Ojibwe’s “great sea” is the world’s largest freshwater surface
Lake Superior—gichi-gami, the Ojibwe “great sea”—covers about 31,700 square miles, the largest freshwater lake by area on Earth. French explorers called it lac supérieur because it sits above Huron; it still feeds that lower lake through the St. Marys River and Soo Locks.
Northernmost, westernmost, and highest of the Great Lakes, it borders Ontario, Minnesota, Wisconsin, and Michigan. Maximum length reaches 350 miles and breadth 160; average depth is about 483 feet, with deep water below 660 feet locked near a constant 39 °F. Volume ranks third worldwide behind Baikal and Tanganyika. Surface elevation averages 600 feet. Father Frederic Baraga’s 1853 dictionary, the first ever compiled for Ojibwe, renders the name as Otchipwe-kitchi-gami.
Limnologist J. Val Klump reached the deepest point on 30 July 1985, 733 feet below sea level—among the continent’s lowest interior spots. More than 200 rivers enter, from the Nipigon and St. Louis to the Kaministiquia; storms regularly raise twenty-foot waves and sometimes thirty. Longfellow’s “Gitche Gumee” and Lightfoot’s Edmund Fitzgerald ballad carried the Ojibwe name into popular English. Isle Royale in Michigan is its largest island and even holds lakes with islands of their own.
Natural St. Marys rapids once set the outflow until late-nineteenth- and early-twentieth-century navigation and power works fixed the discharge. Levels usually peak in October and November and fall lowest in March and April; the highest reading came in summer 1985 at 2.33 feet above datum, and the lowest in winter 1926 at 1.58 feet below, narrowly undercut in September 2007 before recovering within days.
Researchers at the University of Minnesota Duluth found summer surface water warming by about 4.5 °F between 1979 and 2007, faster than the surrounding air. Cold winters still bite: ice covered 95 percent of the lake in 2019. At its western tip, Duluth and Superior form the most inland port on the planet and the deepest reach of the Saint Lawrence Seaway.
Source: Lake Superior
