Great Bear Lake

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Great Bear Lake
Deline4.jpg
On the shores of Great Bear Lake
Great Bear Lake (de).png
lake map
Location Northwest Territories
Coordinates 66°N 121°W / 66°N 121°W / 66; -121Coordinates: 66°N 121°W / 66°N 121°W / 66; -121
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)
Frozen November - July[2]
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[pronunciation?], 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 eighth 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]

Contents

Geography[edit]

Bathymetric map of Great Bear Lake.
Smoke from Alaskan Fires in Northwestern Canada blow over Great Bear Lake.

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).[4]

Prehistoric geology[edit]

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 Glacial Lake McConnell in 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.

Human usage[edit]

The settlement of Deline is located on the lake, near the headwaters of the Bear River.[5]

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] In 1995, a 32.8 kg (72.3 lb) lake trout was caught on the lake, which is the largest ever caught by angling.[6]

History[edit]

In 1930, Gilbert LaBine discovered uranium deposits in the Great Bear Lake region. The Sahtu Dene people took their name from the lake.[3]

Ice road[edit]

There is an ice crossing to Deline.[7][8]

Climate[edit]

Great Bear Lake. Note the smoke plumes from wildfires

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) −27.0
(−16.6)
−27.0
(−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)
−23.0
(−9.4)
−7.2
(19)
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)
Mean monthly 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 #1: World Lakes Database[2]
Source #2: Sunshine data from 1961-1990 Environment Canada [9]
Mackenzie River drainage basin showing Great Bear Lake's position in the Western Canadian Arctic

References[edit]

  1. ^ 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)
  2. ^ a b c d e f g h i j k Hebert, Paul (2007), "Great Bear Lake, Northwest Territories", Encyclopedia of Earth, Washington, DC: Environmental Information Coalition, National Council for Science and the Environment, retrieved 2007-12-07 
  3. ^ 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.
  4. ^ "Great Bear Lake". World Lakes Database. International Lake Environment Committee. Retrieved 2 February 2013. 
  5. ^ "Deline - "Where the Water Flows"". Spectacular Northwest Territories. Northwest Territories. Retrieved 2 February 2013. 
  6. ^ "Lake Trout (Salvelinus namaycush)". Fisheries & Aquaculture. Province of Nova Scotia. Retrieved 2 February 2013. 
  7. ^ "Impassable ice roads delay holiday travel". CBC News: North. CBC. 23 December 2009. Retrieved 2 February 2013. 
  8. ^ "Open and Close Dates for the NWT's Community Access Roads". Transportation. Government of the Northwest Territories. Retrieved 2 February 2013. 
  9. ^ Environment Canada Canadian Climate Normals 1961–1990 - Norman Wells. Retrieved 30 January 2012.

External links[edit]