Manicouagan Reservoir (also Lake Manicouagan ; ) is an annular lake in central

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

, Canada, covering an area of . The lake island in its centre is known as René-Levasseur Island, and its highest point is Mount Babel. The structure was created 214 (±1) million years ago, in the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch a ...

, by the impact of a meteorite in diameter. The lake and island are clearly seen from space and are sometimes called the "eye of Quebec". The lake has a volume of .

Geography

Manicouagan Reservoir in winter by Sentinel-2

The reservoir is located in Manicouagan Regional County Municipality in the

Côte-Nord Côte-Nord (Region 09) (, ; ) is an List of regions of Quebec, administrative region of Quebec, on the Quebec-Labrador peninsula, Quebec-Labrador Peninsula, Canada. The region runs along the St. Lawrence River and then the Gulf of St. Lawrence, ...

region of Quebec, Canada, about north of the city of Baie-Comeau, although its northernmost part is located in Caniapiscau Regional County Municipality. Quebec Route 389 passes the eastern shore of the lake. The crater is a multiple-ring structure about across, with the reservoir at its diameter inner ring being its most prominent feature. It surrounds an inner island plateau called René-Levasseur Island and Mount Babel is the highest peak of the island, at above sea level and above the reservoir level. The Louis-Babel Ecological Reserve makes up the central part of the island. The large bay on the eastern shore of the island is named Memory Bay.

Impact structure

Manicouagan Reservoir lies within the remnant of an ancient, deeply eroded impact crater ( Impact structure). The crater was formed following the impact of an

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

with a diameter of , which excavated a crater originally about wide, although erosion and deposition of sediments have since reduced the visible diameter to about . It is the Earth's sixth-largest confirmed impact structure according to rim-to-rim diameter. Mount Babel is interpreted as the central peak of the crater, formed by post-impact uplift. 1992 radiometric dating has estimated that impact melt within the impact structure has an age of 214 ± 1 million years. A later estimate found an age of 215.4 ± 0.16 Ma. As this is more than 12 million years before the end of the Triassic, the impact that produced the crater cannot have been the cause of the Triassic–Jurassic extinction event.

Multiple impact event claims

It was suggested that the Manicouagan crater may have been part of a multiple

impact event An impact event is a collision between astronomical objects causing measurable effects. Impact events have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal effe ...

, similar to the well-observed string of impacts of Comet Shoemaker–Levy 9 on

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in 1994. The theory suggests this event also formed the Rochechouart impact structure in France, the Saint Martin crater in

Manitoba Manitoba is a Provinces and territories of Canada, province of Canada at the Centre of Canada, longitudinal centre of the country. It is Canada's Population of Canada by province and territory, fifth-most populous province, with a population ...

, the Obolon' crater in

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, and the Red Wing crater in North Dakota; however, more recent work has found that the craters formed many millions of years apart, with the Saint Martin crater dating to 227.8 ± 1.1 Ma, while the Rochechouart structure formed 206.92 ± 0.20/0.32 Ma.

Hydroelectric project

The Manicouagan Reservoir as it presently exists was created in the 1960s, by flooding the earlier Lake Mushalagan (Mouchalagan) to the west of the central plateau and then-smaller Manicouagan to the east, by construction of the Daniel-Johnson dam. The works were part of the enormous Manicouagan or Manic series of

hydroelectric Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

projects undertaken by

Hydro-Québec Hydro-Québec () is a Canadian Crown corporations of Canada#Quebec, Crown corporation public utility headquartered in Montreal, Quebec. It manages the electricity generation, generation, electric power transmission, transmission and electricity ...

, the provincial electrical utility. The complex of dams is also called the Manic-Outardes Project because the rivers involved are the Manicouagan and the Outardes. The reservoir acts as a giant headpond for the Manicouagan River, feeding the Jean-Lesage generating station (Manic-2), René-Lévesque generating station (Manic-3), and Daniel-Johnson Dam ( Manic-5) generating stations downstream. In the peak period of the winter cold, the lake surface is usually lower, since the turbines run all the time at peak load to meet the huge electrical heating needs of the province. The surface of the lake also experiences low levels in the extreme periods of heat in

New England New England is a region consisting of six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the ...

during the summer, since in that period Hydro-Québec sells electrical energy to the joint New England grid and individual utilities in the United States.

References

External links