Sediment data from vibracores collected in January 2015 from around Breton Island, Louisiana (U.S. Geological Survey Field Activity Number 2014–336–FA)

USGS scientists collected 56 vibracores from around Breton Island in January 2015 (U.S. Geological Survey Field Activity Number 2014–336–FA). Cores were collected from the M/V Thunderforce, a 110-foot steel multiuse vessel operated by American Vibracore Services (AVS). This vessel uses an A-frame to lift the vibracore base onto the seafloor. An Alpine pneumatic vibracore head attached to a 5.08-cm (4-inch) diameter steel barrel with 9.21-cm (3.625-inch) diameter polycarbonate core liners was used to collect most of the samples. For the nine cores designated for optically stimulated luminescence (OSL) dating, a 7.62-cm (3-inch) diameter aluminum core barrel was used to shield the recovered sediments from light. A penetrometer with proprietary software developed by AVS was incorporated for real-time monitoring and recording of subsurface penetration. After extraction, each core was capped, sealed, and labeled with core number and orientation. The cores were transported to the USGS SPCMSC sediment lab for processing and analysis.

Core locations were recorded at the time of collection using a Furuno depth sounder located amidship of the M/V Thunderforce.

Surface elevations of the core sites were extracted from a 100-meter by 100-meter gridded surface of USGS bathymetric data collected in July 2014 (DeWitt and others, 2016) using the Spatial Analyst Extract Values to Points tool in Esri ArcGIS version 10.2.

At the SPCMSC sediment laboratory, the cores were split lengthwise, photographed with a Canon Powershot SX20 IS digital camera, described macroscopically using standard sediment-logging methods, and subsampled for grain-size analysis. Grain-size samples consisted of 2-cm sections sampled at varying intervals down-core depending on the number and thickness of the observed sedimentologic units. Textural descriptions for the core logs are based on macroscopic observations; the quantitative grain-size data are represented by down-core plots on the core logs. Sediment color is based on the Munsell soil color system.

Grain-size analyses were performed using Coulter LS 200 and Coulter LS 13 320 particle-size analyzers, which use laser diffraction to measure the size distribution of sediments ranging in size from 0.4 microns (µm) to 2 millimeters (mm) (clay to very coarse-grained sand). A total of 1,672 samples from 56 vibracores were analyzed. Core samples consisted of approximately 2-cm sections of the core. In order to prevent shell fragments from damaging the Coulter analyzers, particles greater than 1 mm in diameter were separated from all samples prior to analysis using a number 18 (1000 µm, 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. Prior to sieving, samples were homogenized in the sample bag and wet-sieved to remove any large particles. Two subsamples from each sample were processed through the LS 200 or the LS 13 320 particle-size analyzers a minimum of three runs each. These instruments measure 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). The size-classification boundaries for each bin were specified on the basis of the ASTM E11 standard.

The raw grain-size data were run through the free, widely available program GRADISTAT (Blott and Pye, 2001), which calculates the geometric (in metric units) and logarithmic (in phi units, Φ; Krumbein, 1934) mean, sorting, skewness, and kurtosis of each sample using the Folk and Ward (1957) method as well as the cumulative particle-size distribution. 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 developed by the USGS was applied to calculate the average and standard deviation of each sample (six runs per sample) and highlight runs that varied from the set average by more than plus or minus (±) 1.5 standard deviations. Excessive deviations from the mean are likely the result of equipment error or extraneous material in the sample and are not considered representative of the sample. Those runs were removed from the results and the sample average was recalculated using the remaining runs. The individual run statistics are available from https://coastal.er.usgs.gov/data-release/doi-F79C6VKF/data/2014-336-FA_GrainSize_RunStats.zip. The averaged results for all samples, including the number of runs used, the standard deviation of the averaged results, and class-size distributions, are summarized in a series of Excel workbooks with each core on its own tab and are available from https://coastal.er.usgs.gov/data-release/doi-F79C6VKF/data/2014-336-FA_GrainSize_SumStats.zip.

Using Exchangeable image file format (Exif) data, the GPS date, time and coordinates recorded during sediment core collection were embedded in the whole-core (CoreID.jpg) and stitched (CoreID_sc_adj.jpg) image metadata. The Exif headers were initially populated by the camera’s imaging software but were subsequently updated by USGS staff to include core-related supplemental information. A Python version 2.7.3 script (UpdatePhotoEXIFv2.py) was run to incorporate location information and auxiliary details into the appropriate locations within the Exif header of each full-resolution JPEG image. The Python script used ExifTool version 10.25 to write the information to the image headers. The following tags were populated in the JPEG image headers. Information is duplicated in some tags. This was done because different software packages access different tags.
GPS tags: The values populated are unique for each image and based on the information exported from the handheld GPS.

GPSLatitudeRef
GPSLatitude
GPSLongitudeRef
GPSLongitude
GPSTimeStamp
GSPDateStamp

JPEG tags: The tag is listed along with the information used to populate it - which is the same for every image taken with a particular camera. The following information is based on the Canon PowerShot SX20 IS camera.

comment: Photo of core collected in January 2015 from Breton and Gosier Islands, Louisiana during field activity number 2014–336–FA (https://cmgds.marine.usgs.gov/fan_info.php?fan=2014-336-FA). Published as USGS data release DOI:10.5066/F79C6VKF.

EXIF tags: The tag is listed along with the information used to populate it - which is the same for every image.

ImageDescription: Photograph of sediment core collected from Breton National Wildlife Refuge, LA during 2014–336–FA.

Artist: U.S. Geological Survey
Copyright: Public Domain - please credit U.S. Geological Survey

IPTC tags: The tag is listed along with the information used to populate it - which is the same for every image.

Credit: U.S. Geological Survey
Contact: gs-g-spcmsc_data_inquiries@usgs.gov
Keywords: Breton National Wildlife Refuge, Louisiana, Breton Island, Gosier Island, 2014-336-FA, push-core, grab sample, vibracore, USGS
CopyrightNotice: Public Domain - please credit U.S. Geological Survey
Caption-Abstract: Photograph of sediment core collected from Breton National Wildlife Refuge, LA during 2014–336–FA.

XMP tags: The tag is listed along with the information used to populate it - which is the same for every image.

Caption: Photograph of sediment core collected from Breton National Wildlife Refuge, LA during 2014–336–FA.

To extract the information from the image headers using ExifTool, the following command can be used (tested with ExifTool version 10.25):

exiftool.exe -csv -f -filename -GPSTimeStamp -GPSLongitude -GPSLatitude -n -Artist -Credit -comment -keywords -Caption -Copyright -CopyrightNotice -Caption-Abstract -ImageDescription photos/*.jpg > out.csv

The -csv flag writes the information out in a comma-delimited format. The -n option formats the latitude and longitude as signed decimal degrees.

Added keywords section with USGS persistent identifier as theme keyword.