Sun-illuminated Sea Floor Topographic Maps and Perspective View Imagery; Quadrangle 11

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Frequently anticipated questions:

What does this data set describe?

Title:
Sun-illuminated Sea Floor Topographic Maps and Perspective View Imagery; Quadrangle 11
Abstract:
This data set contains the topographic contours and sun-illuminated imagery of Quadrangle 11. This coverage is one in a series of 18 quadrangles in the Stellwagen Bank National Marine Sanctuary region. The project is designed to provide detailed maps of the Stellwagen Bank region's environments and habitats and the first complete multibeam bathymetric and sea floor characterization maps of a significant region of the shallow EEZ.
  1. How might this data set be cited?
    Valentine, Page C., Unger, Tanya S., Baker, Jessica L., and Polloni, Chris, 1999, Sun-illuminated Sea Floor Topographic Maps and Perspective View Imagery; Quadrangle 11: Open-File Report 99-363, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Valentine, Page C., Unger, Tanya S., Baker, Jessica L., and Polloni, Christopher F., 1999, Sun-illuminated sea floor topographic maps and perspective-view imagery of quadrangles 1-18, Stellwagen Bank National Marine Sanctuary off Boston, Massachusetts: Open-File Report 99-363, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    The full title is Sun-illuminated sea floor topographic maps and perspective view imagery of Quadrangles 1-18, Stellwagen Bank National Marine Sanctuary off Boston, Massachusetts.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.41157029
    East_Bounding_Coordinate: -70.22224961
    North_Bounding_Coordinate: 42.56120772
    South_Bounding_Coordinate: 42.44153548
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 15-Aug-1994
    Ending_Date: 22-Sep-1998
    Currentness_Reference:
    Multibeam data were collected from the years of 1994 to 1996. Contours and imagery were generated and edited through 1998.
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: maps, raster digital data, vector data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest .00003. Longitudes are given to the nearest .00003. Latitude and longitude values are specified in Decimal Degrees. The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is GRS1980.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Local surface
      Depth_Resolution: 1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview: Raw Simrad EM 1000 echo sounder data.
    Entity_and_Attribute_Detail_Citation: Simrad Subsea A/S, Horten, Norway

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Page C. Valentine
    • Tanya S. Unger
    • Jessica L. Baker
    • Chris Polloni
  2. Who also contributed to the data set?
    U.S. Geological Survey, National Oceanic and Atmospheric Administration, Canadian Hydrographic Service, University of New Brunswick
  3. To whom should users address questions about the data?

Why was the data set created?

Development of a GIS database of sea floor imagery that is accessible to scientists, policymakers, managers, and the general public. Data were collected on four cruises over a two year period from the fall of 1994 to the fall of 1996. The surveys were conducted aboard the Canadian Hydrographic Service vessel Frederick G. Creed, a SWATH (Small Waterplane Twin Hull) ship that surveys at speeds of 16 knots. The multibeam data were collected utilizing a Simrad Subsea EM 1000 Multibeam Echo Sounder (95 kHz) that is permanently installed in the hull of the Creed.

How was the data set created?

  1. From what previous works were the data drawn?
    USGS (source 1 of 1)
    Simrad EM1000 Frederick K Creed, Unpublished material, information not available from original metadata - but assumption is that it refers to the original collected multibeam data.

    Type_of_Source_Media: digital UNIX tar files on CD-ROM
    Source_Scale_Denominator: 25000
    Source_Contribution:
    information not available from original metadata - but assumption is that it refers to the original collected multibeam data
  2. How were the data generated, processed, and modified?
    Date: Unknown (process 1 of 2)
    Multibeam data were processed using SwathEd, a suite of multibeam software editing and display tools developed by Dr. John Hughes Clarke of the Ocean Mapping Group, University of New Brunswick (UNB). The navigation and topographic data were both edited using this software. Tidal corrections were obtained from NOAA's Boston Tide Gauge (Station 8443970) and merged into the data set using UNB's tidal routines. The topographic information was converted into an ascii textfile containing lat, long, and depth fields, using a script created by Bill Danforth at the U.S. Geological Survey. The ascii file was brought into Arc/Info, and a grid was generated and processed using ESRIs Arc/Info version 7.0.4 software. A point coverage containing depth values was created using the routine point-generate. The grid was created based on the depth values for each of the points using the command pointgrid. The grid was filtered with a 9 by 9 focalmedian filter. Contours were generated using latticecontour. All editing and edgematching was done by hand using arcedit. The shaded relief images shown here were created using a light source that is 45 degrees above the horizon from an azimuth of 350 degrees. The vertical exaggeration in the images is four times. In effect, topographic relief is enhanced by illuminating the sea floor from a position 10 degrees west of north so that shadows are cast on the southern flanks of seabed features. Some features in the images are artifacts of data collection. They are especially noticeable where the seabed is smooth and include small highs and lows and unnatural-looking features and patterns that are oriented parallel or perpendicular to survey tracklines. For a depiction of the topographic contours alone, and for an explanation of survey and topographic data processing methods, see the companion maps by Valentine and others (1997a-r). Topographic contour maps of all 18 quadrangles of the map series are available on a CD-ROM in EPS, PS, Arc export, and PDF file formats (Valentine and others, 1998). Blank areas represent places where no data exists. Person who carried out this activity:
    William Danforth
    USGS, Coastal and Marine Geology
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-457-2274 (voice)
    508-457-2310 (FAX)
    bdanforth@usgs.gov
    Date: 09-Sep-2025 (process 2 of 2)
    This metadata file was edited for inclusion in the CMHRP metadata inventory. These edits included but are not limited to: Added additional information to the citation and larger work citation including the series information and online links as well as fixing other elements; added additional geospatial presentation forms; removed elements for time (publication time, beginning time etc); added the ISO 19115 Topic Category theme keywords; added USGS Thesaurus theme keywords; flushed out the information in the cross-references including adding online links; flushed out information in the source contribution based on some assumptions from knowledge of the work; removed blank elements that aren’t required; updated the distribution liability with an FSP approved statement; added the different formats of the available data as well as links to download the various files; added technical prerequisites explaining that the CD-ROM distribution, although available for all the formats, was only specified on the first digital format; updated the metadata date; provided a generic email and contact instructions in the metadata contact section, but did not edit the contact person. Compare the metadata dates to determine which metadata file is most recent in the event more than one metadata is discovered. A persistent identifier (PID) was added to the metadata in the thesaurus section. (20250909) Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?
    Valentine, Page C., Unger, Tanya S., and Baker, Jessica L., 2000, Sun-illuminated sea floor topography of Quadrangle 11 in the Stellwagen Bank National Marine Sanctuary off Boston, Massachusetts: IMAP 2711, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    The publication of this cross-reference was likely in the final stages of being released when the series report publication this metadata record describes was released, hence the apparent discrepancy in the publication dates. The original publication date in the metadata for this cross-reference was 1999, but the USGS publication site indicates a 2000 publication date.
    Valentine, Page C., Baker, Jessica L., Unger, Tanya S., and Roworth, Edwin T., 1997, Sea Floor Topography of Quadrangle 11 in the Stellwagen Bank National Marine Sanctuary off Boston, Massachusetts: Open-File Report 97-684, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details: scale 1:25,000, 1 sheet

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
    +-3 meters
  3. How accurate are the heights or depths?
    +-3 meters
  4. Where are the gaps in the data? What is missing?
    None
  5. How consistent are the relationships among the observations, including topology?
    None

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints None
Use_Constraints None.
  1. Who distributes the data set? (Distributor 1 of 1)
    USGS, Woods Hole Field Center
    Attn: Page Valentine
    384 Woods Hole Road
    Woods Hole, MA
    USA

    (508) 457-2239 (voice)
    (508) 457-2310 (FAX)
    pvalentine@usgs.gov,
  2. What's the catalog number I need to order this data set? Data are available in a number of formats. The map is available in Encapsulated Postscript (EPS, Postscript(ps), Portable Document File (PDF). The sun-illuminated bathymetry image appropriate for a GIS is available in TIFF image format with an accompany TIFF world file. The 5-m contours are available in Arc/Info Export Format (E00).
  3. What legal disclaimers am I supposed to read?
    Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 09-Sep-2025
Metadata author:
USGS Woods Hole Field Center 384 Woods Hole Road Woods Hole, MA 02543-1598
Attn: William Danforth
384 Woods Hole Road
Woods Hole, MA
USA

(508) 457-2274 (voice)
whsc_data_contact@usgs.gov
Contact_Instructions:
The metadata contact email address is a generic address in the event the person is no longer with the U.S. Geological Survey.
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/open_file_report/ofr1999-363/area11_meta.faq.html>
Generated by mp version 2.9.51 on Tue Sep 9 10:23:08 2025