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OAS accession Detail for 0278796
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| accessions_id: | 0278796 | archive |
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| Title: | Porewater geochemistry data for sediment samples that were included in the global seep survey conducted via Alvin dives from R/V Atlantis cruise AT15-40 in the Guaymas Basin in 2008 (NCEI Accession 0278796) |
| Abstract: | This dataset contains chemical data collected on Alvin and R/V Atlantis during cruise AT15-40 and deployment AT15-40_Alvin_Dives in the Gulf of California from 2008-12-06 to 2008-12-15. These data include d13C, depth, dissolved inorganic Carbon, methane, and sulfate. The instruments used to collect these data include Alvin tube core, Gas Chromatograph, Ion Chromatograph, and Isotope-ratio Mass Spectrometer. These data were collected by Andreas P. Teske, Barbara J. MacGregor, Christopher S. Martens, and Daniel B. Albert of University of North Carolina at Chapel Hill as part of the "Collaborative Research: Microbial Carbon cycling and its interactions with Sulfur and Nitrogen transformations in Guaymas Basin hydrothermal sediments (Guaymas Basin Interactions)" and "Microbial carbon and sulfur cycling in the hydrothermally altered sediments of Guaymas Basin (Guaymas Basin Vents)" projects. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) submitted these data to NCEI on 2020-08-21. The following is the text of the dataset description provided by BCO-DMO: Porewater geochemistry data for sediment samples that were included in global seep survey Dataset Description: Porewater geochemistry of Guaymas Basin hydrothermal sediments (Southern Spreading segment, 27°00.44N and 111°24.55W, 2000 m water depth) including methane, CO2, and sulfate. During two R/V Atlantis cruises to Guaymas Basin, the association of Beggiatoa mats with hydrothermal seepage and the habitat preferences of various Beggiatoa types were investigated by geochemical and microbiological characterization of sediments underneath Beggiatoa mats in combination with temperature measurements down to 40 cm sediment depth. In particular, temperature profiles and corresponding sulfide, sulfate, dissolved inorganic carbon (DIC), delta 13C-DIC, methane, and delta 13C-methane gradients from mats exhibiting orange-to-white color transitions were examined to elucidate hydrothermal fluid delivery and/or tolerance associated with differently colored Beggiatoa types (McKay et al. 2012) |
| Date received: | 20200821 |
| Start date: | 20081206 |
| End date: | 20081215 |
| Seanames: | Gulf of California |
| West boundary: | -111.409 |
| East boundary: | -111.408 |
| North boundary: | 27.008 |
| South boundary: | 27.006 |
| Observation types: | chemical |
| Instrument types: | chromatograph, mass spectrometer |
| Datatypes: | DELTA CARBON-13, DEPTH - OBSERVATION, DISSOLVED INORGANIC CARBON (DIC), Methane (CH4), Sulfate (SO4 2-) |
| Submitter: | |
| Submitting institution: | Biological and Chemical Oceanography Data Management Office |
| Collecting institutions: | University of North Carolina - Chapel Hill |
| Contributing projects: | |
| Platforms: | Alvin (31A5), Atlantis (33AT) |
| Number of observations: | |
| Supplementary information: | Acquisition Description: Temperature profiling: Temperature profiles at the sampling site were recorded using Alvin ’s external heatflow temperature probe, a 0.6 m titanium tube containing a linear heater and five thermistors (type 44032, Omega Engineering, Inc.) at 10 cm intervals along the length of the tube (McKay et al., 2012). When fully immersed in the sediment, this probe records five in-situ temperatures at the sediment/water interface, and at 10, 20, 30 and 40 cm sediment depth. Geochemical Analyses: Sulfate concentration measurements were completed shipboard; after centrifuging sediment-filled 15 ml tubes, the overlying porewater was filtered through 0.45 um filters, acidified with 50 ul of 50% HCl and bubbled with nitrogen for 4 minutes to remove sulfide. Sulfate concentrations were then measured shipboard using a 2010i Dionex Ion Chromatograph (Sunnyvale, CA, USA) through Ag exchange columns (Dionex) so as to remove Cl (Martens et al., 1999). For sulfide, 1 ml porewater samples were combined with 0.1M zinc acetate and concentrations were analyzed spectrophotometrically on the ship (Cline 1969). Headspace methane concentrations were determined onboard by standard gas chromatography with a flame ionization detector (FID), specifically using a HACH Carle Series 100 AGC Gas Chromatograph with a Alltech Molecular Sieve 5A packed column (80/100 mesh, 3.05 m length, 3.2 mm ID) and a 80 degree C isothermal temperature profile. Stable isotopic compositions of the same methane samples (core 4484-3) were measured post-cruise at UNC via gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) on a Finnigan MAT 252 Isotope Ratio Mass Spectrometer, using a HP 5890 Series II Gas Chromatograph with a HP Plot Q column (30 m length, 0.32 mm ID, 20 um film thickness) and a 30 degree C isothermal temperature profile. To measure DIC, 2 ml of unamended porewater from each sediment horizon were injected into evacuated serum vials (30 ml) and stored upside down at -20 degrees C. At UNC, the samples were thawed, and DIC was reacted to gaseous CO2 by adding 1 ml of a 30% phosphoric acid solution to each serum vial and shaking vigorously before GC analysis (Kelley et al., 1990). Stable isotopic values and concentrations of DIC were analyzed via coupled GC (Hewlett Packard 5890) and Isotope Ratio Mass Spectrometer (Finnigan MAT 252). |
| Availability date: | |
| Metadata version: | 1 |
| Keydate: | 2023-05-27 04:16:02+00 |
| Editdate: | 2023-05-27 04:16:39+00 |