The Great Lakes Region
This view of the Great Lakes region was captured on June 1, 2008 by the MODIS on the Terra satellite. Visible in the image is Lake Superior (top), Lake Michigan (bottom), and Lake Huron (right). The states of Michigan, Wisconsin, Illinois, Indiana, and part of Canada are also visible.
The blue/green coloration in Lake Michigan is likely due to the calcium carbonate (or chalk) in the water. The amount of it changes seasonally, and colors the water when there are increased amounts of it.