Great Bear Lake
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Great Bear Lake | |
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Location | Northwest Territories |
Coordinates | |
Primary outflows | Great Bear River |
Catchment area | 114,717 km² (44,293 mi²)[1][2] |
Basin countries | Canada |
Surface area | 31,153 km² (12,028 mi²)[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 (of lake water) | 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 in area[1] |
Settlements | Deline, Echo Bay |
References | [2][1] |
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 third largest in North America, and the seventh largest in the world.[3] The lake 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 lake has a surface area of 31,153 km² (12,028 mi²) and a total volume of 2,236 km³ (536 mi³). 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 (44,293 mi²).
The lake empties through the Great Bear River (Sahtúdé) into the Mackenzie River. The only community on the lake is Deline, Northwest Territories at the southwest end.
In 1930 Gilbert LaBine discovered uranium in the Great Bear Lake region.
The Sahtú Dene people took their name from the lake.
Contents[hide] |
[edit] Prehistory
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 preglacial valleys that were reshaped by erosional effects of ice during the Pleistocene. Since then, the lake has undergone various changes resulting from 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] Climate
Great Bear Lake is covered with ice from late November to July.[2] Between 1950 and 1974, this climatic data was collected at Port Radium:
Month | Temperature (°C) |
Precipitation (mm) |
Bright sunshine (hours) |
---|---|---|---|
Jan | –27.0 | 11 | 0.19 |
Feb | –27.0 | 8 | 1.82 |
Mar | –19.1 | 14 | 7.57 |
Apr | –10.7 | 6 | 16.03 |
May | +1.2 | 14 | 21.76 |
Jun | +9.0 | 14 | 23.16 |
Jul | +12.0 | 35 | 18.54 |
Aug | +10.6 | 43 | 11.97 |
Sep | +5.3 | 25 | 6.20 |
Oct | –3.2 | 27 | 2.85 |
Nov | –14.8 | 25 | 0.39 |
Dec | –23.0 | 14 | 0.00 |
Average | –7.2 | 10 | |
Total | 236 |
[edit] See also
[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: 1971-1987 quoted at Great Bear Lake (World Lakes Database)
- ^ a b c d e f g h Hebert, Paul (2007), “Great Bear Lake, Northwest Territories”, Encyclopedia of Earth, Environmental Information Coalition, National Council for Science and the Environment, <http://www.eoearth.org/article/Great_Bear_Lake,_Northwest_Territories>
- ^ Great Bear Lake. The Canadian Enyclopedia.