Iceberg scours on the seafloor

These 3D perspective views of the seafloor bathymetry from multibeam sonar offshore of South Carolina show numerous grooves carved by drifting icebergs. As iceberg keels plow into the seafloor, they dig deep grooves that push aside boulders and piles of sand and mud along their tracks. Sediment cores from nearby buried iceberg scours were used to determine when these icebergs travelled south along the coast. Credit: Jenna Hill, U.S. Geological Survey, Pacific Coastal and Marine Science Center