Stellwagen Bank bathymetry - Percent slope derived from 5-meter bathymetric contour lines

Percent slope of Stellwagen Bank bathymetry. Raster derived from 5-meter bathymetric contour lines (Quads 1-18). Collected on surveys carried out in 4 cruises 1994 - 1996 using the Kongsberg SIMRAD EM1000 multibeam system on the CHS vessel Frederick G. Creed. For each quad, multibeam data was processed, converted to an ARC/INFO point coverage, gridded with a cell-size of 13m and contoured at an interval of 5m. 18 quads were merged into one shapefile for convenience in this publication. Scale 1:25,000

DATA ACQUISITION:5-meter bathymetric contour lines for Stellwagen Bank (Quads 1-18). Collected on surveys carried out in 4 cruises 1994 - 1996 using the Kongsberg SIMRAD EM1000 multibeam system on the CHS vessel Frederick G. Creed. For each quad, multibeam data was processed, converted to an ARC/INFO point coverage, gridded with a cell-size of 13m and contoured at an interval of 5m. 18 quads were merged into one shapefile for convenience in this publication. Ground truthing of the image data was done with the use of a Sea Bed Observation and Sampling System (SEABOSS) designed by USGS. The SEABOSS contains two video cameras, a still camera, a pressure-depth sensor, and a modified Van Veen sediment grab sampler. This allows for rapid and effective collection of seabed images and sediment samples. DATA PROCESSING:The depth information from the topographic imagery was brought into Arc/Info, where it was gridded and contoured. The gridding was done at a 13 meters/pixel cell size resolution, and the contours were generated at 5 meter intervals.The sample, video, and photo information collected by the SEABOSS were transferred into a GIS database along with the multibeam imagery. The database now contains 8 thematic layers, including: sun-illuminated imagery, acoustic backscatter imagery, sea-floor feature polygons, 1-and 5-meter contours, videography tracklines, still photos, sediment sample information, and sediment classification polygons. Each of these layers was utilized within the GIS to provide a comprehensive analysis of the SBNMS region.Detailed digital maps are being compiled from this database, using GIS to overlay and analyze the different themes. Map layouts are created in Arc/Info and transferred into a drawing program for printed output. The published maps and digital database are now being distributed on web pages or CD-ROMs for use by scientists, managers, and the general public.In addition to these published products, three dimensional perspective views and fly-overs are being created from the multibeam imagery. These types of output provide additional visualization capabilities for the region. The digital database is now easily updateable and can be used along with navigation software to aid in additional data collection while at sea.

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USGS Marine GIS Library for Massachusetts Bay (Ch. 3, file name: bathy5sb.shp)

Shapefile containing raster digital data. For each quad, multibeam data was processed, converted to an ARC/INFO point coverage, gridded with a cell-size of 13m and contoured at an interval of 5m. 18 quads were merged into one shapefile for convenience in this publication. Scale 1:25,000

Valentine, P., J. Baker, T. Unger, C. Polloni, 1998, Sea Floor Topographic Map and Perspective-View Imagery of Quadrangles 1-18, Stellwagen Bank National Marine Sanctuary off Boston, Massachusetts, USGS Open-File Report 98-138.

These data were prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data have been used by NOAA, no warranty, expressed or implied, is made by NOAA as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by NOAA in the use of these data or related materials.NOAA makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA can not assume liability for and damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system.

Please contact the Stellwagen Banks NMS Research Coordinator for additional information on data access (david.wiley@noaa.gov);

Contact USGS: http://pubs.usgs.gov/of/1999/of99-439/

Contact USGS: http://pubs.usgs.gov/of/1999/of99-439/

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