The sediment grain-size data set provided here contains information on the collection, location, description, and texture of sediments at 58 stations occupied during the verification cruise RAFA07034 (fig. 12). All analyses were conducted in the sedimentation laboratory at the USGS's Woods Hole Science Center. Records without textural data and statistics are based on visual descriptions. The basic structure of the data is in “flat-file” format, a matrix where records are rows representing individual samples and the columns contain sample- and station-specific information. This matrix contains 43 fields that are defined in the Data Dictionary below.

The sediment data are provided in two formats: Microsoft Excel and delimited ASCII text format. In the delimited ASCII text file, each field or column of data is separated from the next by a comma and can be downloaded into many types of software.

raf07034_sediment.xls
raf07034_sediment.txt

Data Dictionary

An integral part of any database is the dictionary that explains its structure and content. The dictionary contains a list of the fields and the definitions of parameters measured. Data utilization is facilitated by reference to this compilation because it defines abbreviations and lists field names.

LABNO - Unique sample identifier assigned in the laboratory

STATIONID - Sample name or number assigned in the field

PROJECTID - Project under which samples were collected or data generated

CRUISEID - Name or number of cruise on which sample was collected or station occupied

PRINCIPAL - Name of Principal Investigator

MONTH - Calendar month sample analyzed

DAY - Calendar day sample analyzed

YEAR - Calendar year sample analyzed

LATITUDE - Latitude in decimal-degrees

LONGITUDE - Longitude in decimal-degrees (west longitudes are negative values)

DEVICE - Device used to collect the sample

AREA - General geographic area

DEPTH_M - Measured depth of water overlying sediment at sample time, not corrected for tides, in meters

T_DEPTH - Top depth of the sample below the sediment-water interface, in centimeters

B_DEPTH - Bottom depth of the sample below the sediment-water interface, in centimeters

WEIGHT - Weight of sample, in grams

ZGRAVEL - Gravel content, in percent dry weight of the sample (particles with nominal diameters greater than 2 millimeters; -1 phi and larger)

ZSAND - Sand content, in percent dry weight of the sample (particles with nominal diameters less than 2 millimeters, but greater than or equal to 0.0625 millimeters; 0 through 4 phi)

ZSILT - Silt content, in percent dry weight of the sample (particles with nominal diameters less than 0.0625 millimeters, but greater than or equal to 0.004 millimeters; 5 through 8 phi, inclusive)

ZCLAY - Clay content, in percent dry weight of the sample (particles with nominal diameters less than 0.004 millimeters; 9 phi and smaller)

SEDCLASS - Sediment description based on a rigorous definition (Shepard, 1954)

MEDIAN - Middle point in the grain-size distribution, in phi units

MEAN - Average value in the grain-size distribution, in phi units

STDDEV - Standard deviation (root mean square of the deviations) of the grain-size distribution, in phi units (that is, sorting)

SKEWNESS - Deviation from symmetrical form of the grain-size distribution, in phi units

KURTOSIS - Degree of curvature near the mode of the grain-size distribution, in phi units

PHI _11 - Weight percent of the sample in the 11-phi fraction (nominal diameter of particles greater than or equal to 0.0005 millimeters, but less than 0.001 millimeters); fine clay

PHI_10 - Weight percent of the sample in the 10-phi fraction (nominal diameter of particles greater than or equal to 0.001 millimeters, but less than 0.002 millimeters); medium clay

PHI_9 - Weight percent of the sample in the 9-phi fraction (nominal diameter of particles greater than or equal to 0.002 millimeters, but less than 0.004 millimeters); coarse clay

PHI_8 - Weight percent of the sample in the 8-phi fraction (nominal diameter of particles greater than or equal to 0.004 millimeters, but less than 0.008 millimeters); very fine silt

PHI_7 - Weight percent of the sample in the 7-phi fraction (nominal diameter of particles greater than or equal to 0.008 millimeters, but less than 0.016 millimeters); fine silt

PHI_6 - Weight percent of the sample in the 6-phi fraction (nominal diameter of particles greater than or equal to 0.016 millimeters, but less than 0.031 millimeters); medium silt

PHI_5 - Weight percent of the sample in the 5-phi fraction (nominal diameter of particles greater than or equal to 0.031 millimeters, but less than 0.0625 millimeters); coarse silt

PHI_4 - Weight percent of the sample in the 4-phi fraction (nominal diameters of particles greater than or equal to .0625 millimeters, but less than 0.125 millimeters); very fine sand

PHI_3 - Weight percent of the sample in the 3-phi fraction (nominal diameter of particles greater than or equal to 0.125 millimeters, but less than 0.25 millimeters); fine sand

PHI_2 - Weight percent of the sample in the 2-phi fraction (nominal diameter of particles greater than or equal to 0.25 millimeters, but less than 0.5 millimeters); medium sand

PHI_1 - Weight percent of the sample in the 1-phi fraction (nominal diameter of particles greater than or equal to 0.5 millimeters, but less than 1 millimeter); coarse sand

PHI_0 - Weight percent of the sample in the 0-phi fraction (nominal diameters of particles greater than or equal to 1 millimeter, but less than 2 millimeters); very coarse sand

PHIM1 - Weight percent of the sample in the -1-phi fraction (nominal diameter of particles greater than or equal to 2 millimeters, but less than 4 millimeters); very fine pebbles (granules)

PHIM2 - Weight percent of the sample in the -2-phi fraction (nominal diameter of particles greater than or equal to 4 millimeters, but less than 8 millimeters); fine pebbles

PHIM3 - Weight percent of the sample in the -3-phi fraction (nominal diameter of particles greater than or equal to 8 millimeters, but less than 16 millimeters); medium pebbles

PHIM4 - Weight percent of the sample in the -4-phi fraction (nominal diameter of particles greater than or equal to 16 millimeters, but less than 32 millimeters); coarse pebbles

PHIM5 - Weight percent of the sample in the -5-phi fraction (nominal diameter of particles greater than or equal to 32 millimeters; very coarse pebbles to boulders

Click on figures for larger images.

Figure 12. Map showing the locations of stations used to verify the acoustic data with bottom sampling and photography during the November 2007 Rafael 07034 cruise.