FOR STORY GROENLANDIA-CALENTAMIENTO - FILE - In this July 19, 2011 file photo, attached by rope to a waiting helicopter, Arctic researcher Carl Gladish of New York University hammers a steel stake ... more 
FOR STORY GROENLANDIA-CALENTAMIENTO - FILE - In this July 19, 2011 file photo, attached by rope to a waiting helicopter, Arctic researcher Carl Gladish of New York University hammers a steel stake into ice, securing a newly-deployed GPS seismometer, or Geopebble, designed to track glacial movement near the edge of the Greenland ice sheet, atop Jakobshavn Glacier, outside Ilulissat, Greenland. The chief researcher, NYU's David Holland, hopes to eventually deploy scores of the devices to help measure ice loss in Greenland. (AP Photo/Brennan Linsley, File) less 
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Associated Press | Photo By Brennan Linsley, File
Thu, Sep 1, 2011 10:27 AM EDT