http://lod.bco-dmo.org/id/dataset/904417 eng; USA utf8 dataset Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact 2023-07-18 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) Depth profiles of pore water constituents from sediment cores collected on the Louisiana Shelf of the Northern Gulf of Mexico during 2020, 2021, and 2022 on R/V Savannah cruises SAV-20-07, SAV-21-25, SAV-21-24, SAV-22-06, and SAV-22-11 2025-07-16 publication 2025-07-16 revision Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA) 2024-07-02 publication https://doi.org/10.26008/1912/bco-dmo.904417.1 Martial Taillefert Georgia Institute of Technology principalInvestigator Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. publisher Cite this dataset as: Taillefert, M. (2025) Depth profiles of pore water constituents from sediment cores collected on the Louisiana Shelf of the Northern Gulf of Mexico during 2020, 2021, and 2022 on R/V Savannah cruises SAV-20-07, SAV-21-25, SAV-21-24, SAV-22-06, and SAV-22-11. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 2) Version Date 2025-07-16 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.904417.2 [access date] Northern Gulf of Mexico pore water geochemical data Dataset Description: &lt;p&gt;&lt;strong&gt;2020 data:&lt;/strong&gt;&lt;br /&gt; These pore water data were obtained from sediment cores collected at five different stations on the Louisiana Shelf on the Northern Gulf of Mexico during the week of November 3-6, 2020 using an MC-800 multi-corer. These stations extend from the middle of the shelf offshore from Cocodrie, LA to the mouth of the Mississippi River North West Pass. All cores were processed within a few hours after collection. The field sampling was conducted during R/V Savannah cruise SAV-20-07.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;2021 and 2022 data:&lt;/strong&gt;&lt;br /&gt; In July 2021, the pore water data were obtained from sediment cores collected with a MC-800 multi-corer at ten different stations on the Louisiana Shelf and slope in the Northern Gulf of Mexico during July 16-26, 2021. These stations span two transects, one from the middle of the shelf offshore from Cocodrie, LA to the mouth of the Mississippi River's South West Pass, and another one from North West Pass of the Mississippi River mouth to the south, across the slope. A single station (St. 15) was also sampled on the eastern side of the second transect in the transition from the shelf break to the mid-slope.&lt;/p&gt; &lt;p&gt;In October 2021, the pore water data were obtained from sediment cores collected with a MC-800 multi-corer at twelve different stations on the Louisiana Shelf and slope in the Northern Gulf of Mexico between October 25 and November 10, 2021. These stations extend from the middle of the shelf offshore from Cocodrie, LA to the mouth of the Mississippi River's South West Pass. Two stations (St. 15 and St. 12) were also sampled on a second transect from the shelf break to the slope southeast of the Bird's Foot.&lt;/p&gt; &lt;p&gt;In spring 2022, the pore water data were obtained from sediment cores collected with a MC-800 multi-corer at ten different stations on the Louisiana Shelf and slope in the Northern Gulf of Mexico during April 9-20, 2021. These stations span two transects, one from the middle of the shelf offshore from Cocodrie, LA to the mouth of the Mississippi River's South West Pass, and another from South West Pass of the Mississippi River mouth to the south, across the slope. Two stations (St. 15 and St. 12) were also sampled on a second transect from the shelf break to the slope southeast of the Bird's Foot.&lt;/p&gt; &lt;p&gt;In summer 2022, the pore water data were obtained from sediment cores collected with a MC-800 multi-corer at eleven different stations on the Louisiana Shelf and slope in the Northern Gulf of Mexico during July 9 -23, 2022. These stations span two transects, one from the middle of the shelf offshore from Cocodrie, LA to the mouth of the Mississippi River's South West Pass, and another from South West Pass of the Mississippi River mouth to the south, across the slope. Two stations (St. 15 and St. 12) were also sampled on a second transect from the shelf break to the slope southeast of the Bird's Foot.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;All data:&lt;/strong&gt;&lt;br /&gt; The pore waters were first extracted by slicing sediment cores of &amp;lt; 25 centimeters (cm) long and centrifugation of the pore waters under N2 atmosphere to avoid air contamination. Pore waters were then immediately filtered through 0.22-micrometer (um) PSE syringe filters under N2 atmosphere and either analyzed immediately onboard (Fe speciation, orthophosphate, DIC), preserved acidified with hydrochloric acid at 4 degrees Celsius (Cad, Mnd), frozen (ammonium), or preserved at 4 degrees Celsius after addition of HgCl2 (TA) until analysis. In addition, samples for TA and carbon isotopic analyses were preserved in glass bottles, whereas other samples were preserved in polypropylene containers. DIC was analyzed by flow injection analysis (Hall and Aller, 1992), orthophosphate, ammonium, and Fe speciation by spectrophotometry (Murphy and Riley, 1962; Strickland and Parsons, 1972; Stookey, 1970), TA by Gran titration (Gran, 1952), the carbon isotopic signature by isotope ratio mass spectrometry (Wang et al, 2018), and Mnd and Cad by ICP-MS (Magette et al., 2025 In preparation).&lt;/p&gt; Methods and Sampling: &lt;p&gt;Sediments were collected and pore waters were extracted within 30 minutes after sampling. Pore waters were obtained by centrifugation at 3000 rotations per minute (rpm) for less than 10 minutes after slicing the cores in a sealed anaerobic two-hands bag flushed three times with UHP N2 gas. Pore waters were immediately filtered onto 0.22-micrometer (µm) Whatman 25-millimeter (mm) Acrodisc syringe filters (PES membrane) and either preserved until analysis or analyzed immediately onboard the ship. Samples were preserved at 4° Celsius after acidification (dissolved Ca, dissolved Mn, NH4+) or addition of HgCl2 (δ13C-DIC, TA), dispensed directly into reagents for analysis (Fe(II), total dissolved Fe, ΣPO43-), or analyzed immediately (DIC). Sealed borosilicate glass vials were used for TA and δ13C-DIC as recommended (Dickson et al., 2007; Wang et al., 2018).&lt;/p&gt; &lt;p&gt;NH4+ was measured spectrophotometrically by the indophenol blue method (Strickland and Parsons, 1972), total dissolved Fe and Fe(II) were measured spectrophotometrically by the ferrozine method after the addition or not of hydroxylamine (Stookey, 1970). ΣPO43- was measured spectrophotometrically using the molybdate-blue method after natural color correction to avoid interferences from dissolved silica and sulfides (Murphy and Riley, 1962).&lt;/p&gt; &lt;p&gt;For the 2020 data, DIC was measured by flow injection analysis with conductivity detection after spiking samples with 10 millimoles (mM) ZnCl2 to prevent dissolved sulfide interferences (Hall and Aller, 1992). TA was measured by acid titration in an open-cell with continuous pH measurements (Dickson et al., 2007; Rassmann et al., 2016).&lt;/p&gt; &lt;p&gt;For the 2021 and 2022 data, DIC was measured by flow injection analysis with conductivity detection (Hall and Aller, 1992) after spiking samples with 10 mM Na2MoO4 to prevent dissolved sulfide interferences (Lustwerk and Burdige, 1995), except in July 2022 when DIC was measured by cavity ring-down spectrometry (CRDS, Picarro G2131-i) with an automatic CO2 extraction system (Apollo SciTech AS-D1).&lt;/p&gt; &lt;p&gt;δ13C-DIC was measured using an isotope ratio mass spectrometer with high-performance liquid chromatography preparation module for gas samples (Brandes, 2009; Wang et al., 2018). Finally, dissolved Ca and dissolved Mn were measured by ICP-MS with collision cell to prevent argon interferences. Internal standards were used to correct for the drift of the instrument, quality control blanks, standard checks, and certified seawater references were run several times during each run to control accuracy and reproducibility. All calibrations were conducted with at least five standards prepared in a 0.54 molar (M) NaCl matrix prior to each series of measurements. Blanks and quality control checks were run routinely during each analysis. Finally, calibration sensitivities were compared routinely to ensure accuracy of the methods. For DIC analyses, Dickson DIC-certified seawater samples were run routinely during analyses to validate the accuracy of the method. Errors of all reported concentrations represent the analytical error propagated from calibration curves, dilution, and instrumental drift.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Instruments:&lt;/strong&gt;&lt;br /&gt; Sediment cores were collected with an MC-800 multi-corer (Ocean Instruments). Core barrels of 10 cm inner diameter and 75 cm long were used to collect sediments. Aldrich two-glove atmospheric bags were used to control the atmosphere during pore water extraction and centrifugation with an ELMI CM-7S clinical centrifuge.&lt;/p&gt; &lt;p&gt;All spectrophotometric measurements were conducted with a Beckman Coulter DU 720 UV-vis spectrophotometer.&lt;/p&gt; &lt;p&gt;DIC measurements were conducted with an in-house system consisting of a Dynamax peristaltic pump, Rheodyne injection valve, Amber Science conductivity detector, and Analytical Instruments, Inc. LCC-100 integrator with computer control. In July 2022, DIC was measured with a Picarro G2131-i cavity ring-down spectrometry and an Apollo SciTech AS-D1 automatic CO2 extraction system.&lt;/p&gt; &lt;p&gt;TA measurements were obtained with a computer-controlled Metrohm 877 Titrino plus.&lt;/p&gt; &lt;p&gt;δ13C-DIC measurements were conducted with a Thermo Electron SurveyorLite autosampler, a Surveyor MS HPLC pump, and a LC Isolink interface coupled to a Thermo Scientific Delta V plus stable isotope mass spectrometer.&lt;/p&gt; &lt;p&gt;Finally, Cad and Mnd measurements were conducted with an Agilent 7900e ICP-MS with SPS4 Autosampler.&lt;/p&gt; &lt;p&gt;All data provided have been analytically validated via the procedures described above.&lt;/p&gt; Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-1948914 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=1948914 completed Martial Taillefert Georgia Institute of Technology 404-894-6043 School of Earth and Atmospheric Sciences 311 Ferst Dr. NE Atlanta GA 30332 USA mtaillef@eas.gatech.edu pointOfContact asNeeded Dataset Version: 2 Unknown Year Month Day Date Collection_Type Station Lon Lat sample_ID Sediment_depth_cm DIC sd_DIC PO4 sd_PO4 NH4 sd_NH4 TA sd_TA d13C_DIC sd_d13C_DIC Mnd sd_Mnd Cad sd_Cad Fe_II sd_Fe_II Fed sd_Fed Fe_III_d sd_Fe_III_d Apollo SciTech AS-D1 ELMI CM-7S centrifuge Agilent 7900e ICP-MS ICP-MS Thermo Scientific Delta V plus stable isotope mass spectrometer Thermo Electron SurveyorLite autosampler SPS4 Autosampler MC-800 multi-corer Picarro G2131-i cavity ring-down spectrometry Beckman Coulter DU 720 UV-vis spectrophotometer Metrohm 877 Titrino plus theme None, User defined year month of year day of month date sample description station longitude latitude sample identification depth core dissolved inorganic Carbon reactive phosphorus (PO4) Ammonium total alkalinity (TA) 13C to 12C ratio in DIC Manganese Calcium Iron featureType BCO-DMO Standard Parameters Apollo AS-D1 DIC and d13C-DIC Analyzer Centrifuge Inductively Coupled Plasma Mass Spectrometer Inductively Coupled Plasma Mass Spectrometer Isotope-ratio Mass Spectrometer Laboratory Autosampler Laboratory Autosampler Multi Corer Spectrometer Spectrometer Titrator instrument BCO-DMO Standard Instruments SAV-20-07 SAV-21-15 SAV-21-24 SAV-22-06 SAV-22-11 service Deployment Activity Louisiana Shelf, Northern Gulf of Mexico place Locations otherRestrictions otherRestrictions Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use. Importance of Riverine Discharge on the Benthic Flux of Alkalinity to Continental Margins https://osprey.bco-dmo.org/project/894879 Importance of Riverine Discharge on the Benthic Flux of Alkalinity to Continental Margins <p><em><strong>NSF Award Abstract</strong></em><br /> Ocean acidification is the process that lowers the pH of the ocean over time due to uptake of atmospheric carbon dioxide. This project investigates how chemical reactions in marine sediments exposed to high riverine sediment loads influence ocean acidification in coastal waters. Although we know that ocean acidification affects marine life and commercial fisheries in coastal waters, little is known about how acidification processes in the water column are influenced by reactions occurring in sediments on the sea floor. The role of large sediment deposits from rivers in these processes has also never been investigated. This study will be conducted in the Mississippi River and Gulf of Mexico. The Mississippi River transports a high sediment load to the continental shelf in the Gulf of Mexico and plays an important role in the economy of the southern coast of the United States. Results from this study will be useful to the oceanographic community for increasing understanding of ocean acidification processes in delta and shelf environments. It will also benefit decision makers interested in predicting the role of sediments on the nutrient -rich Louisiana shelf for discharge control purposes. This project also has an important educational component by training undergraduate, graduate, and postdoctoral students, providing experiences at sea for undergraduates, and conducting outreach activities with K-12 students.</p> <p>The geochemical and microbiological processes responsible for the transformation of particles deposited on the seafloor will be characterized near the Mississippi River mouth and along the nearby continental slope. The release of acids (CO2) and bases (alkalinity) from the sediment will be quantified using autonomous instruments deployed on the seafloor to determine whether sediments contribute to the acidity of the surrounding water column or instead provide bases to buffer the water column from atmospheric CO2 inputs. As the Mississippi River discharge during the later Winter and Spring provides much more sediment to the coastal zone compared to the rest of the year, research cruises will be taken twice a year to determine how seasonal variations in riverine discharge affect the release of acids and bases into the water column. Mathematical models will then be used to predict the effect of seasonal variations on acids or bases release to the water column. This study will therefore provide a quantitative understanding of the role of large sediment depositions to the seafloor on sediment geochemical and microbiological processes and their feedback to the overlying waters. Simultaneously, a large data set will be generated and used to calibrate mathematical models and better characterize benthic-pelagic interactions. Such efforts are needed to predict how continental margins respond to constantly increasing stress from anthropogenic activities.</p> <p>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.</p> NGoM Benthic Alk Flux largerWorkCitation project eng; USA oceans Louisiana Shelf, Northern Gulf of Mexico -91.337123 -88.605316666667 28.199167 28.94785 2020-11-03 2022-07-21 0 BCO-DMO catalogue of parameters from Depth profiles of pore water constituents from sediment cores collected on the Louisiana Shelf of the Northern Gulf of Mexico during 2020, 2021, and 2022 on R/V Savannah cruises SAV-20-07, SAV-21-25, SAV-21-24, SAV-22-06, and SAV-22-11 Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact http://lod.bco-dmo.org/id/dataset-parameter/904676.rdf Name: Year Units: unitless Description: <p>4-digit year when samples were collected</p> http://lod.bco-dmo.org/id/dataset-parameter/904677.rdf Name: Month Units: unitless Description: <p>Month when samples were collected</p> http://lod.bco-dmo.org/id/dataset-parameter/904678.rdf Name: Day Units: unitless Description: <p>Day of month when samples were collected</p> http://lod.bco-dmo.org/id/dataset-parameter/904679.rdf Name: Date Units: unitless Description: <p>Date when samples were collected</p> http://lod.bco-dmo.org/id/dataset-parameter/904680.rdf Name: Collection_Type Units: unitless Description: <p>Type of sample collection (porewater)</p> http://lod.bco-dmo.org/id/dataset-parameter/904681.rdf Name: Station Units: unitless Description: <p>Station identifier</p> http://lod.bco-dmo.org/id/dataset-parameter/904682.rdf Name: Lon Units: decimal degrees Description: <p>Longitude where samples were collected; negative values = West</p> http://lod.bco-dmo.org/id/dataset-parameter/904683.rdf Name: Lat Units: decimal degrees Description: <p>Latitude where samples were collected; positive values = North</p> http://lod.bco-dmo.org/id/dataset-parameter/904684.rdf Name: sample_ID Units: unitless Description: <p>Sample ID number</p> http://lod.bco-dmo.org/id/dataset-parameter/904685.rdf Name: Sediment_depth_cm Units: centimeters (cm) Description: <p>Sediment depth</p> http://lod.bco-dmo.org/id/dataset-parameter/904686.rdf Name: DIC Units: millimoles per liter (mM) Description: <p>Dissolved inorganic carbon (DIC)</p> http://lod.bco-dmo.org/id/dataset-parameter/904687.rdf Name: sd_DIC Units: millimoles per liter (mM) Description: <p>Standard deviation of DIC</p> http://lod.bco-dmo.org/id/dataset-parameter/904688.rdf Name: PO4 Units: micromoles per liter (uM) Description: <p>Orthophosphate (PO4)</p> http://lod.bco-dmo.org/id/dataset-parameter/904689.rdf Name: sd_PO4 Units: micromoles per liter (uM) Description: <p>Standard deviation of PO4</p> http://lod.bco-dmo.org/id/dataset-parameter/904690.rdf Name: NH4 Units: micromoles per liter (uM) Description: <p>Ammonium (NH4)</p> http://lod.bco-dmo.org/id/dataset-parameter/904691.rdf Name: sd_NH4 Units: micromoles per liter (uM) Description: <p>Standard deviation of NH4</p> http://lod.bco-dmo.org/id/dataset-parameter/904692.rdf Name: TA Units: millimoles per liter (mM) Description: <p>Total alkalinity (TA)</p> http://lod.bco-dmo.org/id/dataset-parameter/904693.rdf Name: sd_TA Units: millimoles per liter (mM) Description: <p>Standard deviation of TA</p> http://lod.bco-dmo.org/id/dataset-parameter/904694.rdf Name: d13C_DIC Units: per mil (‰) Description: <p>The carbon isotopic fractionation of DIC (d13-DIC)</p> http://lod.bco-dmo.org/id/dataset-parameter/904695.rdf Name: sd_d13C_DIC Units: per mil (‰) Description: <p>Standard deviation of d13C_DIC</p> http://lod.bco-dmo.org/id/dataset-parameter/904696.rdf Name: Mnd Units: micromoles per liter (uM) Description: <p>Dissolved manganese (Mn)</p> http://lod.bco-dmo.org/id/dataset-parameter/904697.rdf Name: sd_Mnd Units: micromoles per liter (uM) Description: <p>Standard deviation of Mnd</p> http://lod.bco-dmo.org/id/dataset-parameter/904698.rdf Name: Cad Units: millimoles per liter (mM) Description: <p>Dissolved calcium (Ca)</p> http://lod.bco-dmo.org/id/dataset-parameter/904699.rdf Name: sd_Cad Units: millimoles per liter (mM) Description: <p>Standard deviation of Cad</p> http://lod.bco-dmo.org/id/dataset-parameter/904700.rdf Name: Fe_II Units: micromoles per liter (uM) Description: <p>Reduced iron (Fe(II))</p> http://lod.bco-dmo.org/id/dataset-parameter/904701.rdf Name: sd_Fe_II Units: micromoles per liter (uM) Description: <p>Standard deviation of Fe_II</p> http://lod.bco-dmo.org/id/dataset-parameter/904702.rdf Name: Fed Units: micromoles per liter (uM) Description: <p>Total dissolved iron (Fe)</p> http://lod.bco-dmo.org/id/dataset-parameter/904703.rdf Name: sd_Fed Units: micromoles per liter (uM) Description: <p>Standard deviation of Fed</p> http://lod.bco-dmo.org/id/dataset-parameter/904704.rdf Name: Fe_III_d Units: micromoles per liter (uM) Description: <p>Dissolved Fe(III); the difference of Fed and Fe_II</p> http://lod.bco-dmo.org/id/dataset-parameter/904705.rdf Name: sd_Fe_III_d Units: micromoles per liter (uM) Description: <p>Standard deviation of Fe_III_d</p> GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact 20415 https://darchive.mblwhoilibrary.org/server/api/core/bitstreams/794b5020-4940-411d-977b-b4b543179fdb/content download https://doi.org/10.26008/1912/bco-dmo.904417.1 download onLine dataset &lt;p&gt;Sediments were collected and pore waters were extracted within 30 minutes after sampling. Pore waters were obtained by centrifugation at 3000 rotations per minute (rpm) for less than 10 minutes after slicing the cores in a sealed anaerobic two-hands bag flushed three times with UHP N2 gas. Pore waters were immediately filtered onto 0.22-micrometer (µm) Whatman 25-millimeter (mm) Acrodisc syringe filters (PES membrane) and either preserved until analysis or analyzed immediately onboard the ship. Samples were preserved at 4° Celsius after acidification (dissolved Ca, dissolved Mn, NH4+) or addition of HgCl2 (δ13C-DIC, TA), dispensed directly into reagents for analysis (Fe(II), total dissolved Fe, ΣPO43-), or analyzed immediately (DIC). Sealed borosilicate glass vials were used for TA and δ13C-DIC as recommended (Dickson et al., 2007; Wang et al., 2018).&lt;/p&gt; &lt;p&gt;NH4+ was measured spectrophotometrically by the indophenol blue method (Strickland and Parsons, 1972), total dissolved Fe and Fe(II) were measured spectrophotometrically by the ferrozine method after the addition or not of hydroxylamine (Stookey, 1970). ΣPO43- was measured spectrophotometrically using the molybdate-blue method after natural color correction to avoid interferences from dissolved silica and sulfides (Murphy and Riley, 1962).&lt;/p&gt; &lt;p&gt;For the 2020 data, DIC was measured by flow injection analysis with conductivity detection after spiking samples with 10 millimoles (mM) ZnCl2 to prevent dissolved sulfide interferences (Hall and Aller, 1992). TA was measured by acid titration in an open-cell with continuous pH measurements (Dickson et al., 2007; Rassmann et al., 2016).&lt;/p&gt; &lt;p&gt;For the 2021 and 2022 data, DIC was measured by flow injection analysis with conductivity detection (Hall and Aller, 1992) after spiking samples with 10 mM Na2MoO4 to prevent dissolved sulfide interferences (Lustwerk and Burdige, 1995), except in July 2022 when DIC was measured by cavity ring-down spectrometry (CRDS, Picarro G2131-i) with an automatic CO2 extraction system (Apollo SciTech AS-D1).&lt;/p&gt; &lt;p&gt;δ13C-DIC was measured using an isotope ratio mass spectrometer with high-performance liquid chromatography preparation module for gas samples (Brandes, 2009; Wang et al., 2018). Finally, dissolved Ca and dissolved Mn were measured by ICP-MS with collision cell to prevent argon interferences. Internal standards were used to correct for the drift of the instrument, quality control blanks, standard checks, and certified seawater references were run several times during each run to control accuracy and reproducibility. All calibrations were conducted with at least five standards prepared in a 0.54 molar (M) NaCl matrix prior to each series of measurements. Blanks and quality control checks were run routinely during each analysis. Finally, calibration sensitivities were compared routinely to ensure accuracy of the methods. For DIC analyses, Dickson DIC-certified seawater samples were run routinely during analyses to validate the accuracy of the method. Errors of all reported concentrations represent the analytical error propagated from calibration curves, dilution, and instrumental drift.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Instruments:&lt;/strong&gt;&lt;br /&gt; Sediment cores were collected with an MC-800 multi-corer (Ocean Instruments). Core barrels of 10 cm inner diameter and 75 cm long were used to collect sediments. Aldrich two-glove atmospheric bags were used to control the atmosphere during pore water extraction and centrifugation with an ELMI CM-7S clinical centrifuge.&lt;/p&gt; &lt;p&gt;All spectrophotometric measurements were conducted with a Beckman Coulter DU 720 UV-vis spectrophotometer.&lt;/p&gt; &lt;p&gt;DIC measurements were conducted with an in-house system consisting of a Dynamax peristaltic pump, Rheodyne injection valve, Amber Science conductivity detector, and Analytical Instruments, Inc. LCC-100 integrator with computer control. In July 2022, DIC was measured with a Picarro G2131-i cavity ring-down spectrometry and an Apollo SciTech AS-D1 automatic CO2 extraction system.&lt;/p&gt; &lt;p&gt;TA measurements were obtained with a computer-controlled Metrohm 877 Titrino plus.&lt;/p&gt; &lt;p&gt;δ13C-DIC measurements were conducted with a Thermo Electron SurveyorLite autosampler, a Surveyor MS HPLC pump, and a LC Isolink interface coupled to a Thermo Scientific Delta V plus stable isotope mass spectrometer.&lt;/p&gt; &lt;p&gt;Finally, Cad and Mnd measurements were conducted with an Agilent 7900e ICP-MS with SPS4 Autosampler.&lt;/p&gt; &lt;p&gt;All data provided have been analytically validated via the procedures described above.&lt;/p&gt; Specified by the Principal Investigator(s) &lt;p&gt;&lt;strong&gt;Data Processing:&lt;/strong&gt;&lt;br /&gt; Spectrophotometric measurements were recorded on paper forms specifically designed for each analysis and digitized to process the data. DIC, TA, δ13C-DIC, and ICP-MS data were acquired by computers. DIC chromatographic data were integrated using Matlab-based software developed in-house (Bristow and Taillefert, 2008). TA, δ13C-DIC, and ICP-MS data were processed through Excel macro spreadsheet routines developed for each of these analyses.&lt;/p&gt; &lt;p&gt;In the data file, standard deviations of either duplicate analyses or analytical error are provided with each parameter.&lt;/p&gt; Specified by the Principal Investigator(s) Version 1: (version date: 2024-07-02) - imported original file named &quot;GOM_Fall2020_PoreWaterData_BCO-DMO.xlsx&quot; into the BCO-DMO system; - added &quot;Date&quot; column from the separate &quot;Year&quot;, &quot;Month&quot;, and &quot;Day&quot; columns; - renamed fields to comply with BCO-DMO naming conventions; - rounded the following columns to 3 decimal places: PO4, NH4, Cad, FeII, FeD, FeIII (and their standard deviations); - named the final file &quot;904417_v1_pore_water_fall2020.csv&quot;. Version 2: (version 2 date: 2025-07-16) - Imported the v1 data file, &quot;904417_v1_pore_water_fall2020.csv&quot;, into the BCO-DMO processing system. - Imported the four original files into the BCO-DMO system (original file names: GOM_Summer2021_PoreWaterData_BCO-DMO.xlsx, GOM_Fall2021_PoreWaterData_BCO-DMO.xlsx, GOM_Spring2022_PoreWaterData_BCO-DMO.xlsx, GOM_Summer2022_PoreWaterData_BCO-DMO.xlsx). - Flagged &quot;nd&quot; and &quot;#N/A&quot; as missing data values; missing data are empty/blank in the final CSV file. - Renamed fields to comply with BCO-DMO naming conventions. - Added &quot;Date&quot; column from the separate &quot;Year&quot;, &quot;Month&quot;, and &quot;Day&quot; columns. - Concatenated all data files into a single data file. - Added columns for the cruise ID and collection time period. - Saved the final file as &quot;904417_v2_pore_water.csv&quot; Specified by BCO-DMO Data Managers asNeeded 7.x-1.1 Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact Apollo SciTech AS-D1 Apollo SciTech AS-D1 PI Supplied Instrument Name: Apollo SciTech AS-D1 PI Supplied Instrument Description:In July 2022, DIC was measured with a Picarro G2131-i cavity ring-down spectrometry and an Apollo SciTech AS-D1 automatic CO2 extraction system. Instrument Name: Apollo AS-D1 DIC and d13C-DIC Analyzer Instrument Short Name:Apollo AS-D1 Instrument Description: The AS-D1 is an instrument designed to prepare natural water samples for Dissolved Inorganic Carbon (DIC) and delta13C analysis and provide the user with the analyses outputs. It has features that are specifically useful for seawater and coastal water samples. The instrument provides the user with DIC values (micromol per kg) and the delta13C content of the DIC (per mille). It consists of a digital syringe pump for delivery of reagent and samples, a mass flow controller to regulate flow rate, a CO2 stripping reactor, and an electronic cooling system to remove moisture. The AS-D1 does not measure the sample but is designed to send the gas to a different analyzer. This second instrument then sends the measurements back to the AS-D1 after analysis. The AS-D1 then calculates the desired DIC and delta13C outputs. This instrument is designed for automatic sampling from multiple bottles. It can be used in laboratories on shore or at sea. The instrument was created to be paired with the Picarro G-2131i Carbon Isotope Analyser, however, other models that measure the isotopic ratio of CO2 may be compatible. The precision is +/- 0.1 % for DIC of seawater and +/- 0.07 % for DIC-delta13C. Sample volume is 1-7 milliliters per analysis, and sample time is under 12 minutes. Additional information from the manufacturer is available at: https://apolloscitech.com/dicdelta.html ELMI CM-7S centrifuge ELMI CM-7S centrifuge PI Supplied Instrument Name: ELMI CM-7S centrifuge PI Supplied Instrument Description:Aldrich two-glove atmospheric bags were used to control the atmosphere during pore water extraction and centrifugation with an ELMI CM-7S clinical centrifuge. Instrument Name: Centrifuge Instrument Short Name: Instrument Description: A machine with a rapidly rotating container that applies centrifugal force to its contents, typically to separate fluids of different densities (e.g., cream from milk) or liquids from solids. Agilent 7900e ICP-MS Agilent 7900e ICP-MS PI Supplied Instrument Name: Agilent 7900e ICP-MS PI Supplied Instrument Description:Dissolved Ca and dissolved Mn measurements were conducted with an Agilent 7900e ICP-MS with SPS4 Autosampler. Instrument Name: Inductively Coupled Plasma Mass Spectrometer Instrument Short Name:ICP Mass Spec Instrument Description: An ICP Mass Spec is an instrument that passes nebulized samples into an inductively-coupled gas plasma (8-10000 K) where they are atomized and ionized. Ions of specific mass-to-charge ratios are quantified in a quadrupole mass spectrometer. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB15/ ICP-MS ICP-MS PI Supplied Instrument Name: ICP-MS Instrument Name: Inductively Coupled Plasma Mass Spectrometer Instrument Short Name:ICP Mass Spec Instrument Description: An ICP Mass Spec is an instrument that passes nebulized samples into an inductively-coupled gas plasma (8-10000 K) where they are atomized and ionized. Ions of specific mass-to-charge ratios are quantified in a quadrupole mass spectrometer. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB15/ Thermo Scientific Delta V plus stable isotope mass spectrometer Thermo Scientific Delta V plus stable isotope mass spectrometer PI Supplied Instrument Name: Thermo Scientific Delta V plus stable isotope mass spectrometer PI Supplied Instrument Description:δ13C-DIC measurements were conducted with a Thermo Electron SurveyorLite autosampler, a Surveyor MS HPLC pump, and a LC Isolink interface coupled to a Thermo Scientific Delta V plus stable isotope mass spectrometer. Instrument Name: Isotope-ratio Mass Spectrometer Instrument Short Name:IR Mass Spec; IRMS Instrument Description: The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer). Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/ Thermo Electron SurveyorLite autosampler Thermo Electron SurveyorLite autosampler PI Supplied Instrument Name: Thermo Electron SurveyorLite autosampler PI Supplied Instrument Description:δ13C-DIC measurements were conducted with a Thermo Electron SurveyorLite autosampler, a Surveyor MS HPLC pump, and a LC Isolink interface coupled to a Thermo Scientific Delta V plus stable isotope mass spectrometer. Instrument Name: Laboratory Autosampler Instrument Short Name: Instrument Description: Laboratory apparatus that automatically introduces one or more samples with a predetermined volume or mass into an analytical instrument. SPS4 Autosampler SPS4 Autosampler PI Supplied Instrument Name: SPS4 Autosampler PI Supplied Instrument Description:Dissolved Ca and dissolved Mn measurements were conducted with an Agilent 7900e ICP-MS with SPS4 Autosampler. Instrument Name: Laboratory Autosampler Instrument Short Name: Instrument Description: Laboratory apparatus that automatically introduces one or more samples with a predetermined volume or mass into an analytical instrument. MC-800 multi-corer MC-800 multi-corer PI Supplied Instrument Name: MC-800 multi-corer PI Supplied Instrument Description:Sediment cores were collected with an MC-800 multi-corer (Ocean Instruments). Core barrels of 10 centimeters (cm) inner diameter and 75 cm long were used to collect sediments. Instrument Name: Multi Corer Instrument Short Name:Multi Corer Instrument Description: The Multi Corer is a benthic coring device used to collect multiple, simultaneous, undisturbed sediment/water samples from the seafloor. Multiple coring tubes with varying sampling capacity depending on tube dimensions are mounted in a frame designed to sample the deep ocean seafloor. For more information, see Barnett et al. (1984) in Oceanologica Acta, 7, pp. 399-408. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/51/ Picarro G2131-i cavity ring-down spectrometry Picarro G2131-i cavity ring-down spectrometry PI Supplied Instrument Name: Picarro G2131-i cavity ring-down spectrometry PI Supplied Instrument Description:In July 2022, DIC was measured with a Picarro G2131-i cavity ring-down spectrometry and an Apollo SciTech AS-D1 automatic CO2 extraction system. Instrument Name: Spectrometer Instrument Short Name:Spectrometer Instrument Description: A spectrometer is an optical instrument used to measure properties of light over a specific portion of the electromagnetic spectrum. Community Standard Description: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0460/ Beckman Coulter DU 720 UV-vis spectrophotometer Beckman Coulter DU 720 UV-vis spectrophotometer PI Supplied Instrument Name: Beckman Coulter DU 720 UV-vis spectrophotometer PI Supplied Instrument Description:All spectrophotometric measurements were conducted with a Beckman Coulter DU 720 UV-vis spectrophotometer. Instrument Name: Spectrometer Instrument Short Name:Spectrometer Instrument Description: A spectrometer is an optical instrument used to measure properties of light over a specific portion of the electromagnetic spectrum. Community Standard Description: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0460/ Metrohm 877 Titrino plus Metrohm 877 Titrino plus PI Supplied Instrument Name: Metrohm 877 Titrino plus PI Supplied Instrument Description:TA measurements were obtained with a computer-controlled Metrohm 877 Titrino plus. Instrument Name: Titrator Instrument Short Name:Titrator Instrument Description: Titrators are instruments that incrementally add quantified aliquots of a reagent to a sample until the end-point of a chemical reaction is reached. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB12/ Cruise: SAV-20-07 SAV-20-07 R/V Savannah Community Standard Description R/V Savannah vessel SAV-20-07 Martial Taillefert Georgia Institute of Technology Cruise: SAV-21-15 SAV-21-15 R/V Savannah Community Standard Description R/V Savannah vessel SAV-21-15 Martial Taillefert Georgia Institute of Technology Cruise: SAV-21-24 SAV-21-24 R/V Savannah Community Standard Description R/V Savannah vessel SAV-21-24 Martial Taillefert Georgia Institute of Technology Cruise: SAV-22-06 SAV-22-06 R/V Savannah Community Standard Description R/V Savannah vessel SAV-22-06 Martial Taillefert Georgia Institute of Technology Cruise: SAV-22-11 SAV-22-11 R/V Savannah Community Standard Description R/V Savannah vessel SAV-22-11 Martial Taillefert Georgia Institute of Technology R/V Savannah Community Standard Description R/V Savannah vessel