NASA mission detects significant Antarctic ice mass loss

Scientists were able to conduct the first-ever gravity survey of the entire Antarctic ice sheet using data from the joint NASA/German Aerospace Center Gravity Recovery and Climate Experiment (GRACE). This comprehensive study found the ice sheet's mass has decreased significantly from 2002 to 2005.

Isabella Velicogna and John Wahr, both from the University of Colorado, Boulder, conducted the study. They demonstrated for the first time that Antarctica's ice sheet lost a significant amount of mass since the launch of GRACE in 2002. The estimated mass loss was enough to raise global sea level about 1.2 millimeters (0.05 inches) during the survey period; about 13 percent of the overall observed sea level rise for the same period. The researchers found Antarctica's ice sheet decreased by 152 (plus or minus 80) cubic kilometers of ice annually between April 2002 and August 2005.

That is about how much water the United States consumes in three months (a cubic kilometer is one trillion liters; approximately 264 billion gallons of water). This represents a change of about 0.4 millimeters (.016 inches) per year to global sea level rise. Most of the mass loss came from the West Antarctic ice sheet.

"Antarctica is Earth's largest reservoir of fresh water," Velicogna said. "The GRACE mission is unique in its ability to measure mass changes directly for entire ice sheets and can determine how Earth's mass distribution changes over time. Because ice sheets are a large source of uncertainties in projections of sea level change, this represents a very important step toward more accurate prediction, and has important societal and economic impacts. As more GRACE data become available, it will become feasible to search for longer-term changes in the rate of Antarctic mass loss," she said.


Source: NASA More here.

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