Great Lakes (redirected from Great Lake)

Great Lakes, group of five freshwater lakes, central North America, creating a natural border between the United States and Canada and forming the largest body of freshwater in the world, with a combined surface area of c.95,000 sq mi (246,050 sq km). From west to east they are Lake Superior, Lake Michigan, Lake Huron, Lake Erie, and Lake Ontario, out of which flows the Saint Lawrence River. The distance from Duluth, Minn., at the western end of Lake Superior, to the outlet of Lake Ontario is 1,160 mi (1,867 km). The international boundary passes approximately through the center of all the lakes except Lake Michigan, which lies entirely within the United States.

The Great Lakes were formed approximately at the end of the Pleistocene period, when the glacier-carved lake basins were filled with meltwater from the retreating ice sheet. The lakes are connected to each other by straits, short rivers, and canals. The height above sea level of the lake surfaces varies from Lake Superior's 602 ft (183 m) to Lake Ontario's 246 ft (75 m); the greatest sudden drop occurs at Niagara Falls (167 ft/51 m) between lakes Erie and Ontario; the water levels fluctuate over the months and years due to climatic changes. All the lake bottoms, except that of Lake Erie, extend below sea level.

French traders were the first Europeans to see any of the Great Lakes; Étienne Brulé visited Lake Huron c.1612. In 1614, Brulé and French explorer Samuel de Champlain explored Lake Huron and Lake Ontario. In 1679, French explorer Robert LaSalle sailed from Lake Erie to Lake Michigan. The Great Lakes region, rich in furs, was contested for many years by the French, English, and Americans. The close of the War of 1812 finally ended the struggle for possession of the Great Lakes, and settlement of the region rapidly followed. The opening of the Erie Canal in 1825 accelerated the development of commerce on the Great Lakes.

The opening of the St. Lawrence Seaway in 1959 made the Great Lakes a truly international water body. The Illinois Waterway connects the lakes with the Mississippi River and the Gulf of Mexico; the New York State Canal System (including the Erie Canal) joins the Great Lakes with the Hudson River and the Atlantic Ocean. Shipping on the lakes carries large quantities of iron ore and grain, coal, and petroleum, and manufactured articles from April until December, until ice closes most of the ports and winter storms hinder navigation. The large industrial lakefront cities include Toronto, Hamilton, Buffalo, Cleveland, Detroit, Gary, Milwaukee, and Chicago. Large concentrations of population and industry along the lakes' shores led to pollution, especially of Lake Erie, but the condition of the lakes has improved since the 1960s. The Great Lakes region, with its national parks and lakeshores, state parks, and many natural and scenic features, has become an important year-round recreation area.

Bibliography

See J. Rousmaniere, ed., The Enduring Great Lakes (1979); C. E. Feltner and J. B. Feltner, Great Lakes Maritime History (1982); S. L. Flader, ed., The Great Lakes Forest (1983).

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Great Lakes

Chain of lakes, east-central North America. Comprising Lakes Superior, Michigan, Huron, Erie, and Ontario, it forms a natural boundary between the U.S. and Canada. The Great Lakes cover an area of about 94,850 sq mi (245,660 sq km) and constitute the largest freshwater surface in the world. Connected to form a single waterway that discharges down the St. Lawrence River into the Atlantic Ocean, with the St. Lawrence Seaway they form a shipping lane more than 2,000 mi (3,200 km) long that carries oceangoing traffic as far west as Duluth, Minn. Large quantities of iron ore, coal, grain, and manufactured goods are moved between lake ports and shipped overseas. While commercial fishing was once a major industry on the lakes, pollution and other factors led to its collapse; recovery has been slow and partial. The lakes are used for many recreational activities, including boating and sailing.

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Great Lakes

Group of large lakes located chiefly in the Great Rift Valley, eastern central Africa. It includes the lakes Turkana, Albert, Victoria, Tanganyika, and Malawi.