Total de água na superfície da Terra

Synopsis: The planet Earth is made of water? Very little. Although ocean water covering about 70 percent of the surface of the Earth, these are shallow seas compared to the radius of the Earth. The illustration shows what would happen if all the water on or near the earth's surface were gathered into a ball. Its radius would be only about 700 km, less than half the radius of the Moon.
Source: NASA (adapted).
URL: http://apod.nasa.gov/apod/ap120515.html