View of Lake Michigan, USA – October 15th, 2008
Lake Michigan is one of the five Great Lakes of North America. It is the only Great Lake located completely within the borders of the United States; the others are shared with Canada. It is bounded, from west to east, by the U.S. states of Wisconsin, Illinois, Indiana, and Michigan.
The lake is slightly larger than the country of Croatia. It has a surface area of 22,400 square miles (58,016 km²), making it the largest lake entirely within one country by surface area, and the fifth largest lake in the world. It is 307 miles (494 km) long by 118 miles (190 km) wide with a shoreline 1,640 miles (2,633 km) long. The lake’s average depth is 279 feet (85 m), while its greatest depth is 923 feet (281 m).
In the image we can see Lake Michigan (to the left), as well as Lake Huron (to the right) and a section of Lake Erie (far right). Geologically and hydrologically, Michigan and Huron are the same body of water (sometimes called Lake Michigan-Huron), but are geographically distinct. Counted together, it is the largest fresh water body in the world by surface area. The Mackinac Bridge is generally considered the dividing line between them. The city of Chicage is also visible on the western side of the southern shore of Lake Michigan.
The Milwaukee Reef, running under Lake Michigan from Milwaukee to a point between Grand Haven and Muskegon (both cities in the middle of the eastern lake shore), divides the lake into northern and southern pools. Each pool has a counterclockwise flow of water, deriving from rivers, winds, and the Coriolis effect. Prevailing westerly winds tend to move the surface water toward the east, producing a moderating effect on the climate of western Michigan. There is a mean difference in summer temperatures of 5 to 10 degrees between the Wisconsin and Michigan shores.