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 Superior, Lake, largest freshwater lake in the world, 31,820 sq mi (82,414 sq km), 350 mi (563 km) long and 160 mi (257 km) at its greatest width, bordered on the W by NE Minnesota, on the N and E by Ontario, Canada, and on the S by NW Michigan and NW Wisconsin;
..... Click the link for more information. , Lake Michigan Michigan, Lake, 22,178 sq mi (57,441 sq km), 307 mi (494 km) long and 30 to 120 mi (48–193 km) wide, bordered by Mich., Ind., Ill., and Wis.; third largest of the Great Lakes and the only one entirely within the United States.
..... Click the link for more information. , Lake Huron Huron, Lake , 23,010 sq mi (59,596 sq km), 206 mi (332 km) long and 183 mi (295 km) at its greatest width, between Ont., Canada, and Mich.; second largest of the Great Lakes.
..... Click the link for more information. , Lake Erie Erie, Lake, 9,940 sq mi (25,745 sq km), 241 mi (388 km) long and from 30 to 57 mi (48–92 km) wide, bordered on the N by S Ont., Canada, on the E by W N.Y., on the S by NW Pa. and N Ohio, and on the W by SE Mich. and NW Ohio.; fourth largest of the Great Lakes.
..... Click the link for more information. , and Lake Ontario Ontario, Lake, 7,540 sq mi (19,529 sq km), 193 mi (311 km) long and 53 mi (85 km) at its greatest width, between SE Ont., Canada, and NW N.Y.; smallest and lowest of the Great Lakes.
..... Click the link for more information. , 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 Saint Lawrence Seaway, international waterway, 2,342 mi (3,769 km) long, consisting of a system of canals, dams, and locks in the St. Lawrence River and connecting channels between the Great Lakes; opened 1959.
..... Click the link for more information. 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).

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.

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.

Great Lakes

a group of large lakes in the eastern part of North America, in the St. Lawrence River basin. They consist of Lakes Superior, Huron, Michigan, Erie, and Ontario. Lake Michigan is entirely within the USA, and the border between the USA and Canada runs through the rest of the lakes and the short rivers that connect them. About one-third of the water area belongs to Canada.

Table 1. Great Lakes
	Altitude above sea level (m)	Area (thousand sq km)	Greatest depth (m)
Superior ...............	183	82.4	393
Huron ...............	177	59.6	208
Michigan ...............	177	58.0	281
Erie ...............	174	25.7	64
Ontario ...............	75	19.5	236

The shore line (with islands) is about 18,000 km long. The Great Lakes are the largest accumulation of fresh water on earth. Their area is 245,200 sq km, and the area of their basin (including the lakes themselves) is 768,000 sq km. Their volume of water is 22,725 cubic km. Four lakes have depths greater than 200 m, and only in Lake Erie is the greatest depth 64 m. The largest and deepest of the lakes is Lake Superior, and the smallest is Lake Ontario. The Great Lakes are situated on different levels, but the height difference of the first four (see Table 1) does not exceed 9 m in all (183 m, Lake Superior and 174 m, Lake Erie), and only the lowest lake, Ontario, is situated almost 100 m below Lake Erie. The lakes are united by short, large-volume rivers with many rapids; the Ste. Marie River unites Lake Superior and Lake Huron (112 km long); the St. Clair River (43 km), Lake St. Clair (1,275 sq km in area), and the Detroit River (51 km) unite Lake Huron and Lake Erie; and the Niagara River (54 km), which forms Niagara Falls (c. 50 m high), unites Lake Erie and Lake Ontario. Lakes Huron and Michigan, which are at the same altitude, are joined by the Straits of Mackinac, which are about 3 km wide. Several hundred small rivers fall into the Great Lakes, which drain through the St. Lawrence River and flow from Lake Ontario into the Atlantic Ocean. The average outflow of water at its source is 6,637 cu m per sec.

The basins of Lake Superior and the northern part of Lake Huron were formed from the crystalline rocks of the southern part of the Canadian shield, whereas those of the remaining lakes were formed from a mass of limestones, dolomite, and sandstones of the Paleozoic North American platform. These basins formed as a result of tectonic movement and pre-Ice Age and Ice Age river and glacial erosion. The origin of the Great Lakes water mass is related to the melting of the glacial cover, the recession of which formed in the area a series of large lakes, which changed their outlines many times. The northern part of the shore line is broken, and the islands and shores (to 400 m high) are rocky, precipitous, and very picturesque. This is particularly true of the shores of Lake Superior and the northern parts of Lake Huron. The shores of the southern and southeastern parts of the lakes are primarily low, clayey, and sandy.

Fluctuations of the level of the Great Lakes is artificially regulated for purposes of navigation, power generation, and so on. The amplitude of seasonal fluctuation is 30-60 cm; the highest levels come in the summer and the lowest in winter. Short-term fluctuations in the water level caused by strong winds and seiches reach 3-4 m. The height of the tides is 3-4 cm (Lakes Superior and Michigan). The lakes freeze only in the shore zone (from December to March or April). As a result of frequent fall and winter storms the central parts of the lakes do not remain completely frozen over. The duration of navigability is eight to nine months a year.

In the lakes are found 173 species of fish, mainly of the carp, perch, and salmon families. Whitefish and trout are of economic significance.

In the south and southeast heavily settled industrial regions of the USA and Canada border on the Great Lakes; there are agricultural and raw-material regions in the north and west. Some of the largest cities of the USA are situated on the Great Lakes; Chicago and Milwaukee are on Lake Michigan; Buffalo and Cleveland are on Lake Erie; the center of the auto industry, Detroit, is on the river of the same name near its entrance into Lake Erie; and the second largest city in Canada, Toronto, is on Lake Ontario. The Great Lakes are joined to the Mississippi River basin by a system of navigable canals that begin near Chicago on Lake Michigan and to the Hudson River (on which New York is located) by a canal beginning in Lake Erie near Buffalo.

The Great Lakes form a deepwater internal shipping route 1,873 km long (from the largest port, Duluth, on Lake Superior to the source of the St. Lawrence River), by means of locks that bypass rapids on the Ste. Marie River (the Sault Ste. Marie Canal) and Niagara Falls on the Niagara river (Welland canal).

As a result of the completion in 1959 of the reconstruction of the canals built to avoid the rapids of the St. Lawrence River, a continuous water route from the Great Lakes to the Atlantic Ocean was created. Its length is about 3,000 km, and its depth is not less than 8 m, thus making it available to large oceangoing vessels. The main flow of cargo is from west to east (wheat and iron ore); the primary freight moving from east to west is coal. The annual freight turnover on the Great Lakes is about 200 million tons, of which more than half takes place in Lake Superior. The freight is carried mainly in ships belonging to American companies. The tonnage of the Canadian Merchant Marine on the Great Lakes constitutes only one-fourth of the total lake fleet tonnage.

REFERENCES

Baulig, H. Severnaia Amerika. Moscow, 1948. (Translated from French.)
Kanada: Geograficheskie raiony. Moscow, 1955. (Translated from English.)
The Laurentian Great Lakes of North America. Uppsala, 1968.

O. A. SPENGLER

Mentioned in	?		References in periodicals archive	?		Encyclopedia browser	?		Full browser	?
No references found			The 56 year-old was seen boarding the Mir-1 submarine before being hoisted into the water to begin his journey into the lake, which is also known as the "Blue Eye of Siberia," and contains more water than all of the North American Great Lakes combined, the AAP reported. Now, 'macho' Putin dives down world's deepest lake by Asian News International Among them are two coastal zones and transitional waters, the North American Great Lakes Basin, Italian lakes, marine ecosystems, and wetlands. Handbook of ecological indicators for assessment of ecosystem health by SciTech Book News Also, a sister ship and exact replica of the German U-boat, was successfully transported from Africa, across the Atlantic, through the North American Great Lakes, and finally through the streets of Chicago - all in one piece - to the city's museum of science and technology. Why new U-boat plan may sink or swim by Liverpool Echo (Liverpool, England)			Norrland Norrland Plateau Norse Norse literature Norse religion Norsemen Norsk H¿stfest Norstad, Lauris norte Norte de Santander Nortel Networks North North Adams North Africa North Africa campaigns North Africa, campaigns in North African Campaigns of 1940–43 north aisle North Albanian Alps North America North American anticyclone North American Basin North American blastomycosis North American Family Campers Association North American Free Trade Agreement North American Great Lakes North American high North American Indian Days North American Indian music North American International Auto Show North American Native art North American Nebula North American presentation-level protocol syntax North American Solar Challenge North American Wife-Carrying Championship North and South Poles North Andover North Arlington North Atlantic Current North Atlantic Drift North Atlantic Treaty Organization North Atlantic Treaty Organization NATO North Attleboro North Augusta North Australia North Ayrshire North Battleford North Bay North Beach North Bellmore North Bend Rail Trail			North American Fruit Explorers North American Fund for Environmental Cooperation North American Fur Association North American Fur Auctions North American Fury Jet Fighter Aircraft North American Fuzzy Information Processing Society North American Gamebird Association North American Gaming Regulators Association North American Gas and Power North American Gay Amateur Athletic Alliance North American Gay Volleyball Association North American General Purpose Attack Weapon North American Geologic Map Data Model North American Ginseng Extract North American Glass Equipment North American Goldwings Forum North American Golf Tour Operators Alliance North American Graduate Art Survey North American Gran Turismo North American Grand Cherokee Association North American Grand Prix North American Graphic Arts Suppliers Association North American Grappling Association North American Grappling Championships North American Great Lakes North American Great Plains North American Green Purchasing Initiative North American Guaranty Corporation North American Guidelines for Children's Agricultural Tasks North American Guild of Beer Writers North American Guild of Change Ringers North American Gun Dog Association North American Gypsy Moth North American hackberries North American hackberries North American Hair Research Society North American Hair Sheep Association North American Halloween Prevention Initiative North American Handicapped Riding Association North American Hardcore Movement North American Hazardous Materials Management Association North American Health Plans, Inc. North American Heather Society North American Help Desk North American High North American Hindu Association North American Historians of Islamic Art North American Hobie Class Association North American Hockey Academy North American Hockey League

Great Lakes (redirected from North American Great Lakes)

Bibliography

Great Lakes

Great Lakes

REFERENCES

Great Lakes
(redirected from North American Great Lakes)