A map of the extent of Lake Agassiz

Lake Agassiz was an immense lake—bigger than all of the present-day Great Lakes combined—in the center of North America, which was fed by glacial runoff at the end of the last ice age. First postulated in 1823 by William Keating, it was named after Louis Agassiz in 1879 after he was the first to realize it was formed by glacial action. Image File history File links Download high resolution version (938x713, 309 KB)Map of the extent of glacial Lake Agassiz. ... Image File history File links Download high resolution version (938x713, 309 KB)Map of the extent of glacial Lake Agassiz. ... The Great Lakes from space The Great Lakes are a group of five large lakes on or near the United States-Canadian border. ... World map showing location of North America A satellite composite image of North America North America is a continent in the northern hemisphere, bounded on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the south by the Caribbean Sea, and on the west... Variations in CO2, temperature and dust from the Vostok ice core over the last 400 000 years For the animated movie, see Ice Age (movie). ... 1823 was a common year starting on Wednesday (see link for calendar). ... William Hypolitus Keating (August 11, 1799-1844) was an American geologist. ... Jean Louis Rodolphe Agassiz (May 28, 1807-December 14, 1873) was a Swiss-born American zoologist, glaciologist, and geologist, the husband of educator Elizabeth Cabot Cary Agassiz, and one of the first world-class American scientists. ... 1879 was a common year starting on Wednesday (see link for calendar). ...

The lake's modern-day remnants, the largest of which is Lake Winnipeg, dominate the geography of Manitoba. Forming around 11,700 years ago, the lake came to cover much of Manitoba, western Ontario, northern Minnesota, northern North Dakota, and Saskatchewan. At its greatest extent it may have covered as much as 440,000 square kilometers, larger than any lake currently in the world (including the Caspian Sea). Lake Winnipeg (52°N, 92°W) is a large (24 400 km²) lake in central North America, in the province of Manitoba, Canada, at about 55 km north of the city of Winnipeg. ... Motto: Gloriosus et Liber (Glorious and free) Other Canadian provinces and territories Capital Winnipeg Largest city Winnipeg Lieutenant Governor John Harvard Premier Gary Doer (NDP) Area 647,797 km² (8th) Land 553,556 km² Water 64,241 km² (14. ... Motto: Gloriosus et Liber (Glorious and free) Other Canadian provinces and territories Capital Winnipeg Largest city Winnipeg Lieutenant Governor John Harvard Premier Gary Doer (NDP) Area 647,797 km² (8th) Land 553,556 km² Water 64,241 km² (14. ... Motto: Ut Incepit Fidelis Sic Permanet (Loyal it began, loyal it remains) Other Canadian provinces and territories Capital Toronto Largest city Toronto Lieutenant Governor James K. Bartleman Premier Dalton McGuinty (Liberal) Area 1,076,395 km² (4th)  - Land 917,741 km²  - Water 158,654 km² (14. ... State nickname: North Star State Other U.S. States Capital Saint Paul Largest city Minneapolis Governor Tim Pawlenty (R) Official languages None Area 225,365 km² (12th)  - Land 206,375 km²  - Water 18,990 km² (8. ... State nickname: Peace Garden State, Roughrider State, Flickertail State Other U.S. States Capital Bismarck Largest city Fargo Governor John Hoeven (R) Official languages English Area 183 272 km² (19th)  - Land 178 839 km²  - Water 4 432 km² (2. ... Motto: Multis E Gentibus Vires (From many peoples, strength) Other Canadian provinces and territories Capital Regina Largest city Saskatoon Lieutenant Governor Lynda M. Haverstock Premier Lorne Calvert (NDP) Area 651,036 km² (7th) Land 591,670 km² Water 59,366 km² (9. ... Caspian Sea viewed from orbit The Caspian Sea or Mazandaran Sea is a landlocked sea between Asia and Europe (European Russia). ...

The lake drained at various times south into the Minnesota River (part of the Mississippi River system), into the Great Lakes, or west through the Yukon Territory and Alaska. A return of the ice for some time offered a reprieve, and after retreating north of the Canadian border about 9,900 years ago it refilled. These events had significant impact on climate, sea level and possible early human civilizations. Climatologists believe that a major outbreak of Lake Agassiz in about 11000 BC drained through the Great Lakes and Saint Lawrence River into the Atlantic Ocean. The massive outflow of fresh water slowed ocean current circulation, cutting off the Gulf Stream and bringing about a ten-century global cooling known as the Younger Dryas. The Minnesota River is a tributary of the Mississippi River, approximately 332 miles (534 km) long, in the state of Minnesota in the United States. ... Length 6,270 km Elevation of the source 450 m Average discharge Saint Louis¹: 5,500 m³/s Vicksburg²: 16,800 m³/s Baton Rouge³: 12,800 m³/s Area watershed 2,980,000 km² Origin  Lake Itasca Mouth  Gulf of Mexico Basin countries United States (98. ... The Great Lakes from space The Great Lakes are a group of five large lakes on or near the United States-Canadian border. ... Motto: none Other Canadian provinces and territories Capital Whitehorse Largest city Whitehorse Commissioner Jack Cable Premier Dennis Fentie (Yukon Party) Area 482,443 km² (9th)  - Land 474,391 km²  - Water 8,052 km² (1. ... State nickname: The Last Frontier, The Land of the Midnight Sun Other U.S. States Capital Juneau Largest city Anchorage Governor Frank Murkowski (R) Official languages English Area 1,717,854 km² (1st)  - Land 1,481,347 km²  - Water 236,507 km² (13. ... The Saint Lawrence River (French: fleuve Saint-Laurent) is a large west-to-east flowing river in the middle latitudes of North America, connecting the Great Lakes with the Atlantic Ocean. ... For the album by Ocean Colour Scene, see North Atlantic Drift (album) The Gulf Stream is orange and yellow in this representation of water temperatures of the Atlantic. ... The Younger Dryas stadial, named after the alpine / tundra wildflower Dryas octopetala, and also referred to as the Big Freeze [1], was a brief cold climate period following the Bölling/Allerød interstadial at the end of the Pleistocene, and preceding the Preboreal of the early Holocene. ...

The last major shift in drainage occurred about 8,400 years ago, when the lake took up its current watershed, that of Hudson Bay. The lake drained nearly completely over the next 1,000 years or so, leaving behind Lake Winnipeg, Lake Winnipegosis, Lake Manitoba, and Lake of the Woods, among others. These lakes are still shrinking slowly, due to isostatic rebound. Most of the lake drainage may have occurred in a very short time - perhaps as little as one year - and is believed to be responsible for the "8.2 kyr event" visible in ice cores and other climate records. Note that there is a slight incompatibility in the 8.2 vs 8.4 kyr datings. Hudson Bay, Canada. ... Lake Winnipeg (52°N, 92°W) is a large (24 400 km²) lake in central North America, in the province of Manitoba, Canada, at about 55 km north of the city of Winnipeg. ... Lake Winnipegosis (52°30N 100°W) is a large (5370 sq²) lake in central North America, in Manitoba, Canada, some 300 km northwest of Winnipeg. ... Lake Manitoba is a large (4 624 sq. ... Lake of the Woods. ... Post-glacial rebound (sometimes called continental rebound, isostatic rebound or isostatic adjustment) is the rise of land masses that were depressed by the huge weight of ice sheets during the last ice age, through a process known as isostatic depression. ... Image File history File links As for Image:Epica-vostok-grip-40kyr. ...

While mostly gone along with the ice sheet that fed it, Lake Agassiz left marks over a wide geographic area. Apparent beaches, miles from any water, can be found in many locations—these mark the former boundaries of the lake. Several modern river valleys, including the Red River, the Assiniboine River and the afore-mentioned Minnesota River, were originally cut by water entering or leaving the lake. The Red River Valley agricultural region also exists because of the silt that sank to the bottom of the lake. See also the Red River disambiguation page. ... The Assiniboine River is a river 1070 km long that runs through the prairies of western Canada. ... The term Red River has the following uses: Rivers Red River of the North, a river that flows northward between North Dakota and Minnesota into Lake Winnipeg, site of the Red River Settlement; also center of the Red River Basin, a historic region of the United States Red River (Mississippi...

External links

• Lake Agassiz Overview
• Map of glacial Lake Agassiz by Minnesota Dept. of Natural Resources
• Warren Upham (1895) The Glacial Lake Agassiz (monograph). United States Geological Survey, Washington.