Over the past ten years scientists have measured increasing ice loss along southern Greenland. Now a new study in Geophysical Research Letters shows that the ice loss has spread north with likely consequences for global sea level rise.
Collecting data from NASA’s satellite Gravity and Recovery Climate Experiment, known as GRACE, and GPS measurements of the bedrock on the edges of the ice sheet, the Denmark Technical Institute’s National Space Institute in Copenhagen was able to show that crustal uplift due to ice loss has gone up by 1.5 inches between October 2005 and August 2009 along the northwest coast, a change that study co-author John Wahr calls “very dramatic”.
“This is a phenomenon that was undocumented before this study,” added Wahr, a physics professor at the Colorado University-Boulder, which participated in the study. “Our speculation is that some of the big glaciers in this region are sliding downhill faster and dumping more ice in the ocean.”
Already, ice loss in Greenland is contributing to global sea level rise. A study last year showed that between April 2002 and February 2009 the Greenland ice sheet lost 385 cubic miles of ice, adding approximately 0.5 millimeters of sea-level rise every year.
“These changes on the Greenland ice sheet are happening fast, and we are definitely losing more ice mass than we had anticipated,” said Isabella Velicogna, lead author of the study last year. “We also are seeing this ice mass loss trend in Antarctica, a sign that warming temperatures really are having an effect on ice in Earth’s cold regions.”
The northern melting will likely add to sea level rise explains lead author, Shfaqat Abbas Khan: “If this activity in northwest Greenland continues and really accelerates some of the major glaciers in the area—like the Humboldt Glacier and the Peterman Glacier—Greenland’s total ice loss could easily be increased by an additional 50 to 100 cubic kilometers (12 to 24 cubic miles) within a few years.”
Citation: Khan, S. A., J. Wahr, M. Bevis, I. Velicogna, and E. Kendrick (2010), Spread of ice mass loss into northwest Greenland observed by GRACE and GPS, Geophys. Res. Lett., 37, L06501, doi:10.1029/2010GL042460.
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