Great Lakes

Great Lakes of North America
Great Lakes
Five continent-sized lakes
The Great Lakes seen from NASA's Aqua satellite in August 2010. From left to right: Lake Superior, Michigan, Huron, Erie, Ontario
Bathymetry map of the Great Lakes
LocationEastern North America
Coordinates45°N 84°W / 45°N 84°W / 45; -84
Typegroup of interconnected freshwater lakes
Part ofGreat Lakes Basin
Primary inflowsPast: precipitation and meltwater
Now: rivers, precipitation, and groundwater springs
Primary outflowsEvaporation, St. Lawrence River to the Atlantic Ocean
Basin countriesCanada, United States
Surface area94,250 square miles (244,106 km2)
Average depth60–480 ft (18–146 m) depending on the lakes
Max. depth210–1,300 ft (64–396 m) depending on the lakes
Water volume5,439 cubic miles (22,671 km3) (lowest)
Frozenaround January to March

The Great Lakes (French: Grands Lacs), also called the Great Lakes of North America, are a series of large interconnected freshwater lakes spanning the Canada–United States border. The five lakes are Superior, Michigan, Huron, Erie, and Ontario. (Hydrologically, Michigan and Huron are a single body of water, as they are joined by Straits of Mackinac.) The Great Lakes Waterway enables modern travel and shipping by water among the lakes. The lakes connect to the Atlantic Ocean via the Saint Lawrence River, and to the Mississippi River basin through the Illinois Waterway.

The Great Lakes are the largest group of freshwater lakes on Earth by total area and the second-largest by total volume. They contain 21% of the world's surface fresh water by volume.[1][2][3] The total surface is 94,250 square miles (244,106 km2), and the total volume (measured at the low water datum) is 5,439 cubic miles (22,671 km3),[4] slightly less than the volume of Lake Baikal (5,666 cu mi or 23,615 km3, 22–23% of the world's surface fresh water). Because of their sea-like characteristics, such as rolling waves, sustained winds, strong currents, great depths, and distant horizons, the five Great Lakes have long been called inland seas.[5] Depending on how it is measured, by surface area, either Lake Superior or Lake Michigan–Huron is the second-largest lake in the world and the largest freshwater lake. Lake Michigan is the largest lake, by surface area, that is entirely within one country, the United States.[6][7][8][9]

The Great Lakes began to form at the end of the Last Glacial Period around 14,000 years ago, as retreating ice sheets exposed the basins they had carved into the land, which then filled with meltwater.[10] The lakes have been a major source for transportation, migration, trade, and fishing, serving as a habitat to many aquatic species in a region with much biodiversity. The surrounding region is called the Great Lakes region, which includes the Great Lakes Megalopolis.[11] Major cities within the region include, on the American side, from east to west, Buffalo, Cleveland, Detroit, Chicago, and Milwaukee; and, on the Canadian side, Toronto, Hamilton and Mississauga.

  1. ^ "Great Lakes". U.S. Environmental Protection Agency. June 28, 2006. Retrieved February 19, 2011.
  2. ^ "LUHNA Chapter 6: Historical Landcover Changes in the Great Lakes Region". USGS: Ecosystems. November 20, 2003. Archived from the original on January 11, 2012. Retrieved February 19, 2011.
  3. ^ Ghassemi, Fereidoun (2007). Inter-basin water transfer. Cambridge: Cambridge University Press. ISBN 978-0-521-86969-0.
  4. ^ "Great Lakes: Basic Information: Physical Facts". U.S. Environmental Protection Agency. May 25, 2011. Archived from the original on May 29, 2012. Retrieved November 9, 2011.
  5. ^ Williamson, James (2007). The inland seas of North America: and the natural and industrial productions ... John Duff Montreal Hew Ramsay Toronto AH Armour and Co. ISBN 9780665341281. Retrieved January 5, 2014.
  6. ^ "The Top Ten: The Ten Largest Lakes of the World". infoplease.com.
  7. ^ Rosenberg, Matt. "Largest Lakes in the World by Area, Volume and Depth". About.com Education. Archived from the original on February 17, 2017. Retrieved January 30, 2015.
  8. ^ Hough, Jack (1970) [1763]. "Great Lakes". Encyclopædia Britannica. Vol. 10 (Commemorative Edition for Expo'70 ed.). Chicago: William Benton. p. 774. ISBN 978-0-85229-135-1.
  9. ^ "Large Lakes of the World". factmonster.com.
  10. ^ Cordell, Linda S.; Lightfoot, Kent; McManamon, Francis; Milner, George (2008). Archaeology in America: An Encyclopedia. ABC-CLIO. p. 1. ISBN 978-0-313-02189-3.
  11. ^ "Great Lakes". America 2050. Archived from the original on February 20, 2020. Retrieved December 7, 2016.