They hold about 6 quadrillion gallons of water, or enough to blanket the entire U.S. to a depth of ... Below is a chart that shows the average date of first ice on the Great Lakes.

The U.S. Army Corps of Engineers predicts Great Lakes water levels will rise seasonally ... enough to allow their levels to fluctuate similarly. In February, the lakes had a minimum depth of 600.62 ...

Photo courtesy of Matt Zuro. Image from NWS webpage. The Laurentian Great Lakes, as the world's largest unfrozen surface freshwater system, hold paramount significance in maintaining the ecological ...