Great Bear Lake
| Great Bear Lake | |
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| On the shores of Great Bear Lake | |
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| lake map | |
| Location | Northwest Territories |
| Coordinates | 66°N 121°W / 66°N 121°WCoordinates: 66°N 121°W / 66°N 121°W |
| Primary outflows | Great Bear River |
| Catchment area | 114,717 km2 (44,292 sq mi)[1][2] |
| Basin countries | Canada |
| Surface area | 31,153 km2 (12,028 sq mi)[1][2] |
| Average depth | 71.7 m (235 ft)[1][2] |
| Max. depth | 446 m (1,463 ft)[1][2] |
| Water volume | 2,236 km3 (536 cu mi)[1][2] |
| Residence time | 124 years[1] |
| Shore length1 | 2,719 km (1,690 mi) (plus 824 km (512 mi) island shoreline)[1][2] |
| Surface elevation | 186 m (610 ft) |
| Islands | 26 main islands, totaling 759.3 km2 (293.2 sq mi) in area[1] |
| Settlements | Deline, Port Radium |
| References | [1][2] |
| 1 Shore length is not a well-defined measure. | |
Great Bear Lake (Slavey: Sahtú, French: Grand lac de l'Ours) is the largest lake entirely within Canada (Lake Superior and Lake Huron straddling the Canada-US border are larger), the fourth largest in North America, and the seventh largest in the world. The lake is in the Northwest Territories and is situated on the Arctic Circle between 65 and 67 degrees of northern latitude and between 118 and 123 degrees western longitude, 186 m (610 ft) above sea level. The name is believed to have originated with the First Nations living along the northern shores of the lake, who referred to themselves by Chipewyan words meaning “grizzly bear water people.” Grizzly Bear Mountain on the shore of the Lake comes from the Chipewyan, meaning, literally “bear large hill.”[3]
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[edit] Geography
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The lake has a surface area of 31,153 km2 (12,028 sq mi) and a total volume of 2,236 km3 (536 cu mi). Its maximum depth is 446 m (1,463 ft) and its average depth 71.7 m (235 ft). The total shoreline is 2,719 km (1,690 mi) and the total catchment area of the lake is 114,717 km2 (44,292 sq mi). The lake empties through the Great Bear River (Sahtúdé) into the Mackenzie River. This lake is surrounded by boreal forest, although the Arctic tundra border lies within 100 mi (160 km) north.
[edit] Prehistoric geology
Great Bear Lake lies between two major physiographic regions: the Kazan Uplands portion of the Canadian Shield and the Interior Plains. Originally it was part of the pre-glacial valleys that were reshaped by erosional effects of ice during the Pleistocene. Since then, the lake has undergone various changes resulting from post-glacial rebound following the melting of the ice. Precambrian rocks of the Canadian Shield form the eastern margin of the McTavish Arm. These rocks of the Precambrian are made up of sedimentary and metamorphic deposits supplemented by igneous intrusions forming dikes and sills.
[edit] Human usage
The only community on the lake is Deline at the southwest end, near the Great Bear River, and it is accessed by Déline Airport or, in the summer, Déline Water Aerodrome. As of the 2006 Census the population was 525.[4]
The former Hudson's Bay Company post, Fort Confidence is located on the Dease River which feeds into Dease Arm at the northeast corner.
The mining area known as Port Radium, site of the Eldorado Mine where pitchblende was discovered, is located on the eastern shore.
Fishing is an important income source and there are five fishing lodges located around the lake.[2] One of which, Plummers Great Bear Lake Lodge which is located on the Dease Arm just north of the Arctic Circle, operate both Great Bear Lake Airport and Great Bear Lake Water Aerodrome. In 1995, a 32.8 kg (72.3 lb) lake trout, the largest ever caught with a rod and reel, was taken on the lake.[5]
[edit] History
In 1930, Gilbert LaBine discovered uranium deposits in the Great Bear Lake region. The Sahtu Dene people took their name from the lake.[3]
[edit] Ice road
Great Bear Lake has one ice road, Deline ice road which links to the community of Tulita. It is used for few weeks out of the year to deliver supplies to the remote community of Deline. The road is about 105 km (65 mi) and follows the Great Bear River. The speed on the ice road is 70 km/h (43 mph) just like the Tuktoyaktuk ice road because there are no portages or stretches of land within the lake. The ice road is used mostly by semi-trailer trucks and the road usually can handle 64,500 kg (142,000 lb). The road usually opens around the middle of January and is subject to closure in late March or early April due to warm weather.[6][7]
From 1960 until 1985 an ice road corridor from Great Slave Lake up the Marian River, and then down the Camsell River system, serviced silver mines at Great Bear Lake. This road was constructed by ice road pioneer John Denison.
[edit] Climate
Great Bear Lake is covered with ice from late November to July.[2] Between 1950 and 1974, this climatic data set was collected at Port Radium:
| Climate data for Port Radium (temperature & precipitation), Norman Wells (sunshine) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Daily mean °C (°F) | −27 (−16.6) |
−27 (−16.6) |
−19.1 (−2.4) |
−10.7 (12.7) |
1.2 (34.2) |
9.0 (48.2) |
12.0 (53.6) |
10.6 (51.1) |
5.3 (41.5) |
−3.2 (26.2) |
−14.8 (5.4) |
−23 (−9.4) |
−7.2 (19.0) |
| Precipitation mm (inches) | 11 (0.43) |
8 (0.31) |
14 (0.55) |
6 (0.24) |
14 (0.55) |
14 (0.55) |
35 (1.38) |
43 (1.69) |
25 (0.98) |
27 (1.06) |
25 (0.98) |
14 (0.55) |
236 (9.29) |
| Sunshine hours | 26.9 | 75.6 | 167.6 | 230.0 | 292.6 | n/a | n/a | 238.0 | 126.1 | 53.7 | n/a | 7.3 | n/a |
| Source no. 1: World Lakes Database[2] | |||||||||||||
| Source no. 2: Sunshine data from 1961-1990 Environment Canada [8] | |||||||||||||
[edit] References
- ^ a b c d e f g h i Johnson, L. (1975), "Physical and chemical characteristics of Great Bear Lake", J. Fish. Res. Board Can. 32 (11): 1971–1987, doi:10.1139/f75-234 quoted at Great Bear Lake (World Lakes Database)
- ^ a b c d e f g h i j Hebert, Paul (2007), "Great Bear Lake, Northwest Territories", Encyclopedia of Earth, Washington, DC: Environmental Information Coalition, National Council for Science and the Environment, http://www.eoearth.org/article/Great_Bear_Lake,_Northwest_Territories, retrieved 2007-12-07
- ^ a b Johnson, L. The Great Bear Lake: Its Place in History. Calgary, Alberta: Arctic Institute of North America (AINA) database at the University of Calgary. pp. 236-237. Retrieved on: 2012-01-30.
- ^ 2006 Census
- ^ Lake Trout (Salvelinus namaycush)
- ^ NWT Road Reports
- ^ Open and Close Dates for the NWT's Community Access Roads
- ^ Environment Canada Canadian Climate Normals 1961–1990 - Norman Wells. Retrieved 30 January 2012.
[edit] External links
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Wikimedia Commons has media related to: Great Bear Lake |
- Great Bear Lake Watershed
- Prehistory of Great Bear Lake
- 1867 account of the lake by William Carpenter Bompas
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