Lake Ojibway

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Lake Ojibway
Glacial Lake Agassiz and Glacial Lake Ojibway, 7,900 BPE.png
Glacial Lake Agassiz and Lake Ojibway (7,900 YBP)
Canada Ontario relief location map.jpg
Red pog.svg
Lake Ojibway
Location Ontario & Quebec
Coordinates 48°N80°W / 48°N 80°W / 48; -80 Coordinates: 48°N80°W / 48°N 80°W / 48; -80
Lake type former lake
Etymology Chippewa Nation
Primary inflows Laurentide Ice Sheet
Primary outflows Ottawa River valley [1]
Basin  countriesCanada
First flooded9,160 years before present
Max. length1,314 mi (2,115 km)
Max. width365 mi (587 km) 212 mi (341 km)
Residence time 1900 years in existence
Surface elevation820 ft (250 m) [1]
ReferencesColeman, Arthur Philemon (1909). "Lake Ojibway; Last of the Great Glacial Lakes". Ontario Bureau of Mines. Report 18 (4): 284–293. Retrieved 30 October 2015.

Lake Ojibway was a prehistoric lake in what is now northern Ontario and Quebec in Canada. Ojibway was the last of the great proglacial lakes of the last ice age. [2] Comparable in size to Lake Agassiz (to which it was likely linked), and north of the Great Lakes, it was at its greatest extent c. 8,500 years BP. The former lakebed forms the modern Clay Belt, an area of fertile land. [3]

Contents

Lake Ojibway was relatively short-lived. The lake drained in what must have been a catastrophic and dramatic manner around 8,200 years BP. One hypothesis is that a weakening ice dam separating it from Hudson Bay broke, as the lake was roughly 250 m (820 ft) above sea level. A comparable mechanism produced the Missoula floods that created the channeled scablands of the Columbia River basin. [3]

A recent analysis states it has not been conclusively determined whether the lake drained by a breach of the ice dam, by water spilling over the glacier, or by a flood under the glacier. It is also not conclusively known whether there were one or more pulses, and the route the water took to reach Hudson's Bay has not been determined. [3] [4]

The draining of Lake Ojibway is a possible cause of the 8.2-kiloyear event, a major global cooling that occurred 8,200 years BP.

See also

Related Research Articles

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Lake Agassiz was a large glacial lake in central North America. Fed by glacial meltwater at the end of the last glacial period, its area was larger than all of the modern Great Lakes combined, although its mean depth was not as great as that of many major lakes today.

Missoula floods Heavy floods of the last ice age

The Missoula floods were cataclysmic glacial lake outburst floods that swept periodically across eastern Washington and down the Columbia River Gorge at the end of the last ice age. These floods were the result of periodic sudden ruptures of the ice dam on the Clark Fork River that created Glacial Lake Missoula. After each ice dam rupture, the waters of the lake would rush down the Clark Fork and the Columbia River, flooding much of eastern Washington and the Willamette Valley in western Oregon. After the lake drained, the ice would reform, creating Glacial Lake Missoula again.

Lake Missoula Prehistoric proglacial lake in Western Montana

Lake Missoula was a prehistoric proglacial lake in western Montana that existed periodically at the end of the last ice age between 15,000 and 13,000 years ago. The lake measured about 7,770 square kilometres (3,000 sq mi) and contained about 2,100 cubic kilometres (500 cu mi) of water, half the volume of Lake Michigan.

Last Glacial Period Period of major glaciations of the northern hemisphere (115,000–12,000 years ago)

The Last Glacial Period (LGP) occurred from the end of the Eemian to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago. The LGP is part of a larger sequence of glacial and interglacial periods known as the Quaternary glaciation which started around 2,588,000 years ago and is ongoing. The definition of the Quaternary as beginning 2.58 million years ago (Mya) is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Mya, in the mid-Cenozoic. The term Late Cenozoic Ice Age is used to include this early phase.

Glacial Lake Wisconsin Prehistoric lake in Wisconsin, United States

Glacial Lake Wisconsin was a prehistoric proglacial lake that existed from approximately 18,000 to 14,000 years ago, at the end of the last ice age, in the central part of present-day Wisconsin in the United States.

Proglacial lake Lake formed either by the damming action of a moraine during the retreat of a melting glacier, a glacial ice dam, or by meltwater trapped against an ice sheet

In geology, a proglacial lake is a lake formed either by the damming action of a moraine during the retreat of a melting glacier, a glacial ice dam, or by meltwater trapped against an ice sheet due to isostatic depression of the crust around the ice. At the end of the last ice age about 10,000 years ago, large proglacial lakes were a widespread feature in the northern hemisphere.

Jökulhlaup Type of glacial outburst flood

A jökulhlaup is a type of glacial outburst flood. It is an Icelandic term that has been adopted in glaciological terminology in many languages. It originally referred to the well-known subglacial outburst floods from Vatnajökull, Iceland, which are triggered by geothermal heating and occasionally by a volcanic subglacial eruption, but it is now used to describe any large and abrupt release of water from a subglacial or proglacial lake/reservoir.

In geomorphology, an outburst flood—a type of megaflood—is a high-magnitude, low-frequency catastrophic flood involving the sudden release of a large quantity of water. During the last deglaciation, numerous glacial lake outburst floods were caused by the collapse of either ice sheets or glaciers that formed the dams of proglacial lakes. Examples of older outburst floods are known from the geological past of the Earth and inferred from geomorphological evidence on Mars. Landslides, lahars, and volcanic dams can also block rivers and create lakes, which trigger such floods when the rock or earthen barrier collapses or is eroded. Lakes also form behind glacial moraines, which can collapse and create outburst floods.

Channeled Scablands Landscape in eastern Washington state scoured by cataclysmic floods during the Pleistocene epoch

The Channeled Scablands at one time were a relatively barren and soil-free region of interconnected relict and dry flood channels, coulees and cataracts eroded into Palouse loess and the typically flat-lying basalt flows that remain after cataclysmic floods within the southeastern part of the U.S. state of Washington. The Channeled Scablands were scoured by more than 40 cataclysmic floods during the Last Glacial Maximum and innumerable older cataclysmic floods over the last two million years. These floods were periodically unleashed whenever a large glacial lake broke through its ice dam and swept across eastern Washington and down the Columbia River Plateau during the Pleistocene epoch. The last of the cataclysmic floods occurred between 18,200 and 14,000 years ago.

Laurentide Ice Sheet Continental glacier in North America during the last ice age

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Diluvium Deposits created as a result of catastrophic outbursts of Pleistocene giant glacier-dammed lakes

Historically, diluvium was a term in geology for superficial deposits formed by flood-like operations of water, and so contrasted with alluvium or alluvial deposits formed by slow and steady aqueous agencies. The term was formerly given to the boulder clay deposits, which some early geologists supposed had been caused by the Noachian deluge, a concept known as flood geology or diluvialism.

The Tyrrell Sea, named after Canadian geologist Joseph Tyrrell, is another name for prehistoric Hudson Bay, namely as it existed during the retreat of the Laurentide Ice Sheet.

Glacial lake outburst flood Type of outburst flood that occurs when the dam containing a glacial lake fails

A glacial lake outburst flood (GLOF) is a type of outburst flood caused by the failure of a dam containing a glacial lake. An event similar to a GLOF, where a body of water contained by a glacier melts or overflows the glacier, is called a jökulhlaup. The dam can consist of glacier ice or a terminal moraine. Failure can happen due to erosion, a buildup of water pressure, an avalanche of rock or heavy snow, an earthquake or cryoseism, volcanic eruptions under the ice, or massive displacement of water in a glacial lake when a large portion of an adjacent glacier collapses into it.

Moses Coulee Canyon in the Waterville plateau region of Douglas County, Washington

Moses Coulee is a canyon in the Waterville plateau region of Douglas County, Washington. Moses Coulee is the second-largest and westernmost canyon of the Channeled Scablands, located about 30 kilometres (19 mi) to the west of the larger Grand Coulee. This water channel is now dry, but during glacial periods, large outburst floods with discharges greater than 600,000 m3/s (21,000,000 cu ft/s) carved the channel. While it's clear that megafloods from Glacial Lake Missoula passed through and contributed to the erosion of Moses Coulee, the origins of the coulee are less clear. Some researchers propose that floods from glacial Lake Missoula formed Moses Coulee, while others suggest that subglacial floods from the Okanogan Lobe incised the canyon. The mouth of Moses Coulee discharges into the Columbia River.

Glacial River Warren, also known as River Warren, was a prehistoric river that drained Lake Agassiz in central North America between about 13,500 and 10,650 BP calibrated years ago. A part of the uppermost portion of the river channel was designated a National Natural Landmark in 1966.

Floods in the United States before 1901 is a list of flood events that were of significant impact to the country, before 1901. Floods are generally caused by excessive rainfall, excessive snowmelt, and dam failure.

Lake Condon

Lake Condon was a temporary lake in the Pacific Northwest region of North America, formed periodically by the Missoula Floods from 15,000 to 13,000 BC.

Altai flood Prehistoric event in Central Asia

The Altai flood refers to the cataclysmic flood(s) that, according to some geomorphologists, swept along the Katun River in the Altai Republic at the end of the last ice age. These glacial lake outburst floods were the result of periodic sudden ruptures of ice dams like those triggering the Missoula floods.

The phenomenon of paleoflooding is apparent in the geologic record over various spatial and temporal scales. It often occurred on a large scale, and was the result of either glacial ice melt causing large outbursts of freshwater, or high sea levels breaching bodies of freshwater. If a freshwater outflow event was large enough that the water reached the ocean system, it caused changes in salinity that potentially affected ocean circulation and global climate. Freshwater flows could also accumulate to form continental glacial lakes, and this is another indicator of large-scale flooding. In contrast, periods of high global sea level could cause marine water to breach natural dams and flow into bodies of freshwater. Changes in salinity of freshwater and marine bodies can be detected from the analysis of organisms that inhabited those bodies at a given time, as certain organisms are more suited to live in either fresh or saline conditions.

References

  1. 1 2 Examining the progression and termination of Lake Agassiz; Michael J. Michalek; April 23, 2013
  2. Coleman, Arthur Philemon (1909). "Lake Ojibway; Last of the Great Glacial Lakes" (PDF). Ontario Bureau of Mines . Report 18 (4): 284–293. Retrieved 30 October 2015.
  3. 1 2 3 Lajeunesse, P.; St-Onge, G. (2007). "Reconstruction of the Last Outburst Flood of Glacial Lake Agassiz-Ojibway in Hudson Bay and Hudson Strait". American Geophysical Union, Fall Meeting 2007. Bibcode:2007AGUFM.C51A0075L.
  4. Pielou, E.C. (1991). After the Ice Age. Chicago: University of Chicago Press. ISBN   9780226668123.