Lake Agassiz

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Lake Agassiz

Lake Agassiz was an immense glacial lake

Glacial lake

A glacial lake is a lake with origins in a melted glacier.Glacial lakes can be green as a result of pulverized minerals that support a large population of algae....
located in the center of North America

North America

North America is the northern continent of the Americas, situated in the Earth's northern hemisphere and almost totally in the western hemisphere....
. Fed by glacial runoff at the end of the last glacial period, its area was larger than all of the present-day Great Lakes

Great Lakes

The St. Lawrence River Great Lakes are a chain of fresh water lakes located in eastern North America, on the Canada ? United States border. Consisting of Lakes Lake Superior, Lake Michigan, Lake Huron, Lake Erie, and Lake Ontario, they form the largest group of freshwater lakes on Earth....
combined.

t postulated in 1823 by William Keating

William Keating

William Hypolitus Keating was an United States geologist. His father, Baron John Keating, of Ireland ancestry, had been an officer in the France army in the West Indies and had settled in Wilmington, Delaware....
, it was named after Louis Agassiz

Louis Agassiz

Jean Louis Rodolphe Agassiz was a paleontologist, glaciologist, and geologist, and was a prominent innovator in the study of the earth's natural history....
in 1879 after he was the first to realize it was formed by glacial action.

ogists have come to a consensus on the likely geological progression of Lake Agassiz.

Forming around 13,000 calendar years before present (almost 12,000 ¹⁴C years before present), the lake came to cover much of Manitoba

Manitoba

Manitoba is a prairie provinces in Canada, which has an area of 647,797 square kilometres and a population of 1,207,959 , with more than half located within the Winnipeg Capital Region ....
, western Ontario

Ontario

Ontario is a Provinces and territories of Canada located in the Central Canada part of Canada, the largest by population and second largest, after Quebec, in total area....
, northern Minnesota

Minnesota

Minnesota is a U.S. state in the Midwestern United States of the United States. The twelfth largest state by area in the U.S., it is the twenty-first most populous, with just over five million residents....
, eastern North Dakota

North Dakota

North Dakota is a U.S. state located in the Midwestern United States and Western United States regions of the United States of America. North Dakota is the 19th largest state by area in the US; it is the 48th most populous, with just over 640,000 residents as of 2006....
, and Saskatchewan

Saskatchewan

Saskatchewan is a prairie provinces in Canada, which has an area of 588,276.09 square kilometres and a population of 1,015,895 , mostly living in the southern half of the province....
.

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Lake Agassiz was an immense glacial lake

Glacial lake

North America

Great Lakes

Conception

First postulated in 1823 by William Keating

William Keating

Louis Agassiz

Geological progression

Geologists have come to a consensus on the likely geological progression of Lake Agassiz.

Forming around 13,000 calendar years before present (almost 12,000 ¹⁴C years before present), the lake came to cover much of Manitoba

Manitoba

Ontario

Ontario is a Provinces and territories of Canada located in the Central Canada part of Canada, the largest by population and second largest, after Quebec, in total area....
, northern Minnesota

Minnesota

North Dakota

Saskatchewan

Saskatchewan is a prairie provinces in Canada, which has an area of 588,276.09 square kilometres and a population of 1,015,895 , mostly living in the southern half of the province....
. At its greatest extent, it may have covered as much as 440,000 square kilometers, larger than any currently existing lake in the world (including the Caspian Sea

Caspian Sea

The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the List of lakes by area or a full-fledged sea. It has a surface area of 371,000 square kilometers and a volume of 78,200 cubic kilometers ....
). This is roughly the size of Iraq

Iraq

Iraq , officially the Republic of Iraq , is a country in Western Asia spanning most of the northwestern end of the Zagros Mountains, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....
, the 58th largest country

List of countries and outlying territories by total area

This is a list of the Sovereignty of the world sorted by total area.For statistical purposes, dependent territories are listed separately from their sovereign state and are set off in italics....
in the world, and larger than California

California

California is a U.S. state on the West Coast of the United States of the United States, along the Pacific Ocean. It is bordered by Oregon to the north, Nevada to the east, Arizona to the southeast, and to the south the Mexico state of Baja California....
, the third largest U.S. state

List of U.S. states by area

This is a complete list of the U.S. state and its major Territories of the United States ordered by total area, land area, and water area....
, but smaller than the Yukon

Yukon

Yukon is the westernmost and smallest of Canada three Territories of Canada. It was named after the Yukon River, Yukon meaning "Great River" in Gwich?in language....
, the ninth largest Canadian territory or province

List of Canadian provinces and territories by area

This is a list of Canadian provinces and territories by area. Canada has Provinces and territories of Canada. In total area, Canada is the List of countries and outlying territories by total area in the world; in land area, however, Geography of Canada....
.

The lake drained at various times south through the Traverse Gap

Traverse Gap

The Traverse Gap is an ancient river channel occupied by Lake Traverse and Big Stone Lake and the valley connecting them at Browns Valley, Minnesota....
into Glacial River Warren

Glacial River Warren

Glacial River Warren or River Warren was a prehistoric river that drained Lake Agassiz in central North America between 11,700 and 9,400 years ago....
(parent to the Minnesota River

Minnesota River

The Minnesota River is a tributary of the Mississippi River, approximately 332 miles long, in the U.S. state of Minnesota. It drains a drainage basin of nearly 17,000 square miles , 14,751 square miles in Minnesota and about 2,000 sq mi in South Dakota and Iowa....
, a tributary of the Mississippi River

Mississippi River

The Mississippi River is the longest river in the United States, with a length of from its source in Lake Itasca in Minnesota to its mouth in the Gulf of Mexico....
), into the Great Lakes

Great Lakes

Alaska

Alaska is the largest U.S. state of the United States by area; it is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait....
. Climatologists believe that a major outbreak of Lake Agassiz in about 11000 BC drained through the Great Lakes and Saint Lawrence River

Saint Lawrence River

Saint Lawrence River is a large river flowing approximately from southwest to northeast in the middle latitudes of North America, connecting the Great Lakes with the Atlantic Ocean....
into the Atlantic Ocean

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions; with a total area of about 106.4 million square kilometres . It covers approximately one-fifth of the Earth's surface....
. This may be the cause of the Younger Dryas

Younger Dryas

The Younger Dryas stadial, named after the alpine/tundra wildflower Dryas octopetala, and also referred to as the Big Freeze, was a brief cold climate period following the B?lling/Aller?d Oscillation interstadial at the end of the Pleistocene between approximately 12,800 to 11,500 years Before Present, and preceding the Boreal of t...
stadial

Stadial

A stadial is a period of colder temperatures during an interglacial, of insufficient duration or intensity to be considered a glaciation, or glacial period....
. 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 civilization.

Much of the final drainage of Lake Agassiz may have occurred in a very short time—perhaps as little as one year. A recent study by Turney and Brown links this rapid drainage and subsequent global sea level rise of about one meter to the expansion of agriculture in Europe; he suggests that this may also account for various flood myths of prehistoric cultures, including the Biblical flood.

The last major shift in drainage occurred about 8,400 calendar years before present (about 7,700 ¹⁴C years before present), when the lake took up its current watershed, draining into Hudson Bay

Hudson Bay

Hudson Bay is a large , relatively shallow body of water in northeastern Canada. It is approximately 850 miles long and 650 miles wide. It drains a very large area that includes parts of Ontario, Quebec, Saskatchewan, Alberta, most of Manitoba, parts of North Dakota, South Dakota, Minnesota, and Montana, and the southeastern area of Nunavut...
. The lake drained nearly completely over the next 1,000 years or so, leaving behind Lake Winnipeg

Lake Winnipeg

Lake Winnipeg is a very large lake in central North America, in the Provinces and territories of Canada of Manitoba, Canada, about north of the city of Winnipeg, Manitoba....
, Lake Winnipegosis

Lake Winnipegosis

Lake Winnipegosis is a large lake in central North America, in Manitoba, Canada, some 300 km northwest of Winnipeg, Manitoba. It is Canada's eleventh-largest lake....
, Lake Manitoba

Lake Manitoba

Lake Manitoba is Canada's thirteenth largest lake and the world's 33rd largest freshwater lake. It is in central North America, in the Canada province of Manitoba, which the lake is named after....
, and Lake of the Woods

Lake of the Woods

Lake of the Woods is a lake occupying parts of the Canadian provinces of Ontario and Manitoba and the U.S. state of Minnesota. It separates a small land area of Minnesota from the rest of the United States....
, among others. The outlines and volumes of these lakes are still slowly changing due to differential isostatic rebound.

Other geological and geomorphological evidence for Lake Agassiz can also be seen today. Raised beach

Raised beach

Sorry, no overview for this topic
es, many kilometers from any water, mark the former boundaries of the lake at various times. Several modern river valleys, including the Red River

Red River of the North

The Red River is a North American river. Formed by the confluence of the Bois de Sioux River and Otter Tail River rivers in the United States, it flows northward through the Red River Valley and forms the border between the U.S....
, the Assiniboine River

Assiniboine River

The Assiniboine River is a long river that runs through the prairies of Western Canada in Saskatchewan and Manitoba.It is a typical meandering river with a single main channel embanked within a flat, shallow valley at some places, and a steep valley at other places....
and the Minnesota River

Minnesota River

Red River Valley

The Red River Valley is a region in central North America that is drained by the Red River of the North. It is significant in the geography of North Dakota, Minnesota, and Manitoba for its relatively fertile lands and the population centers of Fargo, North Dakota, Grand Forks, North Dakota, and Winnipeg, Manitoba....
agricultural region are Lake Agassiz silt

Silt

Silt is soil or Rock derived granular material of a Particle size between sand and clay. Silt may occur as a soil or as suspended sediment in a surface water body....
.

Lake Agassiz

Conception

Geological progression

See also

Sources

Books, journals and monographs

Websites

External links