Portion of the 1-meter (m) contours in quadrangle 5 of the Stellwagen Bank Survey Area offshore of Boston, Massachusetts based on bathymetry data collected by the U.S. Geological Survey from 1994-1996

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What does this data set describe?

Title:
Portion of the 1-meter (m) contours in quadrangle 5 of the Stellwagen Bank Survey Area offshore of Boston, Massachusetts based on bathymetry data collected by the U.S. Geological Survey from 1994-1996
Abstract:
The U.S. Geological Survey (USGS), in cooperation with the National Marine Sanctuary Program of the National Oceanic and Atmospheric Administration (NOAA), has conducted seabed mapping and related research in the Stellwagen Bank National Marine Sanctuary (SBNMS) region since 1993. The interpretive datasets and source information presented here are for quadrangle 5, which is one of 18 similarly sized segments of the 3,700 square kilometer (km2) SBNMS region. The seabed of the SBNMS region is a glaciated terrain that is topographically and texturally diverse. Quadrangle 5 includes the shallow, rippled, coarse-grained sandy crest and upper eastern and western flanks of southern Stellwagen Bank, its fine-grained sandy lower western flank, and the muddy seabed in Stellwagen Basin. Water depths range from <25 m on the bank crest to ~100 m in the basin. The data presented here for quadrangle 5 are the foundation for Scientific Investigations Map 3515 (Valentine and Cross, 2024), which presents maps of seabed topography, ruggedness, backscatter intensity, distribution of geologic substrates, sediment mobility, distribution of fine- and coarse-grained sand, and substrate mud content. The maps of quadrangle 5 show the distribution of substrates across the southern part of Stellwagen Bank and the adjacent basins. Bathymetric and seabed backscatter imagery, photographs, video, and grain-size analyses were used to create the geologic interpretations presented here and have been reprocessed and released in segments to supports these interpretations. For the quadrangle 5 interpretations, data from 729 stations were analyzed, including 620 sediment samples. The seabed geology map of quadrangle 5 shows the distribution of 20 substrate types ranging from boulder ridges to mobile and rippled sand, to mud. Substrate types are defined or inferred through sediment grain-size composition, surface morphology, sediment layering, the mobility or immobility of substrate surfaces, and water depth range. Scientific Investigations Map 3515 portrays the major geological elements (substrates, topographic features, processes) of environments within quadrangle 5. It is intended to be a basis for the study of sediment transport processes that affect a shallow, offshore bank, for the study of the ecological requirements of invertebrate and vertebrate species that use these substrates, and to support seabed management in the region.
Supplemental_Information:
Over 50 scientific cruises have been conducted in an in an effort to map Stellwagen Bank. The bathymetry of Quadrangle 5 on Stellwagen Bank is from the following 5 USGS WHCMSC field activities (ship cruises): 1994-008-FA, 1995-013-FA, 1995-033-FA, 1996-032-FA, 1996-043-FA. More information on each of these activities can be found by replacing the XXXX in the following URL with the cruise ID: https://cmgds.marine.usgs.gov/fan_info.php?fan=XXXX. For example: https://cmgds.marine.usgs.gov/fan_info.php?fan=1994-008-FA.
  1. How might this data set be cited?
    Valentine, Page C., 20240320, Portion of the 1-meter (m) contours in quadrangle 5 of the Stellwagen Bank Survey Area offshore of Boston, Massachusetts based on bathymetry data collected by the U.S. Geological Survey from 1994-1996: data release DOI:10.5066/P9W9BN3S, 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., and Cross, VeeAnn A., 2024, Geospatial datasets of seabed topography, sediment mobility, and the distribution of geologic substrates in quadrangle 5 of the Stellwagen Bank National Marine Sanctuary region offshore of Boston, Massachusetts: data release DOI:10.5066/P9W9BN3S, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Valentine, P.C., and Cross, V.A., 2024, Geospatial datasets of seabed topography, sediment mobility, and the distribution of geologic substrates in quadrangle 5 of the Stellwagen Bank National Marine Sanctuary region offshore of Boston, Massachusetts: U.S. Geological Survey data release, https://doi.org/10.5066/P9W9BN3S.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.4111099093
    East_Bounding_Coordinate: -70.2310793442
    North_Bounding_Coordinate: 42.3222681691
    South_Bounding_Coordinate: 42.2028850222
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/63a091a6d34e0de3a1f27738?name=q5_1m_contours_browse.png&allowOpen=true (PNG)
    Thumbnail image of the portion of 1-meter contours used in the interpretation of quadrangle 5 in Stellwagen Bank National Marine Sanctuary.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1994
    Ending_Date: 1996
    Currentness_Reference:
    ground condition of the original bathymetric data acquisition that these contours were derived from
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Vector Digital Dataset (Polyline)
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • String (56)
    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 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_North_American_1983.
      The ellipsoid used is GRS_1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Mean lower low water
      Depth_Resolution: 1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    q5_1m_contours
    Portion of the 1-meter contours that fall within quadrangle 5 of the Stellwagen Bank study area. (Source: U.S. Geological Survey)
    CONTOUR
    These values represent depth. The more negative the value, the deeper the water. Depths are relative to mean lower low water datum. (Source: U.S. Geological Survey)
    Range of values
    Minimum:-81
    Maximum:-26
    Units:meters

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
  2. Who also contributed to the data set?
    Public domain data from the U.S. government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the source of this information.
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: Page C Valentine
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2239 (voice)
    508-457-2310 (FAX)
    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 USGS.

Why was the data set created?

The purpose of this dataset is to release the 1-meter (m) contours that are used in quadrangle 5 Stellwagen Bank geologic interpretation maps that aid in interpretation. The 1-m contours indicate the more hummocky relief of the seabed in areas dominated by gravel deposits and small boulder ridges. The one meter contours accentuate low-relief topographic complexity in these areas. The contours represent a close approximation of seabed microtopography, as the resolution of the multibeam echo sounder data used to generate these data is on the order of 1 m. By contrast, 1-m contours are not shown in areas where the seabed is relatively smooth and not dominated by gravel features. Any topographic complexity in these areas is beyond the resolution of the multibeam echosounder (< 1 meter in relief) and cannot be accurately depicted by the 1-m bathymetric contours.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 1996 (process 1 of 7)
    Initial data collection and processing is described in Valentine and others 1999, Valentine 2005, and Butman and others, 2007. A summary of that information is presented here. Surveying was conducted aboard the Canadian Hydrographic Service vessel Frederick G. Creed using a hull mounted multibeam echo sounder. These data were collected using a Simrad Subsea EM1000 operating at 95 kHz. SwathEd software (version unknown) developed by the Ocean Mapping Group, University of New Brunswick, was used to process the bathymetric and navigation data. The processing included editing the data to remove spurious points as well as incorporating tidal corrections. Processing took place between 1994 and 1996 by a variety of individuals.
    Date: 1997 (process 2 of 7)
    The remaining process steps are a function of incorporating information from the previous publications (noted in cross-references), along with processing notes maintained during data processing. The final SwathEd-produced grid at 10 meters per pixel was converted to an ASCII file using the University of New Brunswick script r4toASCII. The format of the ASCII file is latitude, longitude, and depth. The ASCII file was converted to an ArcInfo ungenerate format using a Perl script. The resulting format is ID, longitude, latitude, and negative depth. Each point has a unique ID value. Using ArcInfo 7.03, the ungenerate format was converted to a coverage format using the 'convert to arc' from 'generate tool' available in ArcTools. The 'build' command with the point option was then used to convert the data to a point coverage. This procedure generates the point locations stored in the ungenerate file but does not incorporate the depth values. To include depth, the ungenerate file - which has location as well as depth - was converted to an ArcInfo table, using 'Tables' in ArcInfo. The structure of the ArcInfo table was defined to include the ID, longitude, latitude, and depth in the appropriate format and size. Longitude and latitude were defined as floating point numbers with six decimal places, while depth was defined as a floating point number with two decimal places. To add the depth value to the point coverage, ArcInfo 'Tables' was used to join the point attribute table (pat) of the coverage to the newly-generated data table based on the ID value. In order to join the tables, the data table ID field had to be renamed to match the automatically assigned coverage ID field. The projection of the point coverage was defined in ArcInfo with the PROJECTDEFINE command and the following parameters: Projection Geographic; Datum NAD83; Units DD; Spheroid GRS80. This process was performed by Jessica Baker in 1997. Then the coverage was projected to the custom Mercator projection using the ArcInfo PROJECT command with the following options: Projection Mercator; Datum NAD83, Spheroid GRS1980; Units Meters; Longitude of Central Meridian -70degrees 19minutes; Latitude of true scale 41degrees 39minutes; False Easting 0; False northing 0. This process was performed by Jessica Baker in 1997. The final step was to convert the points to a grid. This was accomplished using the ArcInfo 'pointgrid' command. The depth attribute was gridded at a cell-size of 13 m, and the background value was set to nodata. This final processing step was performed in 1997, and is the basis for the subsequent work with contours. However, this process was repeated by Tammie Middleton in 2001 and is the grid presented in this data release. The 13-m cell-size was chosen because it reduced stripe artifacts in the data when processing with the SwathEd software.
    Date: 1999 (process 3 of 7)
    The original Mercator grid was projected to a geographic coordinate system using the ArcInfo PROJECT command. Once this was done, the Arc/Info routine lattice contour was used to generate the 1-m contours. Extensive editing was done with ArcEdit to remove contours from areas where the seabed is relatively smooth. Although each quadrangle was contoured independently, the contours were manually edited to remove "boundary faults". All editing work was done by Jessica Baker and Tanya Unger from 1997 to 1999.
    Date: 2013 (process 4 of 7)
    The 1-m coverage file was added to ArcMap 9.3.1. This dataset was then exported to a shapefile. This process step and the subsequent process step were performed by the same person: VeeAnn A. Cross. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 2016 (process 5 of 7)
    Within ArcGIS 10.3.1, attributes associated with the original coverage that were not necessary for the shapefile (such as FNODE, TNODE) were removed.
    Date: 2023 (process 6 of 7)
    Within QGIS 3.16.7-Hannover, contours with a value of 0 were deleted since these are not realistic values within the dataset. Additionally, the Dissolve tool was used to combine the features of a given contour value into a single feature making each contour value a multipart polyline.
    Date: 2023 (process 7 of 7)
    Metadata for the 1-m contours were compiled to publish these data (as part of a USGS data release) in support of a USGS series geologic interpretive report. The information used to pull together the metadata was from previous publications, the extensive data processing log prepared by Tanya Unger and Jessica Baker, as well as the individual log files generated during ArcInfo data processing. Primary work on the metadata was completed in 2016, with later updates.
  3. What similar or related data should the user be aware of?
    Butman, Bradford, Valentine, Page C., Middleton, Tammie J., and Danforth, William W., 2007, A GIS library of multibeam data for Massachusetts Bay and the Stellwagen Bank National Marine Sanctuary, offshore of Boston, Massachusetts: Data Series 99, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication contains additional data and information in Stellwagen Bank National Marine Sanctuary. In particular quadrangles 1, 2, and 3 as well as Massachusetts Bay.
    Valentine, Page C., Baker, Jessica L., Unger, Tanya S., and Polloni, Christopher F., 1998, Sea floor topographic map and perspective-view imagery of quadrangles 1-18, Stellwagen Bank National Marine Sanctuary off Boston, Massachusetts: Open-File Report 98-138, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication contains additional data and information in Stellwagen Bank National Marine Sanctuary. In particular this publication was the source of the 5-meter contours that were used to aid the interpretation presented in the q5_geologic_interp shapefile available from the larger work citation.
    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:
    This publication contains additional data and information in Stellwagen Bank National Marine Sanctuary. This publication contains data from all 18 quadrangles, but in an older format (Arc Export Format).
    Page C. Valentine, editor, 2005, Sea floor image maps showing topography, sun-illuminated topography, backscatter intensity, ruggedness, slope, and the distribution of boulder ridges and bedrock outcrops in the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts: Scientific Investigations Map 2840, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication contains additional data and information in Stellwagen Bank National Marine Sanctuary. In particular this publication contains the sun-illuminated topography raster data, seabed ruggedness raster data, and the combined backscatter intensity/sun-illuminated topography raster data that were used to aid the interpretation presented in the q5_geologic_interp shapefile available from the larger work citation.
    Valentine, Page C., Gallea, Leslie B., Blackwood, Dann S., and Twomey, Erin R., 2010, Seabed photographs, sediment texture analyses, and sun-illuminated sea floor topography in the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts: Data Series 469, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication contains additional data and information in Stellwagen Bank National Marine Sanctuary. In particular this publication contains seabed photographs and sediment texture analyses that were used to aid the interpretation presented in the q5_geologic_interp shapefile available from the larger work citation.
    Valentine, Page C., and Gallea, Leslie B., 2015, Seabed maps showing topography, ruggedness, backscatter intensity, sediment mobility, and the distribution of geologic substrates in quadrangle 6 of the Stellwagen Bank National Marine Sanctuary region offshore of Boston, Massachusetts: Scientific Investigations Map 3341, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication contains the equivalent information as this data release, but for quadrangle 6.
    Valentine, Page C., and Cross, VeeAnn A., 2024, Seabed maps showing topography, ruggedness, backscatter intensity, sediment mobility, and the distribution of geologic substrates in quadrangle 5 of the Stellwagen Bank National Marine Sanctuary region offshore of Boston, Massachusetts: Scientific Investigations Map 3515, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This report is the companion publication of the data release that provides the additional details and information related to the interpretation and methods. Additionally, the report contains PDF map representations of the seabed interpretation. The report also provides additional references related to the work in Stellwagen Bank National Marine Sanctuary.

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?
    Bathymetric data from which these contours were derived were navigated with a differential global positioning system (DGPS) with an assumed accuracy within +/- 10 meters. The contours themselves were digitally derived from the bathymetric data, which could introduce additional horizontal accuracy issues. Total horizontal accuracy is assumed to be within 10 meters.
  3. How accurate are the heights or depths?
    These data have been corrected for vessel motion (roll, pitch, heave, yaw) and tidal offsets, and referenced to mean lower low water. The manufacturer's reported vertical resolution of the Simrad EM-1000 multibeam echo sounder is 1% of water depth, which is less than 2 m given the depths within the study area (~30 to 184 m). Data were corrected for tidal elevation using the NOAA Boston tide gauge. The contours were digitally derived from the bathymetric data.
  4. Where are the gaps in the data? What is missing?
    This dataset only represents a portion of the 1-m contours present in quadrangle 5 of the Stellwagen Bank survey area. Only the contours necessary to show small features are maintained. The 1-m contours call attention to low-relief topographic complexity in areas of hummocky relief dominated by gravel deposits and small boulder ridges. These 1-m contours show seabed microtopography as the bathymetric data approaches the resolution of the multibeam echo sounder that collected the data. Contours have been removed from areas where the seabed is relatively smooth and not dominated by gravel features. In relatively flat areas, 1-m contours produce incoherent patterns that misrepresent topographic complexity of the seabed.
  5. How consistent are the relationships among the observations, including topology?
    These 1-m contours are based on unsmoothed bathymetry terrain, and the contours themselves have not been smoothed or generalized. For this reason, these 1-m contours could possibly intersect or cross 5-m contours (Valentine and others, 1998) of the same area that are based on a filtered topography.

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 Not to be used for navigation.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? The dataset contains the contours as a polyline shapefile (q5_1m_contours.shp and the shapefile components), a browse graphic (q5_1m_contours_browse.png) as well as FGDC CSDGM metadata in XML format.
  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?
  5. What hardware or software do I need in order to use the data set?
    These data are available in Esri shapefile format. The user must software capable of reading this format. The data are available for download in zip format.

Who wrote the metadata?

Dates:
Last modified: 20-Mar-2024
Metadata author:
U.S. Geological Survey
Attn: VeeAnn A. Cross
Marine Geologist
384 Woods Hole Road
Woods Hole, MA

508-548-8700 x2251 (voice)
508-457-2310 (FAX)
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 USGS.
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P9W9BN3S/q5_1m_contours_meta.faq.html>
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