Antarctica has lost a significant amount of ice in the past few years, find Isabella Velicogna and John Wahr of the University of Colorado at Boulder. They used measurements taken from April 2002 to August 2005 by the Gravity Recovery and Climate Experiment (GRACE). It consists of two orbiting satellites whose separation is affected by slight gravitational tugs caused by the shifting of mass on the earth's surface. The changes can be measured to an accuracy of one micron.

Percent of the earth's freshwater in Antarctica: 70

Percent of the earth's ice in Antarctica: 90

Cubic kilometers of ice lost annually during study period: 152

In gallons: 40 trillion

Time needed by U.S. to consume that amount of water: 3 months

Resulting contribution to annual rise in sea level: 0.4 millimeter

Margin of error: 0.2 millimeter

Percent of total sea-level rise during study period accounted for by Antarctic melting: 13

SOURCE: Science Express, March 2