Grain-Size and Data Analysis Results from Sediment Samples Collected at Crocker Reef, Florida, Between 2017 and 2019

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Frequently anticipated questions:

What does this data set describe?

Title:
Grain-Size and Data Analysis Results from Sediment Samples Collected at Crocker Reef, Florida, Between 2017 and 2019
Abstract:
Sediment samples were collected from undisturbed sections of the seafloor around Crocker Reef, Florida. Crocker Reef is a barrier reef located in the northern portion of the Florida Reef Tract that has been classified by Kellogg and others (2015) as a senile or dead reef consisting of areas of sand and rubble with only scattered stony coral colonies. Samples were collected from November 2017 to April 2019 to help ground truth coincident instrumentation deployed during the same time interval, which was used to record various oceanic (currents, waves, turbidity, and pressure) time series datasets that would be used in subsequent analyses. All sediment samples were analyzed using a laser diffraction Coulter LS13 320 particle-size analyzer and sieves to measure the grain-size distribution of the sediments.
Supplemental_Information:
To ensure that U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) data management protocols were followed, this survey was assigned the following USGS field activity numbers (FAN): 2017-340-FA, 2018-301-FA, 2018-356-FA, and 2019-301-FA. Additional survey and data details are available from the USGS Coastal and Marine Geoscience Data System (CMGDS) at, https://cmgds.marine.usgs.gov/. The authors would like to acknowledge Hunter Wilcox, Nate Smiley and BJ Reynolds for their assistance with field collection.
  1. How might this data set be cited?
    Torres-Garcia, Legna M., and Everhart, Cheyenne S., 20220121, Grain-Size and Data Analysis Results from Sediment Samples Collected at Crocker Reef, Florida, Between 2017 and 2019:.

    This is part of the following larger work.

    Torres-Garcia, Legna M., Everhart, Cheyenne S., Yates, Kimberly K., Lemon, Mitchell K., Moore, Christopher S., and Buckley, Mark L., 20220121, Grain-Size Data from Upper Florida Keys: Crocker Reef, FL: U.S. Geological Survey data release doi:10.5066/P989A5F5, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -80.56012
    East_Bounding_Coordinate: -80.52272
    North_Bounding_Coordinate: 24.9483
    South_Bounding_Coordinate: 24.90502
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 28-Nov-2017
    Ending_Date: 29-Jul-2019
    Currentness_Reference:
    Ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Tabular digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
    2. What coordinate system is used to represent geographic features?
  7. How does the data set describe geographic features?
    CrockerReef_CoulterGrainSize.xlsx
    Microsoft Excel workbook summarizing grain-size parameters for each sediment sample collected on Crocker Reef and the surrounding area (USGS FANs 2017-340-FA, 2018-301-FA, 2018-356-FA, and 2019-301-FA). The averaged results for each sample, including the number of runs used, and the standard deviation of the averaged results are provided. (Source: USGS)
    CrockerReef_CoulterGrainSize.csv
    CSV text file summarizing grain-size parameters for each sediment sample collected on Crocker Reef and the surrounding area (USGS FANs 2017-340-FA, 2018-301-FA, 2018-356-FA, and 2019-301-FA). The averaged results for each sample, including the number of runs used, and the standard deviation of the averaged results, are provided. (Source: USGS)
    CrockerReef_SieveGrainSize.xlsx
    Microsoft Excel workbook summarizing grain-size distribution derived from sieve analysis for each sediment sample collected on Crocker Reef and the surrounding area (USGS FANs 2017-340-FA, 2018-301-FA, 2018-356-FA, and 2019-301-FA). (Source: USGS)
    CrockerReef_SieveGrainSize.csv
    CSV text file summarizing grain-size distribution derived from sieve analysis for each sediment sample collected on Crocker Reef and the surrounding area (USGS FANs 2017-340-FA, 2018-301-FA, 2018-356-FA, and 2019-301-FA). (Source: USGS)
    Entity_and_Attribute_Overview:
    The detailed attribute descriptions for the grain-size workbooks are provided in the included data dictionaries (CrockerReef_CoulterGrainSize_DataDictionary.pdf and CrockerReef_SieveGrainSize_DataDictionary.pdf). These metadata are not complete without these files.
    Entity_and_Attribute_Detail_Citation:
    The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Legna M. Torres-Garcia
    • Cheyenne S. Everhart
  2. Who also contributed to the data set?
    U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, St. Petersburg Coastal and Marine Science Center
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: Legna M. Torres-Garcia
    Research Oceanographer
    600 4th Street South
    St. Petersburg, FL
    USA

    727-502-8000 (voice)
    ltorresgarica@usgs.gov

Why was the data set created?

Dissemination of processed grain-size data from sediment surface samples collected from the Upper Florida Keys within Crocker Reef, Florida from 2017-2019.

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: 2019 (process 1 of 4)
    Surface sediment samples were collected by USGS SPCMSC Self-Contained Underwater Breathing Apparatus (SCUBA) divers at 7-8 different locations within the Crocker Reef study site during 2017-2018 and 10 locations during 2018-2019. The sediment sampling sites’ water depths ranged from 2 to 16 meters. SCUBA divers wearing gloves dragged open sampling bags along an undisturbed sediment layer atop the seafloor in a single direction to ensure all grain sizes were sampled. Samples were washed with 95% ethanol to remove contaminants and brought back to the SPCMSC Sediment Laboratory to air dry completely in the fume hood. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Legna M. Torres-Garcia
    Research Oceanographer
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    ltorresgarica@usgs.gov
    Date: 2019 (process 2 of 4)
    Particle size analysis was performed on all the sediment samples collected from the Crocker Reef study site. Grain-size analyses on the samples were performed using a Coulter LS13 320 (https://www.beckmancoulter.com/) particle-size analyzer (PSA), that used laser diffraction to measure the size distribution of sediments from 0.4 microns to 2 millimeters (mm), encompassing clay to very coarse-grained sand. To prevent large shell fragments from damaging the instrument, particles greater than 1 mm in diameter were separated from all samples prior to analysis using a number 18 (1 mm) U.S. standard sieve, which meets the American Society for Testing and Materials (ASTM) E11 standard specifications for determining particle size using woven-wire test sieves. The material removed by sieving at 1 mm is recorded and reported as a percent of the total bulk dry weight with the final processed grain-size data. Two subsamples from each sample were processed through the instrument a minimum of four runs each. Once introduced into the Coulter PSA the sediment in the sample well was sonicated with a sonicator wand for 30 seconds to separate any aggregates before starting the first run for both subsamples. The Coulter PSA measures the particle-size distribution of each sample by passing sediment suspended in solution between two narrow panes of glass in front of a laser. Light is scattered by the particles into characteristic refraction patterns measured by an array of photodetectors as intensity per unit area and recorded as relative volume for 92 size-related channels (bins). Person who carried out this activity:
    U.S. Geological Survey
    Attn: Legna M. Torres-Garcia
    Research Oceanographer
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    ltorresgarica@usgs.gov
    Date: 2019 (process 3 of 4)
    All raw grain-size data were run through the free software GRADISTAT version 8, (Blott and Pye, 2001; kpal.co.uk/gradistat), which calculates the mean, sorting, skewness and kurtosis of each sample geometrically in metric units and logarithmically in phi units (Φ) (Krumbein, 1934) using the Folk and Ward (1957) scale. GRADISTAT also calculates the fraction of sediment from each sample by size category (for example, clay, coarse silt, fine sand) based on a modified Wentworth (1922) size scale. A macro function in Microsoft Excel, developed by the USGS SPCMSC, was applied to the data to calculate average and standard deviation for each sample set (8 runs per sample), and highlight runs that varied from the set average by more than ±1.5 standard deviations. Excessive deviations from the mean are likely the result of equipment error or extraneous organic material in the sample and are not considered representative of the sample. The highlighted runs were removed from the results and the sample average was recalculated using the remaining runs. The averaged results for all samples, including the number of averaged runs and the standard deviation of the averaged results were summarized in an Excel workbook with samples from each FAN on its own tab. A comma-separated values (CSV) file containing the tabular data in plain text is included in the download file. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Legna M. Torres-Garcia
    Research Oceanographer
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    ltorresgarica@usgs.gov
    Data sources produced in this process:
    • CrockerReef_CoulterGrainSize.xlsx
    Date: 2019 (process 4 of 4)
    Due to the assumption of grain sphericity of the Fraunhofer optical model used by the Coulter LS13 320, angular particles are measured by their longest axis. When enough thin, angular material is present, the Coulter output files often report a percentage of the grain-size distribution within the 1-2 mm fraction, despite all samples being sieved at 1 mm before analysis. To better assess the impact of the high content of angular shell material present at Crocker Reef on the grain-size distribution reported in the Coulter analysis, a dry sieve analysis was performed at the same major size classes for comparison. A 10–15-gram representative subset of each sample was passed through a stack of sieves with progressively smaller openings using the assistance of a mechanical sieve shaker to determine grain-size distribution. U.S. standard sieves numbers 230 (63 µm), 120 (125 µm), 60 (250 µm), 35 (500 µm), 18 (1 mm), and 10 (2 mm) were used, which meet the ASTM E11 standard specifications for determining particle size using woven-wire test sieves. All dry sieve data was reported as a percent fraction of the total bulk dry weight of each sample subset. The results for all samples were summarized in an Excel workbook with samples from each FAN on its own tab. A CSV data file containing the tabular data in plain text is included in the download file. Person who carried out this activity:
    U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Attn: Legna M. Torres-Garcia
    Research Oceanographer
    600 4th Street South
    St. Petersburg, FL
    U.S.

    (727) 502-8000 (voice)
    ltorresgarica@usgs.gov
    Data sources produced in this process:
    • CrockerReef_SieveGrainSize.xlsx
  3. What similar or related data should the user be aware of?
    Coulter, Beckman, 2011, LS 13 320 Laser Diffraction Particle Size Analyzer Instructions For Use.

    Online Links:

    Blott, S.J. and Pye, K., 20010928, GRADISTAT: A grain size distribution and statistics package for the analysis of unconsolidated sediments: Earth Surface Processes and Landforms Volume 26, issue 11.

    Online Links:

    Other_Citation_Details: Pages 1237-1248
    Folk, R.L, and Ward, W.C., 1957, Brazos River Bar: A study in the significance of grain size parameters: Journal of Sedimentary Petrology Volume 27.

    Other_Citation_Details: Pages 3-26
    Kellogg, C.A., Yates, K.K., Lawler, S.N., Moore, C.S., and Smiley, N.A., 20151104, Seasonal microbial and environmental parameters at Crocker Reef, Florida Keys, 2014–2015: U.S. Geological Survey Open-File Report 2015-1203.

    Online Links:

    Krumbien, W.C., 1934, Size frequency distributions of sediments: Journal of Sedimentary Petrology Volume 4, No. 2.

    Other_Citation_Details: pages 65-77
    Wentworth, C.K., 1922, A scale of grade and class terms for clastic sediments: Journal of Geology Volume 30.

    Other_Citation_Details: pages 377-392

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

  1. How well have the observations been checked?
    The grain-size data represent the sample averages for a subset of the statistical parameters calculated by GRADISTAT (Blott and Pye, 2001). The number of runs included in the averaged results are reported, and the standard deviation of the averaged results are reported for most parameters. Samples S1RBRL1112017, SVL5112017, WM1L2112017, and S1RBRL1032018 have more than 8 runs included in the average results because additional subsets of samples were analyzed beyond the standard two subsets. For S1RBRL1112017 and SVL5112017, the obscuration was fluctuating for the first two subsets. For WM1L2112017, the sonicator wand wasn’t fully functioning during the first two subsets. For S1RBRL1032018, the first two subsets had low obscuration and the sonicator wand wasn’t fully functioning. A secondary data review determined that all grain-size data reported met all quality control requirements. Beckman Coulter control standards G15 (15 µm) and GB500 (500 µm) were analyzed on the Coulter LS13 320 particle-size analyzer before all sediment samples were analyzed to validate instrument performance (Beckman Coulter, 2011).
  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 release doi:10.5066/P989A5F5 contains all grain-size data associated with USGS FANs 2017-340-FA, 2018-301-FA, 2018-356-FA, and 2019-301-FA. It includes the geographic site locations and grain-size statistics for all sediment samples collected at Crocker Reef from 2017 to 2019.
  5. How consistent are the relationships among the observations, including topology?
    The grain-size sample runs in the GRADISTAT output files for which the mean Folk and Ward (1957) grain-size varied from the set average by more than 1.5 standard deviations are highlighted in yellow and were not included in final averaged results.

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:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests that it be acknowledged as the originator of this dataset in any future products or research derived from these data.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center
    Attn: Legna M. Torres-Garcia
    Research Oceanographer
    600 4th Street South
    St. Petersburg, FL
    USA

    727-502-8000 (voice)
    ltorresgarcia@usgs.gov
  2. What's the catalog number I need to order this data set? Downloadable data
  3. What legal disclaimers am I supposed to read?
    This publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, 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 imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: This zip archive includes Microsoft Excel spreadsheets (.xlsx), CSV text files (.csv), Portable Document Format (PDF) files and accompanying metadata for grain-size data from sediment samples collected from Crocker Reef, FL (USGS FANs 2017-340-FA, 2018-301-FA, 2018-356-FA, and 2019-301-FA). in format Compressed (zip) archive WinZip, 7-Zip
      Network links: https://coastal.er.usgs.gov/data-release/doi-P989A5F5/data/CrockerReef_GrainSize.zip
    • Cost to order the data: None, if obtained online

  5. What hardware or software do I need in order to use the data set?
    The data tables for USGS FANs 2017-340-FA, 2018-301-FA, 2018-356-FA, and 2019-301-FA were created in Microsoft Excel version 2102 and can be opened using Microsoft Excel 2007 or higher. The data tables are also provided as CSV text files (.csv). The .csv data file contains the tabular data in plain text and may be viewed with a standard text editor. PDF files can be viewed using the free software Adobe Acrobat Reader (http://get.adobe.com/reader).

Who wrote the metadata?

Dates:
Last modified: 21-Jan-2022
Metadata author:
U.S. Geological Survey
Attn: Legna M. Torres-Garcia
Research Oceanographer
600 4th Street South
St. Petersburg, FL
USA

727-502-8000 (voice)
ltorresgarcia@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/CrockerReef_Metadata.faq.html>
Generated by mp version 2.9.50 on Fri Jan 21 12:55:07 2022