The southern Monterey Bay littoral cell: A preliminary sediment budget study

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Frequently-anticipated questions:

What does this data set describe?

Title:
The southern Monterey Bay littoral cell: A preliminary sediment budget study
Abstract:
A sediment budget was developed for southern Monterey Bay, California. This budget is based heavily upon sediment information obtained from field and laboratory studies. These studies included a detailed quasi-synoptic areal sampling to determine distribution of textural patterns, and a time-series study of beach and surf-zone sand samples obtained from local sand-mining companies. Results from these studies were combined with data on river discharge, the wind and wave regimes, and shoreline changes during the past century to develop quantitative estimates of sediment gains and losses to the cell. It was determined that the major sources of sediment are the discharge from the Salinas River which empties into the northeast corner of the cell, and erosion of Quaternary seacliffs which form the inner bay shore. Major sinks are the Monterey Submarine Canyon, active coastal dune fields, the mining companies, and the offshore area. The recent history of the sediment regime in the southern bay is reviewed, and a forecast of future nearshore changes is made. Recommendations for further work needed to refine the budget computations are presented.
Supplemental_Information:
Data digitized by the USGS for inclusion into usSEABED (<http://walrus.wr.usgs.gov/usseabed>)
  1. How should this data set be cited?

    Dorman, Craig E. , 1968, The southern Monterey Bay littoral cell: A preliminary sediment budget study: United States Naval Postgraduate School, Monterey, CA.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -121.9343
    East_Bounding_Coordinate: -121.8178
    North_Bounding_Coordinate: 36.6785
    South_Bounding_Coordinate: 36.6021

  3. What does it look like?

    Dorman_MS_1968 (.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?

    Calendar_Date: 1968
    Currentness_Reference: Publication date

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

    Geospatial_Data_Presentation_Form: Paper

  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 (420 total; 171 useable)

    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 0.0001. Longitudes are given to the nearest 0.0001. Latitude and longitude values are specified in Decimal degrees.

  7. How does the data set describe geographic features?

    Point
    SDTS point (Source: Source report)

    Pan size 3.962
    Sample value larger than 3.962 mm grain size (Source: Dorman, 1968)

    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.0001

    Pan size 1.981
    Sample value between 3.962 and 1.981 mm grain size (Source: Dorman, 1968)

    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.0001

    Pan size 0.991
    Sample value between 1.981 and 0.991 mm grain size (Source: Dorman, 1968)

    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.0001

    Pan size 0.495
    Sample value between 0.991 and 0.495 mm grain size (Source: Dorman, 1968)

    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.0001

    Pan size 0.351
    Sample value between 0.495 and 0.351 mm grain size (Source: Dorman, 1968)

    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.0001

    Pan size 0.246
    Sample value between 0.351 and 0.246 mm grain size (Source: Dorman, 1968)

    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.0001

    Pan size 0.175
    Sample value between 0.246 and 0.175 mm grain size (Source: Dorman, 1968)

    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.0001

    Pan size 0.124
    Sample value between 0.175 and 0.124 mm grain size (Source: Dorman, 1968)

    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.0001

    Pan size 0.088
    Sample value between 0.124 and 0.088 mm grain size (Source: Dorman, 1968)

    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.0001

    Pan size 0.061
    Sample value between 0.088 and 0.061 mm grain size (Source: Dorman, 1968)

    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.0001

    Pan size 0
    Sample value between 0.061 and 0 mm grain size (Source: Dorman, 1968)

    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.0001

    Median
    Median of grain size distribution (Source: Inman,1952)

    Range of values
    Minimum:-0.727
    Maximum:3.286
    Units:Phi
    Resolution:0.001

    Mean
    Mean of grain size distribution (Source: Inman, 1952)

    Range of values
    Minimum:-0.835
    Maximum:3.533
    Units:Phi
    Resolution:0.001

    Deviation
    Standard deviation of grain size distribution (sorting) (Source: Inman, 1952)

    Range of values
    Minimum:0.31
    Maximum:2.268
    Units:Phi
    Resolution:0.001

    Skewness1
    First skewness of grain size distribution (Source: Inman, 1952)

    Range of values
    Minimum:-0.483
    Maximum:0.686
    Units:Unitless
    Resolution:0.001

    Skewness2
    Second skewness of grain size distribution (Source: Inman, 1952)

    Range of values
    Minimum:-1.848
    Maximum:1.95
    Units:Phi
    Resolution:0.001

    Kurtosis
    Kurtosis (Source: Inman, 1952)

    Range of values
    Minimum:-0.112
    Maximum:3.277
    Units:Phi
    Resolution:0.001

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?

    Craig E. Dorman at the United States Naval Postgraduate School for the collection and analysis of data. For inclusion into usSEABED: Digitization (data): Jennifer Mendonca and Carolynn Box (USGS); locations: Nadine Golden (USGS). Formatting corrections: Jane Reid (USGS) and Chris Jenkins (University of Colorado).

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

    U.S. Naval Postgraduate School
    1 University Circle
    Monterey, CA 93943

    831.656.2441 (voice)

Why was the data set created?

This study deals with the sedimentary environment and the movement of sediments in the southern portion of Monterey Bay, California. The primary purpose of the work was to outline the major factors contributing to the sand budget of the area and to correlate these factors with the present areal patterns of textural properties of the beach and nearshore surface sediments. Because of the magnitude of the task of undertaking a total sand budget study and the incomplete nature of some of the data, emphasis was placed on delineation of the area distribution and seasonal variability of sediment patterns and on littoral transport. Quantitative evaluation of credits and debits to the budget was in most cases quite tentative.

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: 1968 (process 1 of 1)
    Data collected on Naval Postgraduate School 63 foot research vessel using a Dietz-LaFond heavy duty grab and a locally modified clamshell mud snapper. Sample volumes averaged approximately 100 cc (250 grams) and a minimum of 30 grams was obtained at each station. Eleven sieves at half-phi intervals from 4 phi to 1 phi and one-phi intervals from 1 phi to -2 phi were used, with a minimum shaking time of 10 minutes, on samples dried at 140 degrees F for a minimum of 24 hours. Statistical values calculated using a program provided in the report.

    Person who carried out this activity:

    U.S. Naval Postgraduate School
    1 University Circle
    Monterey, CA 93943

    831.656.2441 (voice)

    Data sources produced in this process:
    • Dorman_MS_1968

  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?

    Statistical data was digitized by hand (typed in), visually compared to source and corrected. Where appropriate, data were tested for completeness using MS Excel.

  2. How accurate are the geographic locations?

    Per report: Navigation for offshore stations numbered under 400 was by visual compass bearings. Fathograms and coastline photographs from each station were used for verification of position. Notations of these positions are believed to be accurate to within a 25-yard radius. Stations 401 to 420 were located by radar navigation, assisted by fathograms. The positions of these stations are believed accurate to within a 100-yard radius. Digitization report: Data locations were digitized using ArcGis 8.3 in August 2004 by scanning the location map and georeferencing the coastline to California coastline shapefile. Locations are given to 0.0001 decimal degrees.

  3. How accurate are the heights or depths?

    No water depths are given in the report.

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

    For usSEABED digitized data include Appendix D: Summary of cumulative percents and Appendix E: Summary of phi parameters and percentiles. Phi size class values were determined by iteratively subtracting adjacent cumulative percents. Pan sizes in mm were converted to phi values. Data not digitized include 95%, 84%, 50%, 16% and 05% percentiles, and weight percent of phi classes. Poor reproduction quality of the report did not allow for the location determinations of samples 66-148 and 339-397, which are not included in usSEABED.

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

    Data fall within normal ranges for phi-size classes and Inman, 1952 sediment statistics.

How can someone get a copy of the data set?

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

Access_Constraints: Available at some libraries
Use_Constraints:
Cite Craig Dorman and the U.S. Naval Postgraduate School as the originators of the data.

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

    U.S. Naval Postgraduate School
    1 University Circle
    Monterey, CA 93943

    831.656.2441 (voice)

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

    C. E. Dorman Masters thesis, 1968

  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?

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 Tue May 16 20:57:22 2006