Bed-sediment grain-size and morphologic data from Suisun, Grizzly, and Honker Bays, CA 1998-2002

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Frequently-anticipated questions:

What does this data set describe?

Title:
Bed-sediment grain-size and morphologic data from Suisun, Grizzly, and Honker Bays, CA 1998-2002
Abstract:
"The USGS Place Based Studies Program for San Francisco Bay investigates this sensitive estuarine system to aid in resource management. As part of the inter-disciplinary research program, the USGS collected side-scan sonar data and bed-sediment samples from north San Francisco Bay to characterize bed-sediment texture and investigate temporal trends in sedimentation. The study area is located in central California and consists of Suisun Bay, and Grizzly and Honker Bays, sub-embayments of Suisun Bay. During the study (1998-2002), the USGS collected three side-scan sonar data sets and approximately 300 sediment samples. The side-scan data revealed predominantly fine-grained material on the bay floor. We also mapped five different bottom types from the data set, categorized as featureless, furrows, sand waves, machine-made, and miscellaneous. We performed detailed grain-size and statistical analyses on the sediment samples. Overall, we found that grain size ranged from clay to fine sand, with the coarsest material in the channels and finer material located in the shallow bays. Grain-size analyses revealed high spatial variability in size distributions in the channel areas. In contrast, the shallow regions exhibited low spatial variability and consistent sediment size over time."
Supplemental_Information:
Specific cruise identifications with links to metadata provided by the USGS Coastal and Marine Geology team's Infobank are given in table 1 of the report. Data included in usSEABED (<http://walrus.wr.usgs.gov/usseabed>)
  1. How should this data set be cited?

    Hampton, Margaret A. , Snyder, Noah P. , Chin, John L. , Allison, Dan W. , and Rubin, David M. , 2003, Bed-sediment grain-size and morphologic data from Suisun, Grizzly, and Honker Bays, CA 1998-2002: Open-file report 03-250, U.S. Geological Survey, Menlo Park, CA.

    Online Links:

    Other_Citation_Details:
    Data from USGS cruises J598SF (<http://walrus.wr.usgs.gov/infobank/j/j598sf/html/j-5-98-sf.meta.html>), J299SF (<http://walrus.wr.usgs.gov/infobank/j/j299sf/html/j-2-99-sf.meta.html>), J399SF (<http://walrus.wr.usgs.gov/infobank/j/j399sf/html/j-3-99-sf.meta.html>), J100SF (<http://walrus.wr.usgs.gov/infobank/j/j100sf/html/j-1-00-sf.meta.html>), P100SF (<http://walrus.wr.usgs.gov/infobank/p/p100sf/html/p-1-00-sf.meta.html>), P200SF (<http://walrus.wr.usgs.gov/infobank/p/p200sf/html/p-2-00-sf.meta.html>), P101SF (<http://walrus.wr.usgs.gov/infobank/p/p101sf/html/p-1-01-sf.meta.html>), P201SF (<http://walrus.wr.usgs.gov/infobank/p/p201sf/html/p-2-01-sf.meta.html>), P301SF (<http://walrus.wr.usgs.gov/infobank/p/p301sf/html/p-3-01-sf.meta.html>), P401SF (<http://walrus.wr.usgs.gov/infobank/p/p401sf/html/p-4-01-sf.meta.html>), and P102SF (<http://walrus.wr.usgs.gov/infobank/p/p102sf/html/p-1-02-sf.meta.html>.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -122.14047
    East_Bounding_Coordinate: -121.93249
    North_Bounding_Coordinate: 38.15529
    South_Bounding_Coordinate: 38.03148

  3. What does it look like?

    OFR_03-250 (JPG)
    Screen grab of GIS-produced sample distribution, with bathymetry and land for reference.

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

    Beginning_Date: 25-Nov-1998
    Ending_Date: 23-Jan-2002
    Currentness_Reference: Publication date

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

    Geospatial_Data_Presentation_Form: Digital

  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):

      • Point (280)

    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 0.00001. Longitudes are given to the nearest 0.00001. Latitude and longitude values are specified in Decimal degrees.

  7. How does the data set describe geographic features?

    Point
    SDTS point (Source: Source report)

    Sample number
    Sample number (Source: US Geological Survey)

    Alpha numeric number based on cruise and core information

    Subsample depth
    Depth of subsample within sample (top = 0) (Source: Source report)

    Range of values
    Minimum:0
    Maximum:0.01
    Units:Meters
    Resolution:0.01

    Gravel
    Amount of gravel in subsample (Source: Source report)

    Range of values
    Minimum:0
    Maximum:16.45
    Units:Percent
    Resolution:0.01

    Sand
    Amount of sand in subsample (Source: Source report)

    Range of values
    Minimum:0.17
    Maximum:99.51
    Units:Percent
    Resolution:0.01

    Silt
    Amount of silt in subsample (Source: Source report)

    Range of values
    Minimum:0.35
    Maximum:72.32
    Units:Percent
    Resolution:0.01

    Clay
    Amount of clay in subsample (Source: Source report)

    Range of values
    Minimum:0.09
    Maximum:69.85
    Units:Percent
    Resolution:0.01

    Mud
    Amount of mud in subsample (Source: Source report)

    Range of values
    Minimum:0.49
    Maximum:99.83
    Units:Percent
    Resolution:0.01

    Median
    Median grain size (Source: Source report)

    Range of values
    Minimum:1.1
    Maximum:9.34
    Units:Phi
    Resolution:0.01

    Mean
    First moment of grain-size distribution (mean) (Source: Source report)

    Range of values
    Minimum:1.21
    Maximum:9.54
    Units:Phi
    Resolution:0.01

    Sorting
    Second moment of grain-size distribution (standard deviation) (Source: Source report)

    Range of values
    Minimum:0.58
    Maximum:3.8
    Units:Phi
    Resolution:0.01

    Skewness
    Third moment of grain-size distribution (skewness) (Source: Source report)

    Range of values
    Minimum:-1.02
    Maximum:5.74
    Units:Unitless
    Resolution:0.01

    Kurtosis
    Fourth moment of grain-size distribution (kurtosis) (Source: Source report)

    Range of values
    Minimum:1.65
    Maximum:73.13
    Units:Unitless
    Resolution:0.01

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?

    Margaret A. Hampton, Noah P. Snyder, John L. Chin, Dan W. Allison, David M. Rubin at the United States geological Survey for the collection and analysis of the data. For usSEABED, formatting: Jane Reid (USGS); Formatting corrections: Jane Reid (USGS) and Chris Jenkins (University of Colorado)

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

    United States Geological Survey
    USGS Information Services
    Denver, CO 80225

    1-800-ASK-USGS (voice)

Why was the data set created?

" ........ to characterize bed-sediment texture and investigate temporal trends in sedimentation."

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: Unknown (process 1 of 1)
    See report: <http://geopubs.wr.usgs.gov/open-file/of03-250/of03-250.pdf>

  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?

    See report ://geopubs.wr.usgs.gov/open-file/of03-250/of03-250.pdf. For usSEABED, digitized data were incorporated as is. Where appropriate, data were tested for completeness using MS Excel. Locations checked using GIS.

  2. How accurate are the geographic locations?

    See report <http://geopubs.wr.usgs.gov/open-file/of03-250/of03-250.pdf>

  3. How accurate are the heights or depths?

    See report <http://geopubs.wr.usgs.gov/open-file/of03-250/of03-250.pdf>

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

    See report. For inclusion into usSEABED, all data in the report were included.

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

    From the report: "In order to facilitate comparisons between the samples, we omitted the coarsest material (>1 mm) from the RV Johnston samples for the computer analysis. We made this change for two reasons: 1) this size category was processed using different methods at various times during the study, and therefore not quantitatively comparable; and 2) we found that in nearly every case the coarsest material was predominately composed of shells and not elastic sediment. By omitting this category from the analysis, we aided comparisons between the data sets, and reduced skewing of the statistics by non-bed-sediment material. However, we chose not to omit this size fraction from the RV Polaris analyses due to the consistent methodology used in processing the samples."

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints:
Report is available online in PDF format; Adobe Acrobat Reader required to view.
Use_Constraints: Cite the U.S. Geological Survey as the originators of the data.

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

    United States Geological Survey
    USGS Information Services
    Denver, CO 80225

    1-800-ASK-USGS (voice)

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

    Open file report 03-250

  3. What legal disclaimers am I supposed to read?

    Although this dataset has been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data. Users of the data should be aware of limitations of the data due to possible imprecision due to navigational inaccuracies and limitations of the statistical data.

  4. How can I download or order the data?

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

    Adobe Acrobat required: Download: <http://www.adobe.com/products/acrobat/readermain.html>

Who wrote the metadata?

Dates:
Last modified: 2005
Metadata author:
U.S. Geological Survey
c/o Jane A. Reid
Geologist
400 Natural Bridges Drive
Santa Cruz, CA 95060

831-427-4727 (voice)
jareid@usgs.gov

Contact_Instructions: Email preferred
Metadata standard:
CSDGM Version 2 (FGDC-STD-001-1998)

Generated by mp version 2.8.17 on Sun May 21 08:11:32 2006