Grid Representing the Sediment Thickness Between the Lowstand and Ravinement Surfaces

Frequently-anticipated questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
• 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?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

Title:

Grid Representing the Sediment Thickness Between the Lowstand and Ravinement 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. , 20011000, Grid Representing the Sediment Thickness Between the Lowstand and Ravinement Surfaces: U.S. Geological Survey, Woods Hole, MA.

   This is part of the following larger work.

   Twichell, David C. , and Cross, VeeAnn A. , 200110000, 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: -124.869822

   East_Bounding_Coordinate: -123.756691

   North_Bounding_Coordinate: 47.348984

   South_Bounding_Coordinate: 45.925996

3. What does it look like?

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

   Calendar_Date: Oct-2001

   Currentness_Reference: publication date

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

   Geospatial_Data_Presentation_Form: raster digital data

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 784 x 413 x 1, 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: 10

      Transverse_Mercator:

      Scale_Factor_at_Central_Meridian: 0.999600

      Longitude_of_Central_Meridian: -123.000000

      Latitude_of_Projection_Origin: 0.000000

      False_Easting: 500000.000000

      False_Northing: 0.000000

      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 200.000000
      Ordinates (y-coordinates) are specified to the nearest 200.000000
      Planar coordinates are specified in meters

      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?

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
   • VeeAnn A. Cross

2. Who also contributed to the data set?

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

   David C. Twichell
   U.S. Geological Survey
   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?

This GIS overlay is a component of the Southwest Washington Coastal Erosion ArcView GIS database. This grid coverage represents the thickness of sediment deposited between the lowstand and ravinement surfaces.

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: 2001 (process 1 of 1)

   The spatial analyst raster calculator of ESRI's ArcMap was used to calculate this surface by simply subtracting the lowstand surface from the ravinement surface. The units on the cell values is meters.

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?

   Consistent.

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
   U.S. Geological Survey
   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?
   • Availability in digital form:

     Data format:	ARCG Size: 1.547
     Media you can order:	CD-ROM (Density 650 MBytes) (format ISO9660 with Rock Ridge Extensions) Note: UNIX, PC, 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?

   Able to read ESRI grid format.

Who wrote the metadata?

Dates:

Last modified: 15-Aug-2001

Metadata author:

VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
384 Woods Hole Rd.
Woods Hole, MA 02543

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:

• URL: http://www.esri.com/metadata/esriprof80.html

Generated by mp (URL: http://geology.usgs.gov/tools/metadata/tools/doc/mp.html ) version 2.7.3 on Fri Nov 16 16:31:52 2001