The Ocean Archive System searches our original datasets as they were submitted to us, not individual points or profiles. If you want to search and retrieve ocean profiles in a common format, or objectively analyzed fields, your better option may be to use one of our project applications. See: Access Data
OAS accession Detail for 0291428
| << previous | |revision: 1 |
| accessions_id: | 0291428 | archive |
|---|---|
| Title: | Dissolved radium isotope activity around Guaymas Basin from samples collected by CTD and HOV Alvin during R/V Atlantis cruise AT42-05 in November 2018 (NCEI Accession 0291428) |
| Abstract: | This dataset contains data collected on Alvin and R/V Atlantis during cruise AT42-05 and deployment AT42-05_Alvin_Dives in the Gulf of California from 2018-11-18 to 2018-11-28. These data include depth. The instruments used to collect these data include Alvin tube core, CTD profiler, Niskin bottle, and Radium Delayed Coincidence Counter. These data were collected by Richard N. Peterson of Coastal Carolina University as part of the "Validation of a New Geochemical Approach to Constrain Deep Sea Porewater Residence Times and Advection Rates: Applications to Biogeochemical Cycling at Guaymas Basin (Guaymas Basin Ra 224 Approach)" project. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) submitted these data to NCEI on 2019-12-09. The following is the text of the dataset description provided by BCO-DMO: This dataset presents dissolved radium isotope activities around Guaymas Basin Dataset Description: This dataset presents dissolved radium isotope activities around Guaymas Basin. |
| Date received: | 20191209 |
| Start date: | 20181118 |
| End date: | 20181128 |
| Seanames: | Gulf of California |
| West boundary: | -111.411 |
| East boundary: | -111.404 |
| North boundary: | 27.046 |
| South boundary: | 27.006 |
| Observation types: | |
| Instrument types: | CTD, Niskin bottle |
| Datatypes: | DEPTH - OBSERVATION |
| Submitter: | |
| Submitting institution: | Biological and Chemical Oceanography Data Management Office |
| Collecting institutions: | Coastal Carolina University |
| Contributing projects: | |
| Platforms: | Alvin (31A5), Atlantis (33AT) |
| Number of observations: | |
| Supplementary information: | Acquisition Description: Samples for this dataset were separated into different worksheets depending on the sample collection method (worksheets have been combined into one dataset; "Collection_Method" column indicates the source worksheet). "CTD" samples were collected from 20L Niskin bottles associated with CTD casts by slowly ( "Core-top waters" were collected by gravity siphoning water overlying sediment cores that were collected as push cores by HOV Alvin, filtering the samples through 0.45 mm cellulose filters, then slowly ( "Alvin Niskins" were recovered from one or several of the 1.25 L Niskin bottles on Alvin. On the ship, these water samples were drained from the Niskin bottles and slowly ( "Porewater" samples were collected by sectioning sediments cores under an inert (Ar) atmosphere at 4-5 cm intervals into 50 mL centrifuge tubes, centrifuging the samples at 5,000 RPM for 15 minutes, then decanting the supernatant fluids and filtering them through 0.45 mm syringe filters. Effluent samples were measured for volume, then diluted with 1 L Ra-free seawater before being passed slowly ( After passing the water samples over the Mn fibers, the fibers were rinsed with Ra-free fresh water, then dried using a compressed air stream to a suitable humidity (Sun and Torgersen, 1998). The fibers were then counted immediately on a Radium Delayed Coincidence Counter (Moore and Arnold, 1996) for total Ra-224 and Ra-223 activity. The fibers were counted again after 3 weeks to measure the supported Ra-224 activity from any sorbed Th-228 on the fibers. This activity is subtracted from the total Ra-224 activity derived from the initial measurement to compute the excess Ra-224 activity (the activity reported in the dataset). Ra-226 activities were measured by sealing the Mn fibers in air-tight cartridges for ~1 week and measuring the accumulated Rn-222 (daughter product of Ra-226) on a radon emanation line (Peterson et al., 2009). Fibers were then counted an additional time on the Radium Delayed Coincidence Counter after ~1 year from collection for Ra-228 (as the change in Th-228 activity from the 3-week measurement; Moore, 2008). Analytical uncertainties are based on counting statistics (as 1-s standard deviation of the total counts logged, propagated through the activity computations). |
| Availability date: | |
| Metadata version: | 1 |
| Keydate: | 2024-04-20 19:34:52+00 |
| Editdate: | 2024-04-20 19:35:25+00 |