Lake Superior

Lake Superior, bounded by Ontario, Canada and Minnesota, USA, to the north and Wisconsin and Michigan, USA, to the south, is the largest of North America's Great Lakes. It is the largest freshwater lake in the world by surface area and is the world's fourth-largest freshwater lake by volume.^[2]

Name

In the Ojibwe language, the lake is called "Gichigami" ("big water"), but it is better known as "Gitche Gumee" as recorded by Henry Wadsworth Longfellow in The Song of Hiawatha. Lake Superior is referred to as "Gitche Gumee" in the song The Wreck of the Edmund Fitzgerald, by Gordon Lightfoot.

The lake was named le lac supérieur, or "Upper Lake," in the seventeenth century by French explorers because it was located above Lake Huron.(Nute, 1946)

Hydrography

Lake Superior is the largest freshwater lake in the world by surface area. Lake Baikal in Russia is larger by volume, as is Lake Tanganyika. The Caspian Sea, while vastly larger than Lake Superior in both surface area and volume, is saline; though presently isolated, in the past, it has been repeatedly connected to, and isolated from, the Mediterranean via the Black Sea.

Lake Superior (48°00’N, 88°00’W) has a surface area of 31,820 square miles (82,414 km²)^[1]—which is larger than South Carolina. It has a maximum length of 350 miles (563 km) and maximum breadth of 160 miles (257 km). Its average depth is 483 feet (147 m) with a maximum depth of 1,333 feet (406 m).^[1] Lake Superior contains 2,900 cu mi (12,100 km³) of water. There is enough water in Lake Superior to cover the entire land mass of North and South America with a foot (30 cm) of water. The shoreline of the lake stretches 2,726 miles (4,385 km) (including islands). The lake's elevation is 600 feet (183 m)^[1] above sea level. American limnologist J. Val Klump was the first person to reach the lowest depth of Lake Superior on July 30, 1985 as part of a scientific expedition.

Annual storms on Lake Superior regularly record wave heights of over 20 feet (6 m). [1]

Water levels, including diversions of water from the Hudson Bay watershed, are governed by the International Lake Superior Board of Control which was established in 1914 by the International Joint Commission.

Tributaries and outlet

The lake is fed by over 200 rivers. The largest include the Nipigon River, the St. Louis River, the Pigeon River, the Pic River, the White River, the Michipicoten River, the Brule River and the Kaministiquia River. Lake Superior drains into Lake Huron by the St. Marys River. The rapids on the river necessitate the Sault Locks (pronounced "soo"), a part of the Great Lakes Waterway, to move boats over the 25 foot (7.6 m) height difference from Lake Huron.

Geography

The largest island in Lake Superior is Isle Royale in the state of Michigan. Other large famous islands include Madeline Island in the state of Wisconsin and Michipicoten in the province of Ontario.

The larger towns on Lake Superior include: the twin ports of Duluth, Minnesota and Superior, Wisconsin; Thunder Bay, Ontario; Marquette, Michigan; and the two cities of Sault Ste. Marie, in Michigan and in Ontario. Duluth, at the western tip of Lake Superior, is the most inland point on the Saint Lawrence Seaway and the most inland port in the world.

Among the scenic places on the lake are: the Apostle Islands National Lakeshore; Isle Royale National Park; Pukaskwa National Park; Lake Superior Provincial Park; Grand Island National Recreation Area; Sleeping Giant (Ontario);and Pictured Rocks National Lakeshore.

Geology

The lake lies above a long-extinct Mesoproterozoic rift valley, the Midcontinent Rift, which explains its great depths.

The land surrounding the lake has proved to be rich in minerals. Copper, iron, silver, gold and nickel are or were the most frequently mined.

History

The Anishinabe, also known as the Ojibwe or Chippewa, have inhabited the Lake Superior region for over five hundred years, and were preceded by the Dakota, Fox, Menominee, Nipigon, Noquet, and Gros Ventres.

Many towns around the lake are either current or former mining areas, or engaged in processing or shipping. Today, tourism is another significant industry as the sparsely populated Lake Superior country, with its rugged shorelines and wilderness, attracts tourists and adventurers.

Shipping

Lake Superior has been an important link in the Great Lakes Waterway, providing a route for the transportation of iron ore and other mined and manufactured materials. Large cargo vessels called lake freighters, as well as smaller ocean-going freighters, transport these commodities across Lake Superior.

Shipwrecks

The last major shipwreck on Lake Superior was that of SS Edmund Fitzgerald in 1975.

According to an old sailor's tale, Lake Superior never gives up her dead. This is due to the temperature of the water. Normally bacteria feeding off a sunken decaying body will generate gas inside the body, causing it to float to the surface after a few days. The water in Lake Superior however, is cold enough year-round to inhibit bacterial growth, meaning bodies tend to sink and never surface. This is poetically referenced in Gordon Lightfoot's famous ballad, The Wreck of the Edmund Fitzgerald.

Ecology

Although part of a single system, each of the Great Lakes is different. In volume, Lake Superior is the largest. It is also the deepest and coldest of the five. Superior could contain all the other Great Lakes and three more Lake Eries. Because of its size, Superior has a retention time of 191 years.

References

See also

• the North Shore of Lake Superior
• the South Shore of Lake Superior

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