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OAS accession Detail for 0278080
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| accessions_id: | 0278080 | archive |
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| Title: | Water-column total Th-234 from R/V Thomas G. Thompson cruise TN303 in the Eastern Tropical Pacific in 2013 (U.S. GEOTRACES EPZT project) (NCEI Accession 0278080) |
| Abstract: | This dataset contains chemical and physical data collected on R/V Thomas G. Thompson during cruise TN303 in the South Pacific Ocean from 2013-10-29 to 2013-12-18. These data include depth and trace metal concentration. The instruments used to collect these data include Niskin bottle, Pump - Surface Underway Ship Intake, and Riso Laboratory Anti-coincidence Beta Counters. These data were collected by Willard S. Moore of University of South Carolina and Kenneth O. Buesseler and Matthew A. Charette of Woods Hole Oceanographic Institution as part of the "U.S. GEOTRACES East Pacific Zonal Transect (U.S. GEOTRACES EPZT)" and "US GEOTRACES Pacific Zonal Transect: Rates of supply, removal and internal cycling of trace elements and isotopes (EPZT TEI Rates)" projects and "U.S. GEOTRACES (U.S. GEOTRACES)" program. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) submitted these data to NCEI on 2020-07-09. The following is the text of the dataset description provided by BCO-DMO: Water-column total Th-234 the 2013 U.S. GEOTRACES EPZT cruise. Dataset Description: Water-column total Th-234 with 4 L method from the 2013 U.S. GEOTRACES EPZT cruise. U-238 from U-salinity relationship was also determined but not reported in this dataset. These data can be made available upon request from the PI and/or dataset contact. Methods are described below. |
| Date received: | 20200709 |
| Start date: | 20131029 |
| End date: | 20131218 |
| Seanames: | South Pacific Ocean |
| West boundary: | -152 |
| East boundary: | -77.376 |
| North boundary: | -10.25 |
| South boundary: | -16 |
| Observation types: | chemical, physical |
| Instrument types: | bottle |
| Datatypes: | DEPTH - OBSERVATION, TRACE METALS |
| Submitter: | |
| Submitting institution: | Biological and Chemical Oceanography Data Management Office |
| Collecting institutions: | University of South Carolina, Woods Hole Oceanographic Institution |
| Contributing projects: | GEOTRACES |
| Platforms: | THOMAS G. THOMPSON (3250) |
| Number of observations: | |
| Supplementary information: | Acquisition Description: Sampling details: Super stations: approximately 28 discrete total Th-234 samples were collected throughout the water column, a minimum of 12 depths were chosen in the upper 1000 m. Full stations: approximately 20 discrete total Th-234 samples were collected throughout the water column, a minimum of 12 depths were chosen in the upper 1000 m. Hemi station: 16 discrete total Th-234 samples were collected from the upper 3000 m. Demi and Shelf stations: 12 discrete total Th-234 samples were collected, at shelf stations depths spanned the entire water column, at demis the upper 1000 m was sampled. The shipboard procedures follow Pike et al. (2005). Thorium-234: Thorium-234 was determined by the widely-adopted 4 L method. Generally, shallow (1000 m) were collected from niskin bottles hung above in situ pumps. Data are decay corrected to the mid-point time between when bottles 1 and 12 were fired for shallow casts, when the messenger was dropped for deep casts, and the time of collection for underway samples. All underway samples were collected directly from the ship’s underway system in the aft ODF wet lab (denoted as bottle 99, cast 0, depth 3 m). All data have been recovery-corrected using the Th-230/Th-229 recovery method (see references below) to account for any loss of sample material during processing. All samples were analyzed using RISO Laboratory Anti-coincidence Beta Counters, using a helium/1% butane mixture. Overall method efficiency was determined by minimizing the percent difference between mean U-238 and Th-234 values for samples from >1000 m to > 500 m from the bottom (45.72 %). Only stations 6 through 16 and 23 through 36 were used to determine method efficiency so as not to include samples with potential coastal or hydrothermal influences. Uranium-238: Value and uncertainty from equation derived in Owens et al. (2011) U-238 (dpm/L) = (Salinity * 0.0786) – 0.315 Salinity was measured on board the ship by the Scripps Ocean Data Facility (ODF). For more information on methods and intercalibration procedures, refer to the GEOTRACES Intercalibration Report (PDF) Supplemental File. |
| Availability date: | |
| Metadata version: | 1 |
| Keydate: | 2023-05-12 04:13:53+00 |
| Editdate: | 2023-05-12 04:14:40+00 |