The Great Lakes

THE GREAT LAKES

The 5 Great Lakes (Lake Erie, Lake Huron, Lake Michigan, Lake Ontario, and Lake Superior) in North America is the largest group of freshwater lakes in the world.

The present configuration of the Great Lakes basin is the result of the movement of massive glaciers through the mid-continent, a process that began about one million years ago. . . . Studies in the Lake Superior region indicate that a river system and valleys formed by water erosion existed before the Ice Age. The glaciers undoubtedly scoured these valleys, widening and deepening them and radically changing the drainage of the area. (Great Lakes, 2007)

Physical Features

The Great Lakes have a combined area of 94,510 square miles (244,780 square kilometers). Althrough the Great Lakes were all formed by glacial activity during the same period, they are quit different from one another. The irregular movement of the glacier created variation is the size, elevation, and depth of the lakes.

Lake Superior, the largest of the lakes, is only slightly smaller than Maine; and Lake Ontario, the smallest of the lakes, is abot the size of New Jersey.

The lakes vary greatly in elevation. Lake Superior, the highest, lies 600 feet (183 meters) above sea level, while Lake Ontario, the lowest, lyes just 245 feet (75 meters) above sea level. There is a 325- foot diference in elevation between Lakes Erie and Ontario. Most of the water from the lakes drains into the St. Lawrence River, which flows into the Atlantic Ocean (The World Almanac and Book of Facts, 2007, p. 707.

The depth of the Great Lakes varies greatly, too. The deepest, Lake Superior, is 1,333 feet (406 meters) deep. Lake Erie, the shallowest, is only 210 feet (64 meters) deep (New York Times Almanac, 2007, p. 64).

Connecting Waterways

Three sets of locks and canals make it possible for ships to sail from one Great Lake to another and from Lake Ontario to the Atlantic Ocean, from which they can sail to any prot in the world. The canal and the bodies of water they connect are listed here.

Welland Canal--connects Lake Erie and Lake Ontario.

Soo Canal--connects Lake Superior & Lake Huron.

St. Lawrence Seaway--connects Lake Ontario with the Atlantic Ocean.

Significance of the Lakes

The five Great Lakes and the canals that link them together make up the most important inland waterway in North America. They provide the inexpensive transportation system needed to make the Great Lakes region one of the most important industrial areas in the United States.

References

“Great Lakes.” Encyclopædia Britannica. (14 July 2007). The New York Times Almanac. “Great Lakes and St. Lawrence Seaway.” New York: Penguin Books, 2007.

The World Almanac and Book of Facts. “The Great Lakes.” New York: World Almanac Books, 2007.