AFSC/RACE/GAP/Zimmermann: Aleutians Sediments

We assembled 2.1 million National Ocean Service (NOS) bathymetric soundings extending 1,900 km along the Aleutian Islands from Unimak Island in the east to the Russian border in the west, and ranging approximately 500 km north of the central Aleutians to Petrel and Bowers Banks, and also the surrounding deep waters of the southeastern Bering Sea. These bathymetry data are available from the National Geophysical Data Center (NGDC: http://www.ngdc.noaa.gov), which archives and distributes data that were originally collected by the NOS and others. While various bathymetry data have been downloaded previously from NGDC, compiled, and used for a variety of projects, our effort differed in that we compared and corrected the digital bathymetry by studying the original analog source documents - digital versions of the original survey maps, called smooth sheets. Our editing included deleting erroneous and superseded values, digitizing missing values, and properly aligning all data sets to a common, modern datum. We also digitized 25,000 verbal surficial sediment descriptions from the smooth sheets, providing the largest single source of sediment information for the Aleutians.