USGS - science for a changing world

The USGS Water Science School

The World's Water

"Water, Water, Everywhere...."
You've heard the phrase, and for water, it really is true. Earth's water is (almost) everywhere: above the Earth in the air and clouds, on the surface of the Earth in rivers, oceans, ice, plants, in living organisms, and inside the Earth in the top few miles of the ground.

Below are two representations of where Earth's water resides. The left-side bar chart shows how almost all of Earth's water is saline and is found in the oceans. Of the small amount that is actually freshwater, only a relatively small portion is available to sustain human, plant, and animal life.

The globe image represents how much actual water exists, compared to the total size of the Earth. Notice the blue spheres (representing water). They look small because they are being compared to the size of the whole globe. The image shows that Earth's water resides in a very thin slice all around the Earth's surface.

Distribution of Earth's Water

View a larger version of this image and learn more.

All of the World's Water

Picture of the globe with all the water in a large ball.

Earth's freshwater

Spheres showing:
(1) All water (sphere over western U.S., 860 miles in diameter)
(2) Fresh liquid water in the ground, lakes, swamps, and rivers (sphere over Kentucky, 169.5 miles in diameter), and
(3) Fresh-water lakes and rivers (sphere over Georgia, 34.9 miles in diameter).
Credit: Howard Perlman, USGS; globe illustration by Jack Cook, Woods Hole Oceanographic Institution (©); Adam Nieman.

One estimate of global water distribution
(Percents are rounded, so will not add to 100)
Water sourceWater volume, in cubic milesWater volume, in cubic kilometersPercent of
Percent of
total water
Oceans, Seas, & Bays321,000,0001,338,000,000--96.5
Ice caps, Glaciers, & Permanent Snow5,773,00024,064,00068.71.74
Ground water5,614,00023,400,000--1.69
    Fresh2,526,00010,530,00030.1  0.76
    Saline3,088,00012,870,000--  0.93
Soil Moisture3,95916,5000.050.001
Ground Ice & Permafrost71,970300,0000.860.022
Swamp Water2,75211,4700.030.0008
Biological Water2691,1200.0030.0001
Source: Igor Shiklomanov's chapter "World fresh water resources" in Peter H. Gleick (editor), 1993, Water in Crisis: A Guide to the World's Fresh Water Resources (Oxford University Press, New York).

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Howard Perlman
Page Last Modified: Thursday, 30-Jul-2015 14:15:04 EDT