Glaciers Melting Faster In West Antarctica Now Than 40 Years Ago: Study
When scientists recently explored the icy edges of Western Antarctica using 40 years of satellite data, they discovered the rate of glacial loss has been rapidly accelerating. Massive sheets of ice are breaking off the fraying edges of the continent in six locations at a rate 77 percent faster than in 1973, they reported in a study out this month.
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This loss of ice, they said, "has a significant impact on sea level rise" and, if melted completely, these six glaciers alone would hoist the oceans four feet higher. "This region is considered the potential leak point for Antarctica because of the low seabed. The only thing holding it in is the ice shelf," NASA geologist Robert Thomas said in a statement. He was not involved with the study, published recently in Geophysical Research Letters.
A tenth of sea level rise can be traced to six glaciers roughly directly south of the United States, which has made it an attractive subject for observation. In 2012, a team from the University of Texas at Austin completed a similar study, looking at West Antarctic glaciers over a 40-year period. They found that the floating glaciers are tearing away from their rocky holds upstream.
"Anyone can examine this region in Google Earth and see a snapshot of the same satellite data we used," lead author Joseph MacGregor said at the time. Calving is the term for when a chunk of ice breaks apart from the glacier. "But only through examination of the whole satellite record is it possible to distinguish long-term change from cyclical calving,"
Pine Island Glacier (click here to see this glacier on Google Earth) is the most active of the six in the present study, and it was releasing 69 percent more ice into the ocean in 2013 than it was in 1973. The Thwaites, Haynes, Smith, Pope, and Kohler glaciers all had also accelerated at varying rates, often in fits and starts. "Half of the increase [in all six] occurred between 2003 and 2009," wrote the authors of the study, all geologists at the University of California, Irvine.
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