Polygon Bounds Necessary to Calculate 1000 year Surfaces

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Frequently-anticipated questions:

What does this data set describe?

    Title: Polygon Bounds Necessary to Calculate 1000 year Surfaces
    Abstract:
    Two 21-day field operations were conducted in 1997 and 1998 in the estuaries and on the inner continental shelf off the northern Oregon and southern Washington coast. These cruises aboard the R/V Corliss were run in order to generate reconnaissance maps of the seafloor geology and the shallow subsurface stratigraphy using sidescan sonar and seismic-reflection mapping techniques. The 1998 cruise also collected sediment grab samples, bottom photographs, and video images to verify the sidescan-sonar imagery and to document the seafloor geology. The combination of these data with previously collected sediment sample data (Robert, 1974; Nittrouer, 1978; and Smith et. al., 1980) has been used to define the extent and lithology of shelf sediments associated with the Columbia River littoral cell. This work is one component of a larger project studying the erosion of the Washington and Oregon coast and is being coordinated by the U.S. Geological Survey and the Washington State Department of Ecology. The reason for collecting these data is to provide a regional synthesis of the offshore geology to support a wide variety of management decisions and to provide a basis for further process-oriented investigations.
    Supplemental_Information:
    Roberts, R.W., 1974, Marine sedimentological data of the Washington continental shelf: University of Washington, Department of Oceanography Special Report 57, 129p.

    Nittrouer, C.A., 1978, The process of detrital sediment accumulation in a continental shelf environment: an examination of the Washington shelf: PhD Thesis, University of Washington, Seattle, WA. 243p.

    Smith, J.M., Messmer, L.W., Phipps, J.B., Samuelson, D.F., and Schermer, E.D., 1980, Grays Harbor and Chehalis River improvements to navigation environmental studies - Grays Harbor ocean disposal study: literature review and preliminary benthic sampling: U.S. Army Corps of Engineers Internal Report.

  1. How should this data set be cited?

    Twichell, David C. , and Cross, VeeAnn A. , 20010716, Polygon Bounds Necessary to Calculate 1000 year Surfaces: U.S. Geological Survey, Woods Hole, MA.

    Online Links:

    • \\REDHOOK\OFR_01_76\shapefiles\conbndsgeog\c11tybpg.shp

    This is part of the following larger work.

    Twichell, David C. , and Cross, VeeAnn A. , 20011000, Holocene Evolution of the Southern Washington and Northern Oregon Shelf and Coast: Geologic Discussion and GIS Data Release: U.S. Geological Survey Open-File Report Report 01-076.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -124.861803
    East_Bounding_Coordinate: -123.760722
    North_Bounding_Coordinate: 47.343398
    South_Bounding_Coordinate: 45.931370

  3. What does it look like?

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

    Calendar_Date: 16-Jul-2001
    Currentness_Reference: publication date

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: vector digital data

  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):

      • G-polygon (3)

    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 0.00018. Longitudes are given to the nearest 0.00026. Latitude and longitude values are specified in Decimal degrees.

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.

  7. How does the data set describe geographic features?

    c11tybpg.dbf
    ArcView shapefile attribute table (Source: ESRI)

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    DEPOSITION
    Type of sediment found in this polygon during this time frame. (Source: Scientist.)

    character set.

    AREA_M_
    Area of the polygon in meters. (Source: Computer calculated.)

    Range of values
    Minimum:1620335
    Maximum:6651068416
    Units:meters

    PERIM_M_
    Perimeter of the polygon in meters. (Source: Computer calculated.)

    Range of values
    Minimum:7045
    Maximum:669144
    Units:meters

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?

  3. To whom should users address questions about the data?

    David C. Twichell
    USGS
    Oceanographer
    384 Woods Hole Rd.
    Woods Hole, MA 02543
    USA

    508-548-8700 (voice)
    508-457-2310 (FAX)
    dtwichell@usgs.gov

Why was the data set created?

These GIS overlays are a component of the Southwest Washington Coastal Erosion ArcView GIS database. These polygon shapefiles represent the boundary information for the surface calculations at 1000 year intervals.

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: 01-Mar-2001 (process 1 of 1)
    Each polygon represents the bounds of the study area, as well as polygons descerning between shelf, bay, and/or beach deposits. These depositional polygons are a result of taking a contour from the ravinement surface based on the sea level curve at that time. The boundary between shelf and bay from 5000 to the present, as well as the beach polygons had a great deal of scientist intervention. Once the initial polygons were set in ArcView, they were then converted to Arc/Info coverages, cleaned up to remove sliver polygons. These coverages were then converted back to ArcView shapefiles and converted to the geographic coordinate system using the sample extension !Projector that comes with ArcView. A much more detailed description of all the processing steps is contained in the USGS Open-file report 01-076 "Holocene Evolution of the Southern Washington and Northern Oregon Shelf and Coast: Geologic Discussion and GIS Data Release" by David C. Twichell and VeeAnn A. Cross.

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. How accurate are the heights or depths?

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

    This data is complete for this particular study.

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

    Consisten.

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:
The U.S. Geological Survey must be referenced as the originator of the dataset in any future products or research derived from these data.

  1. Who distributes the data set? (Distributor 1 of 1)

    David C. Twichell
    USGS
    Oceanographer
    384 Woods Hole Rd.
    Woods Hole, MA 02543
    USA

    508-548-8700 (voice)
    508-457-2310 (FAX)
    dtwichell@usgs.gov

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

  3. What legal disclaimers am I supposed to read?

    This Compact Disc-Read Only Memory (CD-ROM) publication was 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 in this report, 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 constitude or imply its endorsement, recommendation, or favoring by the United States Governemnt or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data published on this CD-ROM have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials.

  4. How can I download or order the data?

  5. What hardware or software do I need in order to use the data set?

    Able to read or translate ArcView shapefile format.

Who wrote the metadata?

Dates:
Last modified: 10-Aug-2001

Metadata author:
VeeAnn A. Cross
USGS
Marine Geologist
384 Woods Hole Rd.
Woods Hole, MA 02543
USA

508-548-8700 (voice)
508-457-2310 (FAX)
vatnipp@usgs.gov

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

Metadata extensions used:

Generated by mp (URL: http://geology.usgs.gov/tools/metadata/tools/doc/mp.html ) version 2.7.3 on Fri Nov 16 16:29:15 2001