Stratigraphic Framework Maps of the inner-continental shelf within the New York Bight: Pleistocene Thickness Grid

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Frequently-anticipated questions:

What does this data set describe?
    Title:
    Stratigraphic Framework Maps of the inner-continental shelf within the New York Bight: Pleistocene Thickness Grid
    Abstract:
    These data orginate from interpretations of seismic reflection profile data. The derivative data are in a grid format and are intended to represent the thickness and distribution of Pleistocene deposits throughout the inner-continental shelf within the New York Bight. The gridded Pleistocene thickness is helpful in understanding the stratigraphic evolution of the inner-continental shelf, the regional sediment transport system, and the influence of the inner-shelf framework on coastal processes. The grid showing thickness of Pleistocene sediment is an important factor in the framework of the coastal region.

  1. How should this data set be cited?
    Denny, Jane F. , Foster, David S. , Schwab, William C. , and Swift, B. Ann , 20010000, Stratigraphic Framework Maps of the inner-continental shelf within the New York Bight: Pleistocene Thickness Grid: U.S. Geological Survey, Woods Hole, MA.

     

    This is part of the following larger work.
    Schwab, William C., Denny, Jane F., Foster, David S., Lotto, Linda L., Allison, Mead A., Uchupi, Elazar, Swift, B. Ann, Danforth, William W., Thieler, Robert E., and Butman, Bradford, 2002, High-Resolution Quaternary seismic stratigraphy of the New York Bight Continental Shelf: Open-File Report OFR02-152, U.S. Geological Survey, Woods Hole, MA.

     

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -74.06
    East_Bounding_Coordinate: -71.8000
    North_Bounding_Coordinate: 41.2322
    South_Bounding_Coordinate: 40.15
  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 01-May-1995
    Ending_Date: 01-Nov-1998
    Currentness_Reference: ground condition
  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: map
  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Raster data set. It contains the following raster data types:

      • Dimensions 485 x 649, type Grid Cell
    2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 18
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -075.000000
      Latitude_of_Projection_Origin: +00.000000
      False_Easting: 500000
      False_Northing: 0

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 200
      Ordinates (y-coordinates) are specified to the nearest 200
      Planar coordinates are specified in Meters

      The horizontal datum used is WGS84.
      The ellipsoid used is WGS84.
      The semi-major axis of the ellipsoid used is 6378137.0000000.
      The flattening of the ellipsoid used is 1/298.26.

      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Vertical Datum of 1988
      Altitude_Resolution: 1
      Altitude_Distance_Units: Meters
      Altitude_Encoding_Method:
      Explicit elevation coordinate included with horizontal coordinates
      Depth_System_Definition:
      Depth_Datum_Name: Mean sea level
      Depth_Resolution: 0.1
      Depth_Distance_Units: Meters
      Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?
    This data set resulted from a cooperative with the US Geological Survey and the US Army Corps of Engineers.
  3. To whom should users address questions about the data?
    US Geological Survey
    c/o Jane F. Denny
    Geologist, Seafloor Mapping Group
    384 Woods Hole Road
    Woods Hole, MA 012543
    USA

    508-457-2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

Why was the data set created?
In 1995, the U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (USACE), began a program to generate reconnaissance maps of the sea floor offshore of the New York - New Jersey metropolitan area and within the southern Long Island nearshoe area. Our methods include high-resolution sidescan sonar and subbottom profiling techniques, along with surface grab and vibracore sampling to verify the geophysical interpretations. The goal of the investigation is to provide a regional synthesis of the sea-floor environment, to determine regional-scale availability of sand as a resource for beach nourishment programs, and to investigate the role that inner-shelf morphology and geologic framework have in the evolution of the coastal region within the New York Bight Apex and southern Long Island. Maps derived from interpretation of the subbottom profiles show information on the geometry and distribution of the Quaternary sediments and the underlying coastal-plain unconformity. This seismic stratigraphy yields a regional framework on which explanations of present (and past) sediment movement, dispersal, and erosion processes are based.

How was the data set created?
  1. From what previous works were the data drawn?

    Holocene and Quaternary Isopachs (source 1 of 1)
    Denny, Jane F. , 2002 , High-Resolution Quaternary seismic stratigraphy of the New York Bight continental shelf: Open-File Report 02-152, US Geological Survey, Woods Hole, MA.

    Online Links:

    Type_of_Source_Media: digital raster data
    Source_Contribution:
    The Quaternary and Holocene Isopach (gridded data) were used to generate the Pleistocene Isopach. Pleistocene thickness was represented by the difference between the Quaternary and Holocene sediment thickness.

  2. How were the data generated, processed, and modified?

    Date: 2002 (process 1 of 5)
    The difference between the Quaternary and Holocene Isopachs was used to generate the Pleistocene Isopach within Dynamic Graphics Inc., EarthVision surface modelling software. The resultant grid has a grid cell size of 100, yeilding a grid size of 1007 rows and 1854 columns. The grid was exported as an ASCII raster format file.

    Person who carried out this activity:

    Jane F. Denny
    US Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

    508-457-2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

    Date: 1998 (process 2 of 5)
    The exported ASCII Pleistocene thickness grid file from EarthVision was edited to create an ASCII grid file suitable for import to ArcView software. The order of rows were flipped, so that the file begins with the lower row, left column and ends with the upper row right column. An ArcView header that descibes the lower left origin of the grid, the grid cell size, the number of rows and columns, and the null value used (-9999).

    Person who carried out this activity:

    Jane F. Denny
    US Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

    508-457-2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

    Data sources used in this process:
    • sandiso

    Date: 1998 (process 3 of 5)
    The edited ASCII grid file was imported into ArcView software with the 3D Spatial Analyst extension. The file was saved as a Spatial Analyst (ArcInfo raster grid format) grid.

    Person who carried out this activity:

    David S. Foster
    US Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

    508-457-2271 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

    Data sources used in this process:
    • sandiso

    Date: 2000 (process 4 of 5)
    Contour data were generated from the Pleistocene Isopach Gridded data at a 5 meter contour interval within EarthVision. These data were exported and converted to an ESRI generate format. The contour interval associated with each contour was saved as an ASCII file and read into ArcView in table format. The generate file was converted to a vector shapefile. The table and attritube table of the contour shapefile were joined based on unique contour IDs. The attribute table was then editted to include the associated contour value with each contour line, and the join was removed. These contour data are stored in the Geographic Coordinate System (decimal degrees, WGSir Ellipsoid).

    Person who carried out this activity:

    Jane F. Denny
    US Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

    508-457-2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

    Date: 2000 (process 5 of 5)
    The grid and contour data were clipped, using GRIDCLIP script within ArcView 3.2, to the extents of the 1995 and 1996 survey areas.

    Person who carried out this activity:

    Jane F. Denny
    US Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

    508-457-2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?

    These data are derived from grids generated from interpretation of 2D seismic reflection profiles. The horizontal resolution of the gridded data are constrained by the grid cell size of 100 meters. Horizontal interpolation is inherent in the gridding process.

  2. How accurate are the geographic locations?

    DGPS is assumed to be accurate within 1-2 meters. Standard GPS is assumed accurate within 5-10 meters. 99% of the positional data is DGPS. Unless noted, all GPS/DGPS data is referenced to WGS84 (NAD83). Tow fish (sidescan) position was corrected for layback using acoustic slant range measurements and fish pressure depth measurements, otherwise corrected for layback by manual inputs for slant range and fish depth. Accuracy for slant range varies with distance from the ship and the noise conditions in the water, nominally up to 30 meters is better than 2 meters. Pressure depth is accurate to .1 meter. Manual slant range can use cable out measurements or estimates based on data processing results.

  3. How accurate are the heights or depths?

    Vertical positioning is not necessary to quantify thickness of sediment data. The data are referenced to the distance between the sea floor and the base of the modern sand using an acoustic velocity of 1630 m/s.

  4. Where are the gaps in the data? What is missing?

    The gridded data are limited by horizontal resolution of the grid cell size and spatial distribution of the original point data used to generate the two reference grids: Holocene and Quaternary Isopach. Higher resolution data acquisition will likely result in a more detailed representation of sediment distribution and thickness. The data also represent a time interval of the data acquisition. Attributes may and probably do change with time.

  5. How consistent are the relationships among the observations, including topology?

    The gridded data were checked for consistency by plotting the Holocene and Quaternary Isopach to ensure that the grid values represent accurate Pleistocene thicknesses, given the aforementioned Isopachs as reference.

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)
    Jane F. Denny
    US Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

    508-457-2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

  2. What's the catalog number I need to order this data set?

    piso

  3. What legal disclaimers am I supposed to read?
    Altough this data set and its lineage have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and/or it's related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related items. Users must assume responsibility for the proper use of this data. This data should not be used at resolutions for which it is not intended. This data has no been reviewed for conformity with US Geological Survey editorial standards, or the North American Strigraphic code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the US Government.
  4. How can I download or order the data?

Who wrote the metadata?
Dates:
Last modified: 19-Jan-2002
Last Reviewed: 2002

Metadata author:
Jane F. Denny
US Geological Survey
Geologist
384 Woods Hole Road
Woods Hole, MA 02543
USA

508-457-2311 (voice)
508-457-2310 (FAX)
jdenny@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial (FGDC-STD-001-1998)

Generated by mp version 2.7.17 on Fri Apr 12 09:15:08 2002