Surface-sediment grain-size distributions of the Elwha River delta, Washington, July and August 2023

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What does this data set describe?

Title:
Surface-sediment grain-size distributions of the Elwha River delta, Washington, July and August 2023
Abstract:
Surface-sediment grain-size data are derived from samples collected on the Elwha River delta, Washington, in July and August 2023 (USGS Field Activity 2023-645-FA). Surface sediment was collected from 76 locations using a small ponar, or 'grab', sampler from the R/V Dogfish in water depths between about 1 and 17 m around the delta. An additional 18 samples were collected by hand at low tide. The grain size distributions of suitable samples were determined using standard techniques developed by the USGS Pacific Coastal and Marine Science Center sediment lab.
Supplemental_Information:
Additional information about the field activities from which these data were derived is available online at:
https://cmgds.marine.usgs.gov/fan_info.php?fan=2023-645-FA
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  1. How might this data set be cited?
    Stevens, Andrew W., Gelfenbaum, Guy R., Warrick, Jonathan A., Miller, Ian M., and Weiner, Heather M., 20251206, Surface-sediment grain-size distributions of the Elwha River delta, Washington, July and August 2023: data release DOI:10.5066/P1BGEMN5, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    Stevens, Andrew W., Gelfenbaum, Guy R., Warrick, Jonathan A., Miller, Ian M., and Weiner, Heather M., 2025, Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, July and August 2023: data release DOI:10.5066/P1BGEMN5, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

    Online Links:

    Other_Citation_Details:
    Suggested Citation: Stevens, A.W., Gelfenbaum, G.R., Warrick, J.A., Miller, I.M., and Weiner, H.M., 2025, Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, July and August 2023: U.S. Geological Survey data release, https://doi.org/10.5066/P1BGEMN5.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -123.583812
    East_Bounding_Coordinate: -123.480646
    North_Bounding_Coordinate: 48.154357
    South_Bounding_Coordinate: 48.133040
  3. What does it look like?
    grainsize_sampling.jpg (JPG)
    Photo showing collection of sediment samples used for grain size analysis.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 30-Jul-2023
    Ending_Date: 02-Aug-2023
    Currentness_Reference:
    Ground condition at time data were collected
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: comma-delimited text
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (94)
    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 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is WGS1984.
      The ellipsoid used is WGS1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    ew23_grainsize.csv
    Table containing attribute information associated with the dataset (Source: Producer defined)
    Sample_ID
    Name of sample (Source: producer defined) Unique identifier for the sample used given in the field
    Date_Collected
    Date of sample collection in yyyy/mm/dd format (Source: producer defined)
    Range of values
    Minimum:2023/07/30
    Maximum:2023/08/02
    Units:Dates in yyyy/mm/dd format
    Time_GMT
    Time of sample collection in HH:MM:SS format relative to Greenwich Mean Time (GMT) (Source: producer defined)
    Range of values
    Minimum:00:00:00
    Maximum:23:59:59
    Units:Times in HH:MM:SS format
    Latitude
    Latitude of sample in decimal degrees, north (Source: producer defined)
    Range of values
    Minimum:48.139647
    Maximum:48.154548
    Units:decimal degrees
    Longitude
    Longitude of sample in decimal degrees, east (Source: producer defined)
    Range of values
    Minimum:-123.583875
    Maximum:-123.535570
    Units:decimal degrees
    Type
    Type of sample collected (Source: Produce defined)
    ValueDefinition
    SurfaceSample collected on land by hand
    GrabSample collected with grab sampler from boat
    Sample_recovered
    Flag to indicate whether sample was recovered (Source: producer defined)
    ValueDefinition
    YesSample collection successful at site, sample collected
    NoSample collection unsuccessful, no sample recovered
    -4.00phi_16mm
    Weight percent of sample with grain diameter greater than -4.00 phi, or 16 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -3.75phi_13.5mm
    Weight percent of sample with grain diameter between -4.00 and -3.75 phi, or 13.5 and 16 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -3.50phi_11.2mm
    Weight percent of sample with grain diameter between -3.75 and -3.50 phi, or 11.2 and 13.5 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -3.25phi_9.51mm
    Weight percent of sample with grain diameter between -3.50 and -3.25 phi, or 9.51 and 11.2 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -3.00phi_8mm
    Weight percent of sample with grain diameter between -3.25 and -3.00 phi, or 8 and 9.51 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -2.75phi_6.73mm
    Weight percent of sample with grain diameter between -3.00 and -2.75 phi, or 6.73 and 8 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -2.50phi_5.66mm
    Weight percent of sample with grain diameter between -2.75 and -2.50 phi, or 5.66 and 6.73 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -2.25phi_4.76mm
    Weight percent of sample with grain diameter between -2.50 and -2.25 phi, or 4.76 and 5.66 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -2.00phi_4mm
    Weight percent of sample with grain diameter between -2.25 and -2.00 phi, or 4 and 4.76 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -1.75phi_3.36mm
    Weight percent of sample with grain diameter between -2.00 and -1.75 phi, or 3.36 and 4 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -1.50phi_2.83mm
    Weight percent of sample with grain diameter between -1.75 and -1.50 phi, or 2.83 and 3.36 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -1.25phi_2.38mm
    Weight percent of sample with grain diameter between -1.50 and -1.25 phi, or 2.38 and 2.83 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -1.00phi_2mm
    Weight percent of sample with grain diameter between -1.25 and -1.00 phi, or 2 and 2.38 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -0.75phi_1.68mm
    Weight percent of sample with grain diameter between -1.00 and -0.75 phi, or 1.68 and 2 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -0.50phi_1.41mm
    Weight percent of sample with grain diameter between -0.75 and -0.50 phi, or 1.41 and 1.68 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    -0.25phi_1.19mm
    Weight percent of sample with grain diameter between -0.50 and -0.25 phi, or 1.19 and 1.41 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    0.00phi_1mm
    Weight percent of sample with grain diameter between -0.25 and 0.00 phi, or 1 and 1.19 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    0.25phi_0.8409mm
    Weight percent of sample with grain diameter between 0.00 and 0.25 phi, or 0.8409 and 1 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    0.50phi_0.7071mm
    Weight percent of sample with grain diameter between 0.25 and 0.50 phi, or 0.7071 and 0.8409 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    0.75phi_0.5946mm
    Weight percent of sample with grain diameter coarser than 0.75 phi or 0.5946 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    1.00phi_0.5mm
    Weight percent of sample with grain diameter coarser than 1.00 phi or 0.5 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    1.25phi_0.4204mm
    Weight percent of sample with grain diameter coarser than 1.25 phi or 0.4204 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    1.50phi_0.3536mm
    Weight percent of sample with grain diameter coarser than 1.50 phi or 0.3536 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    1.75phi_0.2973mm
    Weight percent of sample with grain diameter coarser than 1.75 phi or 0.2973 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    2.00phi_0.25mm
    Weight percent of sample with grain diameter coarser than 2.00 phi or 0.25 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    2.25phi_0.2102mm
    Weight percent of sample with grain diameter coarser than 2.25 phi or 0.2102 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    2.50phi_0.1768mm
    Weight percent of sample with grain diameter coarser than 2.50 phi or 0.1768 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    2.75phi_0.1487mm
    Weight percent of sample with grain diameter coarser than 2.75 phi or 0.1487 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    3.00phi_0.125mm
    Weight percent of sample with grain diameter coarser than 3.00 phi or 0.125 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    3.25phi_0.1051mm
    Weight percent of sample with grain diameter coarser than 3.25 phi or 0.1051 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    3.50phi_0.088388mm
    Weight percent of sample with grain diameter coarser than 3.50 phi or 0.088388 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    3.75phi_0.074325mm
    Weight percent of sample with grain diameter coarser than 3.75 phi or 0.074325 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    4.00phi_0.0625mm
    Weight percent of sample with grain diameter coarser than 4.00 phi or 0.0625 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    4.25phi_0.052556mm
    Weight percent of sample with grain diameter coarser than 4.25 phi or 0.052556 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    4.50phi_0.044194mm
    Weight percent of sample with grain diameter coarser than 4.50 phi or 0.044194 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    4.75phi_0.037163mm
    Weight percent of sample with grain diameter coarser than 4.75 phi or 0.037163 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    5.00phi_0.03125mm
    Weight percent of sample with grain diameter coarser than 5.00 phi or 0.03125 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    5.25phi_0.026278mm
    Weight percent of sample with grain diameter coarser than 5.25 phi or 0.026278 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    5.50phi_0.022097mm
    Weight percent of sample with grain diameter coarser than 5.50 phi or 0.022097 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    5.75phi_0.018581mm
    Weight percent of sample with grain diameter coarser than 5.75 phi or 0.018581 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    6.00phi_0.015625mm
    Weight percent of sample with grain diameter coarser than 6.00 phi or 0.015625 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    6.25phi_0.013139mm
    Weight percent of sample with grain diameter coarser than 6.25 phi or 0.013139 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    6.50phi_0.011049mm
    Weight percent of sample with grain diameter coarser than 6.50 phi or 0.011049 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    6.75phi_0.009291mm
    Weight percent of sample with grain diameter coarser than 6.75 phi or 0.009291 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    7.00phi_0.007813mm
    Weight percent of sample with grain diameter coarser than 7.00 phi or 0.007813 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    7.25phi_0.00657mm
    Weight percent of sample with grain diameter coarser than 7.25 phi or 0.00657 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    7.50phi_0.005524mm
    Weight percent of sample with grain diameter coarser than 7.50 phi or 0.005524 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    7.75phi_0.004645mm
    Weight percent of sample with grain diameter coarser than 7.75 phi or 0.004645 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    8.00phi_0.003906mm
    Weight percent of sample with grain diameter coarser than 8.00 phi or 0.003906 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    8.25phi_0.003285mm
    Weight percent of sample with grain diameter coarser than 8.25 phi or 0.003285 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    8.50phi_0.002762mm
    Weight percent of sample with grain diameter coarser than 8.50 phi or 0.002762 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    8.75phi_0.002323mm
    Weight percent of sample with grain diameter coarser than 8.75 phi or 0.002323 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    9.00phi_0.001953mm
    Weight percent of sample with grain diameter coarser than 9.00 phi or 0.001953 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    9.25phi_0.001642mm
    Weight percent of sample with grain diameter coarser than 9.25 phi or 0.001642 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    9.50phi_0.001381mm
    Weight percent of sample with grain diameter coarser than 9.50 phi or 0.001381 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    9.75phi_0.001161mm
    Weight percent of sample with grain diameter coarser than 9.75 phi or 0.001161 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    10.00phi_0.000983mm
    Weight percent of sample with grain diameter coarser than 10.00 phi or 0.000983 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    10.25phi_0.000821mm
    Weight percent of sample with grain diameter coarser than 10.25 phi or 0.000821 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    10.50phi_0.000691mm
    Weight percent of sample with grain diameter coarser than 10.50 phi or 0.000691 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    10.75phi_0.000581mm
    Weight percent of sample with grain diameter coarser than 10.75 phi or 0.000581 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    11.00phi_0.000492mm
    Weight percent of sample with grain diameter coarser than 11.00 phi or 0.000492 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    11.25phi_0.000411mm
    Weight percent of sample with grain diameter coarser than 11.25 phi or 0.000411 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    11.50phi_0.00035mm
    Weight percent of sample with grain diameter coarser than 11.50 phi or 0.00035 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    12.00phi_0.000241mm
    Weight percent of sample with grain diameter coarser than 12.00 phi or 0.000241 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    13.00phi_0.00012mm
    Weight percent of sample with grain diameter coarser than 13.00 phi or 0.00012 mm. NaN=not a number, because no sample was recovered. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    Percent_Gravel
    percent of sample greater than 2 mm. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    Percent_Sand
    percent of sample less than 2 mm and greater than 63 microns. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    Percent_Silt
    percent of sample less than 63 microns and greater than 4 microns. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    Percent_Clay
    percent of sample less than 4 microns. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    Percent_Mud
    percent of sample less than 63 microns. (Source: producer defined)
    Range of values
    Minimum:0
    Maximum:100
    Units:percentage
    D5_percent_coarser_in_phi
    Phi size at D5 for sample. (Source: producer defined)
    Range of values
    Minimum:-4
    Maximum:2.15
    Units:Phi size
    D10_percent_coarser_in_phi
    Phi size at D10 for sample. (Source: producer defined)
    Range of values
    Minimum:-4
    Maximum:2.37
    Units:Phi size
    D16_percent_coarser_in_phi
    Phi size at D16 for sample. (Source: producer defined)
    Range of values
    Minimum:-4
    Maximum:2.56
    Units:Phi size
    D25_percent_coarser_in_phi
    Phi size at D25 for sample. (Source: producer defined)
    Range of values
    Minimum:-4
    Maximum:2.82
    Units:Phi size
    D50_percent_coarser_in_phi
    Phi size at D50, or average particle diameter by mass, for sample. (Source: producer defined)
    Range of values
    Minimum:-4
    Maximum:3.34
    Units:Phi size
    D75_percent_coarser_in_phi
    Phi size at D75 for sample. (Source: producer defined)
    Range of values
    Minimum:-4
    Maximum:4.20
    Units:Phi size
    D84_percent_coarser_in_phi
    Phi size at D84 for sample. (Source: producer defined)
    Range of values
    Minimum:-4
    Maximum:6.40
    Units:Phi size
    D90_percent_coarser_in_phi
    Phi size at D90 for sample. (Source: producer defined)
    Range of values
    Minimum:-4
    Maximum:7.50
    Units:Phi size
    D95_percent_coarser_in_phi
    Phi size at D95 for sample. (Source: producer defined)
    Range of values
    Minimum:-4
    Maximum:8.67
    Units:Phi size
    Folk_Ward_Median_percent_coarser
    Phi size median for sample by Folk and Ward (1957) method. (Source: producer defined)
    Range of values
    Minimum:-4.00
    Maximum:3.34
    Units:Phi size
    Folk_Ward_Mean_percent_coarser
    Phi size mean for sample by Folk and Ward (1957) method. (Source: producer defined)
    Range of values
    Minimum:-4.00
    Maximum:4.10
    Units:Phi size
    Folk_Ward_Sorting_percent_coarser
    sorting for sample by Folk and Ward (1957) method. (Source: producer defined)
    Range of values
    Minimum:0.00
    Maximum:2.87
    Units:Phi size
    Folk_Ward_Skewness_percent_coarser
    skewness for sample by Folk and Ward (1957) method. (Source: producer defined)
    Range of values
    Minimum:-2.15
    Maximum:1.00
    Units:Phi size
    Folk_Ward_Kurtosis_percent_coarser
    Kurtosis for sample by Folk and Ward (1957) method. (Source: producer defined)
    Range of values
    Minimum:0.00
    Maximum:13.19
    Units:Phi size
    Inman_Median_percent_coarser
    Phi size median for sample by Inman (1952) method. (Source: producer defined)
    Range of values
    Minimum:-4.00
    Maximum:3.34
    Units:Phi size
    Inman_Mean_percent_coarser
    Phi size mean for sample by Inman (1952) method. (Source: producer defined)
    Range of values
    Minimum:-4.00
    Maximum:4.48
    Units:Phi size
    Inman_Sorting_percent_coarser
    sorting for sample by Inman (1952) method. (Source: producer defined)
    Range of values
    Minimum:0.00
    Maximum:2.89
    Units:Phi size
    Inman_Skew_16_84_percent_coarser
    skewness for sample (D16-D84) by Inman (1952) method. (Source: producer defined)
    Range of values
    Minimum:-2.93
    Maximum:1.00
    Units:Phi size
    Inman_Skew_05_95_percent_coarser
    skewness for sample (D5-D95) by Inman (1952) method. (Source: producer defined)
    Range of values
    Minimum:-2.27
    Maximum:9.49
    Units:Phi size
    Inman_Kurtosis_percent_coarser
    Kurtosis for sample by Inman (1952) method. (Source: producer defined)
    Range of values
    Minimum:-0.36
    Maximum:8.49
    Units:Phi size
    1_Moment_Mean_Phi
    moment measure of mean. (Source: producer defined)
    Range of values
    Minimum:-4.00
    Maximum:4.01
    Units:Phi size
    2_Moment_Variance
    moment measure of variance. (Source: producer defined)
    Range of values
    Minimum:0.00
    Maximum:9.78
    Units:Phi size
    2_Moment_Standard_Deviation
    moment measure of standard deviation. (Source: producer defined)
    Range of values
    Minimum:0.00
    Maximum:3.13
    Units:Phi size
    3_Moment_Skewness
    moment measure of skewness. (Source: producer defined)
    Range of values
    Minimum:0.00
    Maximum:15.65
    Units:Phi size
    4_Moment_Kurtosis
    moment measure of kurtosis. (Source: producer defined)
    Range of values
    Minimum:0.00
    Maximum:304.24
    Units:Phi size
    Entity_and_Attribute_Overview: The first line of the csv file is a header line.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Andrew W. Stevens
    • Guy R. Gelfenbaum
    • Jonathan A. Warrick
    • Ian M. Miller
    • Heather M. Weiner
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Attn: PCMSC Science Data Coordinator
    2885 Mission Street
    Santa Cruz, CA

    831-427-4747 (voice)
    pcmsc_data@usgs.gov

Why was the data set created?

Data were obtained to assess the coastal geomorphic response following the removal of two dams on the Elwha River. These data are intended for science researchers, students, policy makers, and the general public.

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: 02-Aug-2023 (process 1 of 2)
    Surface sediment was collected on July 30, 2023, at a total of 76 locations using a small ponar, or 'grab', sampler from the R/V Frontier in water depths between about 1 and 17 m around the delta. An additional 18 samples were collected by hand at low tide on August 2, 2023. A hand-held global satellite navigation system (GNSS) receiver was used to determine the locations of sediment samples. Grab samples that yielded less than 50 g of sediment were omitted from analysis.
    Date: 06-Jan-2025 (process 2 of 2)
    The grain-size distributions of suitable samples were determined in the USGS Pacific Coastal and Marine Science Center sediment lab. Approximately 20 g of sediment was sub-sampled and 10 mL of 35 percent hydrogen peroxide was added to remove organic material in the sample. The sample was heated at 250 degrees C to remove any remaining hydrogen peroxide and was placed in an ultrasonic bath to liberate the fine fraction. Subsequently, the sample was centrifuged for 1.5 hours to remove soluble salts. Samples were funneled through 2 mm and 63 um sieves to separate the gravel (greater than 2 mm), sand (63 um to 2 mm), and mud (less than 63 um). The sand and gravel fractions were dried in an 80-degree C oven and weighed. Five mL of sodium hexametaphosphate was added to the mud fraction and a 20 mL aliquot was taken from a 1 L graduated cylinder to determine the weight of the mud. The particle-size distribution of the mud and sand fractions was analyzed separately using a Beckman Coulter LS 13 320, and the gravel, sand, and mud results were integrated into a single grain-size distribution for each sample.
  3. What similar or related data should the user be aware of?
    Folk, Robert Louis, and Ward, William C., 1957, Brazos River bar; a study in the significance of grain size parameters.

    Online Links:

    Other_Citation_Details:
    Folk, R.L., and Ward, W.C., 1957, Brazos River bar; a study in the significance of grain size parameters: Journal of Sedimentary Research, v. 27, n. 1, p. 3-26.
    Inman, Douglas Lamar, 1952, Measures for describing the size distribution of sediments.

    Online Links:

    Other_Citation_Details:
    Inman, D.L., 1952, Measures for describing the size distribution of sediments: Journal of Sedimentary Research, v. 22, n. 3, p. 125-145.

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    No formal attribute accuracy tests were conducted.
  2. How accurate are the geographic locations?
    The locations of samples were determined using a Garmin 78s handheld global satellite navigation systems (GNSS) receiver capable of receiving wide area augmentation system (WAAS) signals. The manufacturer reported accuracy for horizontal positions is 3-5 m while receiving WAAS signals.
  3. How accurate are the heights or depths?
    No formal positional accuracy tests were conducted
  4. Where are the gaps in the data? What is missing?
    Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
  5. How consistent are the relationships among the observations, including topology?
    No formal logical accuracy tests were conducted.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints No access constraints
Use_Constraints USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. These data are marked with a Creative Common CC0 1.0 Universal License. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data. This information is not intended for navigation purposes.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - Coastal and Marine Geoscience Data System
    2885 Mission Street
    Santa Cruz, CA
    USA

    831-427-4747 (voice)
    pcmsc_data@usgs.gov
  2. What's the catalog number I need to order this data set? Surface-sediment grain-size data are available as a comma-delimited text file (ew23_grainsize.csv), along with associated FGDC-compliant metadata.
  3. What legal disclaimers am I supposed to read?
    Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 06-Dec-2025
Metadata author:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Attn: PCMSC Science Data Coordinator
2885 Mission Street
Santa Cruz, CA

831-427-4747 (voice)
pcmsc_data@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/CMGDS_DR_tool/DR_P1BGEMN5/ew23_grainsize_metadata.faq.html>
Generated by mp version 2.9.51 on Thu Dec 11 12:26:37 2025