|MadSci Network: Earth Sciences|
Larry, That is a very interesting question - you probably won't believe the answer because it is so huge!!!!!!! This is information I got from the US Geological survey page, which can be found at - http://wwwga.usgs.gov/edu/earthhowmuch.html The total water supply of the world is 326 million cubic miles (a cubic mile is an imaginary cube (a square box) measuring one mile on each side). A cubic mile of water equals more than one trillion gallons. One cubic mile = 1,000,000,000,000 gallons so the earth has - 326,000,000,000,000,000,000 gallons. About 3,100 cubic miles of water, mostly in the form of water vapor, is in the atmosphere at any one time. If it all fell as precipitation at once, the Earth would be covered with only about 1 inch of water. The 48 contiguous United States receives a total volume of about 4 cubic miles of precipitation each day. Each day, 280 cubic miles of water evaporate or transpire into the atmosphere. If all of the world's water was poured on the United States, it would cover the land to a depth of 90 miles. Of the freshwater on Earth, much more is stored in the ground than is available in lakes and rivers. More than 2,000,000 cubic miles of fresh water is stored in the Earth, most within one-half mile of the surface. Contrast that with the 60,000 cubic miles of water stored as fresh water in lakes, inland seas, and rivers. But, if you really want to find fresh water, the most is stored in the 7,000,000 cubic miles of water found in glaciers and icecaps, mainly in the polar regions and in Greenland. Hope this helps ... and thanks for using the Mad Scientists :o) DrJim
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