CRLS98014 sidescan-sonar track lines on the inner continental shelf off the northern Oregon and southern Washington coast from U.S. Geological Survey field activity 1998-014-FA

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Frequently anticipated questions:

What does this data set describe?

CRLS98014 sidescan-sonar track lines on the inner continental shelf off the northern Oregon and southern Washington coast from U.S. Geological Survey field activity 1998-014-FA
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.
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 might this data set be cited?
    Twichell, David C., 2000, CRLS98014 sidescan-sonar track lines on the inner continental shelf off the northern Oregon and southern Washington coast from U.S. Geological Survey field activity 1998-014-FA: Open-File Report 00-167, 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.

    Twichell, David C., Cross, VeeAnn A., and Parolski, Kenneth F., 2000, Sidescan-sonar Imagery, Surface Sediment Samples, and Surficial Geologic Interpretation of the Southwestern Washington Inner Continental Shelf Based on Data Collected During Corliss Cruises 97007 and 98014: Open-File Report 00-167, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -124.500000
    East_Bounding_Coordinate: -123.800000
    North_Bounding_Coordinate: +47.350000
    South_Bounding_Coordinate: +45.900000
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 28-Aug-1998
    Beginning_Time: 14430000Z
    Ending_Date: 16-Sep-1998
    Ending_Time: 18430000Z
    Dates of data acquisition.
  5. What is the general form of this data set?
  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):
      • Complete chain
    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 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
  7. How does the data set describe geographic features?
    ArcView shapefile attribute table (Source: none)
    Line number corresponding to the sidescan-sonar imagery line collected. The numbers are not necessarily sequential. Two types of data were collected on this cruise: sidescan-sonar data and seismic-reflection profiles. These data were not collected concurrently. The line numbers reflect those tracklines along which sidescan-sonar imagery was collected. Apparent gaps are lines in which seismic-reflection profile data was collected. (Source: watch stander on CRLS98014 cruise)
    Range of values

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • David C. Twichell
  2. Who also contributed to the data set?
    Seafloor Mapping Group
  3. To whom should users address questions about the data?
    David C. Twichell
    U.S. Geological Survey
    U.S. Geological Survey
    Woods Hole Field Center
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 (voice)
    508-457-2310 (FAX)

Why was the data set created?

This GIS overlay is a component of the Southwest Washington Coastal Erosion ArcView GIS database. This particular overlay contains the ship tracklines from the Corliss 1998 cruise along which sidescan-sonar data was collected.

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: Sep-1998 (process 1 of 2)
    These tracklines were generated from the navigation merged with the sidescan-sonar data. This navigation was downsampled from the original fix every 10 seconds to a navigational fix every 1 minute. Obviously bad navigation points were removed. Each line segment represents the navigation for the corresponding sidescan-sonar imagery. Each line segment has attribute information indicating which sidescan-sonar line this ship navigation corresponds to. A single sidescan-line can have multiple segments reflecting acquisition interruptions, navigational glitches, or other potential line breaks. Person who carried out this activity:
    VeeAnn A. Cross
    U.S. Geological Survey
    Marine Geologist
    U.S. Geological Survery
    Woods Hole Field Center
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 (voice)
    508-457-2310 (FAX)
    Date: 01-May-2023 (process 2 of 2)
    Edits to the metadata were made to fix any errors that MP v 2.9.50 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). The original metadata was available in HTML only, so had to be reformatted. The citation in the identification section was completely redone, including adding links to the data and larger work citation. Added ISO 19115 Topic Category keywords and USGS Thesaurus keywords. Added keywords section with USGS persistent identifier as theme keyword. The standard order process section in the distribution was modified to include the link to the data. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent. 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)
  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 navigational lines actually represent the ship's position. No instrumentation was available to estimate a range to the sidescan-sonar towfish. However, most of the data were acquired in fairly shallow water, therefore the layback (wire out) was minimal. Assumed accuracy of 10-20 m. This accuracy is dependant on the amount of cable out for the sidescan-sonar towfish - hence tied to water depth.
  2. How accurate are the geographic locations?
    The ship was navigated with P-CODE GPS. No instrumentation was on board to estimate the range to towfish. Therefore these tracklines represent ship's position, not towfish position. However, for the purposes of this study, these tracklines are also used to map the sidescan imagery. Assumed accuracy of 10-20 meters. This is based on the P-CODE GPS having an assumed accuracy of within 10-20 meters.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    These tracklines represent only where sidescan-sonar data were collected. The navigation is sent directly to the sidescan-sonar acquisition computer and merged with the data.
  5. How consistent are the relationships among the observations, including topology?
    The towfish was typically kept 10m above the seafloor as determined from the first sidescan-sonar return. The water depth determined the amount of wire out needed to maintain this fish altitude. Hence, in shallower water, less wire was out and in turn a more accurate representation of fish location as related to the ship's position.

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)
    Nancy Soderberg
    U.S. Geological Survey
    Data Librarian
    U.S. Geological Survey
    Woods Hole Field Center
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 (voice)
    508-457-2313 (FAX)
  2. What's the catalog number I need to order this data set? U.S. Geological Survey CD-ROM Open-File Report
  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 constitute or imply its endorsement, recommendation, or favoring by the United States Government 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?
    • Availability in digital form:
      Data format: shapefile
      Network links:
      Media you can order: CD-ROM (Density 650 MBytes) (format ISO 9600 with Rock Ridge extensions)
      Note: UNIX, DOS, MAC
    • Cost to order the data: none at this time

  5. What hardware or software do I need in order to use the data set?
    These tracklines are available in ArcView shapefile format. The user must have ArcView, Arc Explorer, or another GIS package capable of importing and reading these data.

Who wrote the metadata?

Last modified: 01-May-2023
Metadata author:
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
U.S. Geological Survey
Woods Hole Field Center
384 Woods Hole Rd
Woods Hole, MA

508-548-8700 (voice)
508-457-2310 (FAX)
The metadata contact email address is a generic address in the event the person is no longer with the USGS.
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (19940608)

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Generated by mp version 2.9.51 on Tue May 2 11:09:42 2023