Profile of the Great Lakes

From left to right, Lake Superior, the deepest, Lake Michigan and Lake Huron at the same sea level and considered one lake, shallow Lake Erie, and Lake Ontario.  This illustration shows how the Great Lakes are one flowing river of seas that follow gravity down then flow through the St. Lawrence River and empty into the Atlantic Ocean.

Read more about this system of lakes in my critically acclaimed book, The Dynamic Great Lakes widely available on the www and in independent bookstores.

NOAA Chart showing depths of Lake Michigan

Lake Michigan's depths: red shallow, dark blue the deepest part.  Lake Michigan is divided into two basins.  Where you see a change from green to dark blue shows the two basins.  It takes 99 years for the water to circulate out of Lake Michigan from the south to the north.  That's why it is important to keep pollutants out of the Lake.  Read more about the circulation of water and more in my book, The Dynamic Great Lakes available in bookstores and on line at Amazon.com and Barnes & Noble as well as many other venues.