western Hemisphere[1]. An ice field (also spelled icefield) is an area less than 50000 km² (19305 mile²) of Ice often found in the colder climates and higher altitudes Alaska ( Аляска Alyaska) is a state in the United States of America, in the northwest of the North American continent British Columbia (ˌbrɪtɨʃ kəˈlʌmbiə ( BC) ( (la Colombie-Britannique C The Western Hemisphere, also Western hemisphere or western hemisphere, is a geographical term for the half of the Earth that lies West

View of the Juneau Icefield.

The Juneau Icefield is the fifth largest icefield in North America, extending through an area of 3,900 square kilometers in the Coast Range ranging 140 km north to south and 75 km east to west. A Coastal range is any range of mountains forming a coastline The icefield is the source of a myriad of glaciers including the famous "drive-up" Mendenhall Glacier and the aggressive Taku Glacier. "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. Mendenhall Glacier is a Glacier about 12 miles (19 km long located in Mendenhall Valley, about 12 miles (19 km from downtown Juneau in the southeast Taku Glacier is a Tidewater glacier located in Taku Inlet in the U The icefield in fact 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 240 to 1,400 meter deep ice and the massive, awe-inspiring crevasses. A crevasse is a Fracture in a Glacier caused by a large Tensile stress at or near the glacier's surface The icefield, like many of its glaciers, reached its maximum glaciation point around 1700 and has been decreasing in size since. In fact, of the icefield's 19 notable glaciers, the Taku Glacier is the only one presently advancing.

Since 1948, the Juneau Icefield Research Program has monitored glaciers of the Juneau Icefield. On the west side of the icefield, from 1946-2005, the terminus of the Mendenhall Glacier has retreated 580 meters.

Locational map of major features of the Alaska Panhandle area including the Juneau Icefield in the northern portion

Eight kilometers to the north, the Herbert Glacier has retreated 540 meters, while Eagle Glacier retreated 700 meters, Gilkey Glacier 3,500 meters and Llewellyn Glacier 2,800 m. The Alaska Panhandle, sometimes referred to as Southeast Alaska, is the southeastern portion of the U On the south side of the icefield, the Norris Glacier retreated 1,740 meters, the East Twin Glacier 1,100 meters, and the West Twin Glacier 570 meters. Only the Taku Glacier has advanced. Surveys reveal the Taku as one of the deepest glaciers of the sub-temperate icefields surveyed at nearly 1,370 m thick. This glacier was advancing in 1890 when viewed by John Muir and had a large calving front. John Muir ( April 21, 1838 – December 24, 1914) was a Scottish -born American Naturalist, author and early By 1963 the glacier had advanced 5. 6 km. In 1948 the Taku Fjord had been completely filled in with glaical sediment and the glacier no longer calved. From 1948-1986 the glacier had a positive glacier mass balance driving the advance. See also Retreat of glaciers since 1850 Crucial to the survival of a Glacier is its mass balance, the difference between accumulation From 1987-2005 the glacier has had a slightly negative mass balance, not enough to end the advance, but if it continues will soon slow it.

A notable peak in the Juneau Icefield is Devils Paw. Devils Paw (or Devil's Paw, or Boundary Peak 93) is the high point of the Juneau Icefield, on the Alaska - British Columbia border

See also

• List of glaciers and icefields
• Mendenhall Glacier
• Taku Glacier
• Retreat of glaciers since 1850
• Ha-Iltzuk Icefield
• Homathko Icefield
• Lillooet Icecap

External links

• Terminus Behvaior of Juneau Icefield Glaciers 1948-2005
• Forest Service overview
• Juneau Icefield Research Program
• Canadian Mountain Encyclopedia: Juneau Icefield entry
• crevassezone.org
• More Pictures from the Juneau Icefield
• Pulitzer Center Crisis Reporting Juneau Icefield Research (multimedia)