Jaana Gustafson, a geophysicist, prepares her ground penetrating radar equipment for travel by wrapping the wheels with rope for better traction over snow on a glacier near Koge Bay, Greenland, Aug. 1, 2013. Gustafson used the GPR to conduct parallel sweeps over the site where she located a metallic object nearly 40 feet below the surface of the glacier during the 2012 U.S. Coast Guard J2F-4 Grumman Duck aircraft mission. U.S. Coast Guard photo by Petty Officer 2nd Class Jetta H. Disco.