Lake Superior

Jai Ganesh · 2025-07-31 22:11:00

Lake Superior

Gist:

Lake Superior, featured in National Geographic, is the largest of the Great Lakes by surface area. It's known for its vast size, deep waters, and the Ojibwe name "Gitche Gumee," meaning "Great Sea". The lake is shared by Canada and the United States, with shorelines in Ontario, Minnesota, Wisconsin, and Michigan.

8 Fun Facts About Lake Superior

* Lake Superior Holds 10% of the Planet's Fresh Water. ...
* The Lake Covers Over 31,700 Square Miles. ...
* You Can Really See Your Way Around in the Waters. ...
* Summer Days are Longer on the Western Shore of Lake Superior. ...
* The Lake Hardly Ever Freezes Entirely. ...
* Superior is Full of Surprises.

Summary

1. Lake Superior is, by surface area, the world's largest freshwater lake.
2. The surface area of Lake Superior (31,700 square miles or 82,170 square kilometers) is greater than the combined areas of Vermont, Massachusetts, Rhode Island, Connecticut, and New Hampshire.
3. Lake Superior contains as much water as all the other Great Lakes combined, even throwing in two extra Lake Eries. Its volume is second only to Russia's Lake Baikal.
4. Lake Superior contains 10% of all the earth's fresh surface water.
5. There is enough water in Lake Superior (3,000,000,000,000,000--or 3 quadrillion-- gallons) to flood all of North and South America to a depth of one foot.
6. The deepest point in Lake Superior (about 40 miles north of Munising, Michigan) is 1,300 feet (400 meters) below the surface.
7. Over 300 streams and rivers empty into Lake Superior.
8, The average elevation of Lake Superior is about 602 feet above sea level.
9. The Lake Superior watershed region ranges in size from 160 miles inland near Wabakimi Provincial Park to only 5 miles inland from Pictured Rocks National Seashore.
10. The Lake Superior shoreline, if straightened out, could connect Duluth and the Bahama Islands.
11. The average underwater visibility of Lake Superior is 27 feet, making it easily the cleanest and clearest of the Great Lakes. Underwater visibility in places reaches 100 feet. Lake Superior has been described as "the most oligotrophic lake in the world."
12. The lake is about 350 miles (563 km) in length and 160 miles (257 km) in width.
13. In the summer, the sun sets more than 35 minutes later on the western shore of Lake Superior than at its southeastern edge.
14. Lake Superior has over 400 islands, the largest of which is Isle Royale, with a size of 207 square miles.
15. Waves of over 40 feet in height have been recorded on Lake Superior.
16. Travel by car around Lake Superior covers a distance of about 1,300 miles.
17. The largest underwater formation in Lake Superior is the Superior Shoal, which rises from a depth of over 1,000 feet to within 20 feet of the water surface over a distance of just three miles.
18. Sudden changes in winds or barometric pressure around Lake Superior can produce seiches, a phenomenon which results in water levels rising or falling as much as six feet along a coast in a short period of time.
19. Water in Lake Superior is retained, on average, 191 years.
20. Generations have been lured to this rugged coast for its incredible scenery, clear waters, agate beaches and vibrant cultural history. Lake Superior is often called the greatest of the Great Lakes—and with good reason: With a surface area of 31,700 square miles, it is the largest freshwater lake in the world.

Details

Lake Superior is a lake in central North America. The northernmost, westernmost, and highest of the Great Lakes, Lake Superior straddles the Canada–United States border with the Canadian province of Ontario to the north and east and the U.S. states of Minnesota to the west and Michigan and Wisconsin to the south. It is the largest freshwater lake in the world by surface area and the third-largest freshwater lake by volume, holding 10% of the fresh water in all of the world's rivers and lakes. It drains into Lake Huron via St. Marys River, then through the lower Great Lakes to the St. Lawrence River and ultimately the Atlantic Ocean.

Name

In the 17th century, the first French explorers approached the great inland sea by way of the Ottawa River and Lake Huron; they referred to their discovery as le lac supérieur (the upper lake, i.e., above Lake Huron in elevation). Some 17th-century Jesuit missionaries referred to it as Lac Tracy (for Alexandre de Prouville de Tracy). After taking control of the region from the French in the 1760s, following their defeat in the French and Indian War, the British anglicized the lake's name to Superior, "on account of its being superior in magnitude to any of the lakes on that vast continent".

Hydrography

Lake Superior empties into Lake Huron via the St. Marys River and the Soo Locks (Sault Ste. Marie locks). Lake Superior is the largest freshwater lake in the world by area and the third largest in volume, behind Lake Baikal in Siberia and Lake Tanganyika in East Africa. The Caspian Sea, while larger than Lake Superior in both surface area and volume, is brackish.

Lake Superior has a surface area of 31,700 square miles (82,103 sq km), which is approximately the size of South Carolina or Austria. It has a maximum length of 350 statute miles (560 km; 300 nmi) and maximum breadth of 160 statute miles (257 km; 139 nmi). Its average depth is 80.5 fathoms (483 ft; 147 m) with a maximum depth of 222.17 fathoms (1,333 ft; 406 m). Lake Superior contains 2,900 cubic miles (12,100 km3) of water. There is enough water in Lake Superior to cover the entire land mass of North and South America to a depth of 30 centimetres (12 in). The shoreline of the lake stretches 2,726 miles (4,387 km) (including islands). The lake boasts a very small ratio (1.55) of catchment area to surface area, which indicates minimal terrestrial influence.

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, which at 122 fathoms 1-foot (733 ft or 223 m) below sea level is the second-lowest spot in the continental interior of the United States and the third-lowest spot in the interior of the North American continent after Great Slave Lake in the Northwest Territories of Canada (1,503 ft or 458 m below sea level) and Iliamna Lake in Alaska 942 ft or 287 m. (Though Crater Lake is the deepest lake in the United States and deeper than Lake Superior, Crater Lake's elevation is higher and consequently its deepest point is 4,229 feet (1,289 m) above sea level.)

While the temperature of the surface of Lake Superior varies seasonally, the temperature below 110 fathoms (660 ft; 200 m) is an almost constant 39 °F (4 °C). This variation in temperature makes the lake seasonally stratified. Twice per year, however, the water column reaches a uniform temperature of 39 °F (4 °C) from top to bottom, and the lake waters thoroughly mix. This feature makes the lake dimictic. Because of its volume, Lake Superior has a retention time of 191 years.

Annual storms on Lake Superior regularly feature wave heights of over 20 feet (6 m). Waves well over 30 feet (9 m) have been recorded.

Tributaries

Lake Superior is fed by more than 200 rivers, including the Nipigon River, the St. Louis River, the Pigeon River, the Pic River, the White River, the Michipicoten River, the Bois Brule River and the Kaministiquia River. The lake's outlet at St. Marys River has a relatively steep gradient with rapids. The Soo Locks enable ships to bypass the rapids and to overcome the 25-foot (8 m) height difference between Lakes Superior and Huron.

Water levels

The lake's average surface elevation is 600 feet (183 m) above sea level. Until approximately 1887, the natural hydraulic conveyance through the St. Marys River rapids determined the outflow from Lake Superior. By 1921, development in support of transportation and hydroelectric power resulted in gates, locks, power canals and other control structures completely spanning St. Marys rapids. The regulating structure is known as the Compensating Works and is operated according to a regulation plan known as Plan 1977-A. Water levels, including diversions of water from the Hudson Bay watershed, are regulated by the International Lake Superior Board of Control, which was established in 1914 by the International Joint Commission.

Lake Superior's water level was at a new record low eptember 2007, slightly less than the previous record low in 1926. Water levels recovered within a few days.

The lake's water level fluctuates from month to month, with the highest lake levels in October and November. The normal high-water mark is 1.17 feet (0.36 m) above the datum (601.1 ft or 183.2 m). In the summer of 1985, Lake Superior reached its highest recorded level at 2.33 feet (0.71 m) above the datum. 2019 and 2020 set new high-water records in nearly every month.

The lake's lowest levels occur in March and April. The normal low-water mark is 0.33 feet (0.10 m) below the datum. In the winter of 1926, Lake Superior reached its lowest recorded level at 1.58 feet (0.48 m) below the datum. Additionally, the entire first half of the year (January to June) included record low months. The low water was a continuation of the dropping lake levels from the previous year, 1925, which set low-water records for October through December. During the nine-month period of October 1925 to June 1926, water levels ranged from 1.58 to 0.33 feet (0.48 to 0.10 m) below Chart Datum. In the summer of 2007 monthly historic lows were set; August at 0.66 feet (0.20 m), and September at 0.58 feet (0.18 m).

Climate change

According to a study by professors at the University of Minnesota Duluth, Lake Superior may have warmed faster than its surrounding area. Summer surface temperatures in the lake appeared to have increased by about 4.5 °F (2.5 °C) between 1979 and 2007, compared with an approximately 2.7 °F (1.5 °C) increase in the surrounding average air temperature. The increase in the lake's surface temperature may be related to the decreasing ice cover. Less winter ice cover allows more solar radiation to penetrate and warm the water. If trends continue, Lake Superior, which freezes over completely once every 20 years, could routinely be ice-free by 2040 although more current data through 2021 does not support this trend.

Warmer temperatures could lead to more snow in the lake effect snow belts along the shores of the lake, especially in the Upper Peninsula of Michigan. Two recent consecutive winters (2013–2014 and 2014–2015) brought high ice coverage to the Great Lakes, and on March 6, 2014, overall ice coverage peaked at 92.5%, the second-highest in recorded history. Lake Superior's ice coverage further beat 2014's record in 2019, reaching 95% coverage.

Geography

The largest island in Lake Superior is Isle Royale in Michigan. Isle Royale contains several lakes, some of which also contain islands. Other well-known islands include Madeline Island in Wisconsin, Michipicoten Island in Ontario, and Grand Island (the location of the Grand Island National Recreation Area) in Michigan.

The larger cities on Lake Superior include the twin ports of Duluth, Minnesota, and Superior, Wisconsin; Thunder Bay, Ontario; Marquette, Michigan; and the twin cities of Sault Ste. Marie, Michigan, and Sault Ste. Marie, Ontario. Duluth-Superior, at the western end 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 Apostle Islands National Lakeshore, Brockway Mountain Drive on the Keweenaw Peninsula, Isle Royale National Park, Porcupine Mountains Wilderness State Park, Pukaskwa National Park, Lake Superior Provincial Park, Grand Island National Recreation Area, Sleeping Giant (Ontario) and Pictured Rocks National Lakeshore. The Great Lakes Circle Tour is a designated scenic road system connecting all of the Great Lakes and the St. Lawrence River.

Additional Information

Lake Superior, most northwesterly and largest of the five Great Lakes of North America and one of the world’s largest bodies of fresh water. Its name is from the French Lac Supérieur (“Upper Lake”). Bounded on the east and north by Ontario (Canada), on the west by Minnesota (U.S.), and on the south by Wisconsin and Michigan (U.S.), it discharges into Lake Huron at its eastern end via the St. Marys River. Lake Superior is 350 miles (563 km) long (east to west), and its greatest width is 160 miles (258 km) from north to south. It has a mean surface elevation of 600 feet (180 metres) above sea level and a maximum depth of 1,332 feet (406 metres). The lake’s drainage basin is 49,300 square miles (127,700 square km), exclusive of its surface area of 31,700 square miles (82,100 square km). The lake is so massive and its volume so large that, were it to be emptied at its current rate (with no compensating additions of water), it would take 191 years. Because of its large size (relative to watershed area) and the porous “dam” at its outlet, long-term lake-level fluctuations are much lower than in any of the other Great Lakes—generally less than 1 yard (1 metre). Annual lake-level fluctuations are less than 12 inches (30 cm).

Lake Superior receives water from approximately 200 rivers, of which the largest are the Nipigon (from the north) and the St. Louis (from the west). Other principal rivers entering the north shore are the Pigeon, Kaministikwia, Pic, White, and Michipicoten. No large rivers enter the lake from the south; the middle-sized Sturgeon and Tahquamenon rivers are the main south-shore tributaries. Small amounts of water are also diverted into the lake from two places otherwise outside of the watershed—Long Lac and Ogoki—in order to accentuate hydroelectric power generation at Sault Sainte Marie, Michigan, and Niagara Falls.

The principal islands in the lake are Isle Royale, a U.S. national park; the Apostle Islands, near the Wisconsin shore; Michipicoten, on the east side; and St. Ignace, near the mouth of the Nipigon River (Canada).

The coastline of Lake Superior is picturesque, particularly the north shore, which is indented by deep bays backed by high cliffs. Much of the coastal area is sparsely settled. Extensive forests, which dominate the watershed, are held in federal, state, provincial, and private timberlands. Seasonal hunting, sportfishing, and tourism form the basis for an important regional recreation industry.

Valuable mineral deposits surround the lake. Iron ore was mined and smelted locally from 1848, and the opening (1855) of the Soo Locks ship canal on the St. Marys River facilitated iron mining in the region by allowing regular shipment to the lower lakes. Subsequently, iron was extracted from many parts of the Lake Superior district, including the Marquette Range in Michigan and the Mesabi Range in Minnesota. Only taconite and other low-grade ores are now mined and enriched on site. Other minerals extracted include silver (near Thunder Bay, Ontario), nickel (north of the lake), and copper (south of the lake). In the late 1800s a small “gold rush” took place on its southern shore in Michigan.

Lake Superior has many natural harbours, and improvements have created additional ports. The navigation season is generally about eight months long. At Thunder Bay, grain from the Canadian prairies is transferred from rail to ship. Iron ore is exported from Taconite Harbor and Two Harbors (Minnesota) and from Marquette (Michigan). The harbour shared by Duluth (Minnesota) and Superior (Wisconsin) is a shipping point for iron ore, grain, and flour. The principal ports along the lake’s south shore are Ashland (Wisconsin), Hancock and Houghton (both on a 25-mile- (40-km-) long canal across the Keweenaw Peninsula, Michigan), and Marquette. All boat traffic that leaves the lake for southern ports must pass through the Soo Locks at Sault Sainte Marie.

The first European to see Lake Superior was probably the French explorer Étienne Brûlé in 1622. Pierre Espirit Radisson and Médard Chouart des Groseilliers gathered a valuable cargo of furs during their extensive travels on the lake (1659–60). The French Jesuit missionary Claude-Jean Allouez circumnavigated and charted the lake in 1667. Daniel Greysolon, sieur (lord) DuLhut (or Du Luth), opened the lake to active trading in 1679. French fur trading then flourished at intervals, but the entire region came under British control between 1763 and 1783. Trade remained in the hands of the British until 1817, when John Jacob Astor’s American Fur Company took over south of the Canadian border.

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#1 2025-07-31 22:11:00

Lake Superior

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