How Much Water?

Earth, the blue planet.  Sure, we found other planets that have, in one way or another, some form of water; however, as we know it, no other ‘rock’ flying around the universe holds the necessary supply of water to support life.  With this introduction, I am starting a series of blogs on water.  To start, we will explore how much water is on Earth.

According to the United States Geological Survey (USGS, a section of the Department of the Interior, DOI) there are about 332,500,000 cubic miles of water.  OK, great!, but how do you try to envision this enormous volume of water.  Try this, in your mind, image a fence that is 1 mile long (feel free to measure a major freeway on Google Earth if you want a more accurate mental picture).  OK, got it.  Now, using 3 more sections of fence, draw a square.  Now, instead of just a fence, turn it into a building that each side is one mile long, but also is one mile tall.  This structure we have just imagined in 1 cubic mile.  So if this structure were a bucket, it would hold 1 cubic mile of water.   Now, imagine 300 million of these buckets.  That is the approximate amount of water on Earth. This water makes up our oceans, lakes, rivers, clouds, plants, underground, our bodies, and everything else.  Next, we will look at where all this water is.

Source:

USGS Water information page:  http://ga.water.usgs.gov/edu/earthhowmuch.html