http://lod.bco-dmo.org/id/dataset/1002509
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
2026-07-13
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Porewater geochemical data from methane seeps in the Astoria Canyon and Hydrate Ridge along the Cascadia Margin collected during R/V Atlantis cruises in 2023 and 2024
2026-09-02
publication
2026-09-02
revision
Woods Hole Oceanographic Institution (WHOI BCO-DMO)
2026-09-02
publication
https://doi.org/10.26008/1912/bco-dmo.1002509.1
Laura L. Lapham
University of Maryland Center for Environmental Science
principalInvestigator
John Pohlman
United States Geological Survey
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: Lapham, L. L., Hildebrand, A., Pohlman, J. (2026) Porewater geochemical data from methane seeps in the Astoria Canyon and Hydrate Ridge along the Cascadia Margin collected during R/V Atlantis cruises in 2023 and 2024. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2026-09-02 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.1002509.1 [access date]
Geochemical data from methane seeps in the Cascadia Margin Dataset Description: Methods and Sampling: <p><strong>Core collection:</strong> Cores were collected via three different methods: a multicorer (MUC), a gravity corer (Gravity), or push cores via the HOV Alvin (HR23) or the ROV Jason (HR24; push). Based on pre-discussed project needs, the core collected was then allocated for a specific purpose and assigned a flux regime based on location. When possible, the overlying water on top of the core was siphoned off for major anions and assigned a number.</p>
<p><strong>Core sectioning and porewater extraction:</strong><br />
HR23: Push core material was sectioned through extrusion out the top at 3 centimeters (cm) resolution, gravity core material was sectioned with a tubing cutter, and MUC cores were sectioned by extrusion, typically at 5 cm resolution. First, (2) 3-milliliter (mL) sediment plugs were taken for CH4/CO2 and (1) 3 mL sediment plug was taken for H2 if the Core Allocation = Radiocarbon. A small scoop of sediment was taken for porosity and placed in a Petri dish. Then, the remaining sediment was placed in Reeburgh squeezers (Reeburgh, 1967) to extract the porewater into acid-washed 60 mL syringes equipped with stopcocks. Porewater was then filtered through 0.45 micrometer (um) polyethersulphone syringe filters.</p>
<p>HR24: Push core material was sectioned through extrusion out the top at 5 cm resolution. (2) 3 mL sediment plugs were taken for CH4/CO2 and a small scoop of sediment was taken for porosity and placed in a Petri dish. Then, the remaining sediment was packed into 60 mL acid-clean centrifuge tubes and a rhizon sampler (Rhizosphere Research Products) was inserted. A vacuum was pulled with an acid-clean 60 mL syringe to extract the porewater.</p>
<p><strong>Sediment/porewater sampling:</strong><br />
CH4, CO2, δ13C–CH4, δ13C-CO2: 10 mL glass serum vials containing 3-6 mL sediment preserved with 5 mL saturated brine were subsampled using the headspace equilibration method following Magen et al. (2014). Briefly, 8 mL of ultra-zero purity air (UZA) was injected into the sediment vial with a plastic syringe equipped with a 22-gauge needle. Vials were shaken and the headspace was mixed for 2 minutes, after which 8 mL of headspace gas sample was removed. Check standards for concentration were run approximately every 5 samples and corrected as described by Pohlman and others (2021). For samples measured by cavity ring-down spectroscopy, dissolved concentrations were calculated using the following equation:</p>
<p>((pCH4 * 10^-6 * Vg) / (R * T_extraction) + (Vw * pCH4 * 10^-6 * Sol_CH4)) / Vw * 10^6 = [CH4]</p>
<p>Where pCH4 is the headspace concentration of methane in ppm, Vg is the volume of gas sample in mL, R is the gas constant in L-atm/mol-K, T_extraction is the extraction temperature in Kelvin, Vw is the volume of water sample that was extracted in mL, Sol_CH4 is the solubility of methane in mol/L-atm (Wiesenburg &amp; Guinasso, 1979; Yamamoto et al., 1976), and [CH4] is the dissolved concentration of methane in the original natural water sample, in micromoles per liter.</p>
<p>Porosity: Fresh sediment was placed in pre-weighed Petri dishes, sealed, and refrigerated until measurement in the lab. Petri dishes were weighed upon return to shore, then were placed in a drying oven (45 degrees Celsius, 1 week). Petri dishes with dried sediment were weighed again. The difference between the wet and dry sediment is the water weight, and the ratio of the water volume to the total volume is the porosity, assuming a dry bulk density of 2.5.</p>
<p>DIC and δ13C-DIC: 1 mL porewater was injected into a helium-filled 12 mL exetainer vial pre-filled with 1mL 85% phosphoric acid. The stable carbon isotope ratios and concentrations were determined from CO2 by isotope ratio mass spectrometry. Measurements are standardized with lithium carbonate reference material, and isotope ratios are reported in the standard d-notation relative to VPDB.</p>
<p>DOC and δ13C-DOC: 40 mL amber VOA vials containing 1 mL porewater sample acidified to pH 2 with trace metal clean HCl were measured with the wet oxidation method, similarly to the setup detailed in Lalonde et al. (2014). Samples were acidified and sparged to remove inorganic carbon, then reacted with Sodium persulfate as wet oxidation. Data were normalized using two different internal organic standards (precision ± 0.5 ppm for concentrations and 0.2‰ for isotopes).</p>
<p>SO4 and Cl: 2 mL microcentrifuge tubes containing 40 uL porewater sample acidified to pH 2 with 0.1M H3PO4 were diluted (135x) with Milli-Q water prior to analysis. IAPSO certified seawater standards (Ocean Scientific International Ltd.) were used for all samples and precision is ±1.5%.</p>
<p>TOC and δ13C-TOC: Sediment samples from all cruises were dried at 60 degrees Celsius for three days, then ground with a mortar and pestle. For HR23, homogenized sediment was weighed into silver capsules for acid fumigation. Samples were acid fumigated to remove carbonate and dried at 60 degrees Celsius for 2 to 4 hours, then wrapped into tin capsules. For HR24, homogenized sediment was acidified with direct acid application to remove carbonate, then rinsed, dried, and wrapped into tin capsules. Samples were run on an elemental analyzer interfaced with an isotope ratio mass spectrometer. Samples were normalized to an acetanilide, protein, and bass standard calibrated to standards USGS 40 and USGS 41. Stable carbon isotope values are reported in d notation relative to VPDB.</p>
<p>H2S: Porewater sulfide (ΣH2S) was determined by sparging the sample aliquot after acidification with 25 % phosphoric acid, and trapping evolved H2S in sulfide antioxidant buffer (SAOB) solution for measurement with a sulfide-specific electrode. Standards were prepared from a sodium bisulfide stock solution that was titrated with lead nitrate to determine its concentration daily. Also on a daily basis, the stock solution was serially diluted with SAOB solution to produce a five-level calibration.</p>
<p>NH3: Porewater sample was diluted (4-5x) with Milli-Q water prior to analysis. The SM4500-NH3 G-2011 method was used. All reported values were above the 2024 method detection limit (0.009 mg N/L).</p>
<p>PO4: Porewater sample was diluted (2x) with Milli-Q water prior to analysis. The EPA 365.1 Rev 2.0, 1993 method was used. All reported values were above the 2024 method detection limit (0.0034 mg P/L).</p>
<p>NO2+NO3: Porewater sample was diluted (4-5x) with Milli-Q water prior to analysis. The ASTM D-7781-14 method was used. All reported values were above the 2024 method detection limit (0.0009 mg N/L).</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2049517 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2049517
completed
Laura L. Lapham
University of Maryland Center for Environmental Science
PO Box 38
Solomons
MD
20688-0038
USA
lapham@umces.edu
pointOfContact
John Pohlman
United States Geological Survey
jpohlman@usgs.gov
pointOfContact
asNeeded
Dataset Version: 1
Unknown
Cruise
Region
Station
Lat_ddeg
Long_ddeg
Core_Type
Core_retrieval_method
Date_Collected
Dive
Water_depth_m
Top_sed_depth_cm
Bottom_sed_depth_cm
Depth_cm
Sample_ID
Core_ID
Core_Allocation
Flux_Regime_Location_Based
OLW_num
Comments
Frozen_status
CH4_mM
del13C_CH4
CO2_mM
del13C_CO2
Porosity
del13C_DIC
DIC_mM
DOC_mM
del13C_DOC
Sulfate_mM
Chloride_mM
del13C_TOC
Corg_percent_TOC
del15N_TON
Norg_percent_TON
Norg_percent_TN
Corg_percent_TC
del15N_TN
del13C_TC
Hydrogen_nM
pH
Alkalinity_meq_L
H2S_mM
NH3_mgN_L
PO4_mgP_L
NO2_NO3_mgN_L
B_mmol_kg
Ba_mmol_kg
Ca_mmol_kg
Fe_mmol_kg
K_mmol_kg
Mg_mmol_kg
Na_mmol_kg
Si_mmol_kg
Sr_mmol_kg
Costech ECS 4010 elemental analyzer
gravity corer
Thermo Scientific Aquion ion chromatograph
ThermoFinnigan Delta S & Delta V Plus
ThermoFinnigan DELTAplus XL Isotope Ratio Mass Spectrometer
AS40 Autosampler
multicorer
Picarro G2201-i CRDS
push cores
rhizon sampler
GasBench II system
Aurora 1030C
theme
None, User defined
Cruise identifier
region
station
latitude
longitude
sample description
instrument
date
dive_id
depth_w
depth core
sample identification
core id
comments
methane
d13C
carbon dioxide
sediment porosity
13C to 12C ratio in DIC
dissolved inorganic Carbon
dissolved organic Carbon
sulfate
chloride
organic carbon
d15N
percent composition
delta 15N NO3+NO2
hydrogen
pH
total alkalinity (TA)
H2S
Ammonia
phosphate
nitrate plus nitrite
Boron
Barium
Calcium
Iron
potassium
Magnesium
Sodium
Silicon
Strontium
featureType
BCO-DMO Standard Parameters
Costech International Elemental Combustion System (ECS) 4010
Gravity Corer
Ion Chromatograph
Isotope-ratio Mass Spectrometer
Isotope-ratio Mass Spectrometer
Laboratory Autosampler
Multi Corer
Picarro G2201-i isotope analyzer
Push Corer
Sediment Porewater Sampler
Thermo-Fisher Scientific Gas Bench II
Total Organic Carbon Analyzer
instrument
BCO-DMO Standard Instruments
AT50-14
AT50-29
service
Deployment Activity
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.
Collaborative Research: Investigating the source and flux of dissolved organic carbon released from methane seeps to the deep-ocean
https://sites.google.com/umces.edu/thelaphamlab/home/projects/seepdoc
Collaborative Research: Investigating the source and flux of dissolved organic carbon released from methane seeps to the deep-ocean
<p><em>NSF Award Abstract:</em><br />
Dissolved organic carbon (DOC) is a key component of the ocean’s food web and carbon cycle, and carbon exchanged between oceanic DOC and the atmosphere has influenced atmospheric CO2 levels on timescales ranging from recent decades to the geologic past. Production by marine algae in the surface ocean is the largest source of DOC and its effects on the ocean carbon cycle are widely appreciated. However, the contribution of DOC from additional sources such as rivers, hydrothermal vents, and methane seeps and their impact on ocean ecology and chemistry are not well understood. Each source differs in terms of its biological utilization and age, which affects the storage and distribution of DOC among the ocean basins. Methane seeps located along continental margins are particularly significant because they may transfer globally significant quantities of carbon stored below the seafloor as natural gas and gas hydrate to the oceans. This project will investigate the production, flux, composition and potential for biological utilization of DOC at Hydrate Ridge, located offshore Oregon. Hydrate Ridge is a prominent methane seep with massive accumulations of gas hydrate and a node of the Ocean Observatories Initiative telecommunications cabled array on the Juan De Fuca tectonic plate, which provides a continuous stream of real-time regional oceanographic data. We will sample and chemically characterize methane, DOC, and other materials to provide information about where the materials originated (deep vs shallow), how they have been chemically altered, to what extent they may feed deep ocean organisms, or contribute to the long term storage of DOC in the ocean. Experiments and analysis will be conducted using sediment cores and bottom water samples collected using either the remotely operated vehicle Jason or the human occupied vehicle Alvin during a 7-day ocean expedition. Additionally, this project will place osmotically-driven pumps on the seafloor to continuously sample fluids for approximately one year, thereby allowing us to monitor the movement of methane and DOC expelled from the seafloor to the ocean and constrain processes that regulate the release of carbon to the oceans at methane seeps. This project will support one graduate student and several undergraduates from a community college in Maryland and a college located in a lower-income urban center in southeastern Massachusetts. We will disseminate project findings to the public with a series of videos for public TV.</p>
<p>This study will investigate the production, flux and reactivity of methane-derived dissolved organic carbon (DOC) from methane (CH4) seeps at Hydrate Ridge, Offshore Oregon. The study will address four fundamental questions to determine the significance of CH4-derived DOC within the ocean carbon cycle: (1) How much CH4-derived fossil DOC do seeps contribute to the oceans? (2) To what extent is CH4-derived C incorporated into DOC during anaerobic oxidation of CH4? (3) Is seep DOC bioavailable or recalcitrant when released into the deep ocean? (4) How does the flux of DOC to the water column vary over time? We will employ an interdisciplinary strategy that includes in situ sampling, laboratory incubations, and a comprehensive analytical geochemistry program. Data from the Ocean Observatories Initiative Regional Cabled Array at Southern Hydrate Ridge will be used to provide context for field and experimental data. The composition and abundance of organic and inorganic chemical species along with the stable and radiocarbon isotope composition of pore water, bulk sediment, and water column C pools will be used to identify DOC sources and quantify fluxes from cold seeps characterized by a range of advection rates. The centerpiece of the investigation will be a 7-day research cruise to Hydrate Ridge to collect sediments, pore fluids, and water column samples, and deploy OsmoSamplers for continuous time series fluid sampling. The results will form the foundation for estimating the contribution of CH4-derived DOC to the oceanic DOC pool.</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>
seepDOM
largerWorkCitation
project
eng; USA
oceans
-125.148054
-124.601189
44.569804
46.242425
2023-08-13
2024-08-24
Astoria Canyon and Hydrate Ridge
0
BCO-DMO catalogue of parameters from Porewater geochemical data from methane seeps in the Astoria Canyon and Hydrate Ridge along the Cascadia Margin collected during R/V Atlantis cruises in 2023 and 2024
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/1005838.rdf
Name: Cruise
Units: unitless
Description: <p>Cruise ID for sample collection</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005839.rdf
Name: Region
Units: unitless
Description: <p>General sampling location within the Cascadia Margin (Astoria Canyon, Southern Hydrate Ridge, Northern Hydrate Ridge)</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005840.rdf
Name: Station
Units: unitless
Description: <p>Station ID for sample collection</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005841.rdf
Name: Lat_ddeg
Units: decimal degrees
Description: <p>Sample latitude, south is negative</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005843.rdf
Name: Long_ddeg
Units: decimal degrees
Description: <p>Sample longitude, west is negative</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005845.rdf
Name: Core_Type
Units: unitless
Description: <p>Type of core collected. MUC = core collected via multicorer; push = core collected via HOV Alvin or ROV Jason; Gravity = core collected via gravity corer</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005846.rdf
Name: Core_retrieval_method
Units: unitless
Description: <p>How the core was retrieved from the seafloor. Samples were collected via multicorer, gravity corer, (HOV) Alvin, or (ROV) Jason</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005847.rdf
Name: Date_Collected
Units: unitless
Description: <p>Date the sample was collected</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005848.rdf
Name: Dive
Units: unitless
Description: <p>Assigned dive number for Jason (J2-) or Alvin (AL-)</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005849.rdf
Name: Water_depth_m
Units: meters (m)
Description: <p>Depth of the seafloor relative to the sea surface at the sample location</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005850.rdf
Name: Top_sed_depth_cm
Units: centimeters below sea floor (cmbsf)
Description: <p>Top-depth of core sub-section relative to the sediment water interface</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005851.rdf
Name: Bottom_sed_depth_cm
Units: centimeters below sea floor (cmbsf)
Description: <p>Bottom-depth of core sub-section relative to the sediment water interface</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005852.rdf
Name: Depth_cm
Units: centimeters below sea floor (cmbsf)
Description: <p>Mid-depth of core sub-section relative to the sediment water interface</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005853.rdf
Name: Sample_ID
Units: unitless
Description: <p>Sample ID. Sample IDs are numbers given to each sediment sub-sample when collected, and are specific to each individual cruise</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005854.rdf
Name: Core_ID
Units: unitless
Description: <p>Core ID. Core IDs are specific letter and number combinations given to cores when collected, and are specific to each individual cruise</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005855.rdf
Name: Core_Allocation
Units: unitless
Description: <p>Core Allocation. Core allocations were for specific project needs. Geochem = geochemical characterization; Radiocarbon = radiocarbon measurements and associated geochemistry; DOM Bioavailability = used for incubation experiments to assess the bioavailability of the seep-derived DOM; DOM characterization = FTC-IRMS measurements to assess the compounds in the DOM pool; Metabolites = measurements for metabolites in the sediments; 14C-Kun = radiocarbon measurements for a specific team member; DOM characterization/microbes/H2 = core with split allocation for DOM characterization, microbial abundance, and hydrogen measurements</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005856.rdf
Name: Flux_Regime_Location_Based
Units: unitless
Description: <p>Flux regime assigned to the core based off of visual indicators (i.e., presence of microbial mats or bubbles = high flux; clams = low to intermediate flux)</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005857.rdf
Name: OLW_num
Units: unitless
Description: <p>Overlying core water number assigned to the water siphoned off of the core for major anion analysis</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005858.rdf
Name: Comments
Units: unitless
Description: <p>Comments related to the sample collected such as physical appearance</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005859.rdf
Name: Frozen_status
Units: unitless
Description: <p>Frozen status. Whether or not the whole core was frozen prior to sectioning and porewater extraction</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005860.rdf
Name: CH4_mM
Units: millimolar (mM)
Description: <p>Pore water dissolved methane</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005861.rdf
Name: del13C_CH4
Units: per mille (‰)
Description: <p>Bulk stable carbon isotope value of pore water methane relative to Vienna Pee Dee Belemnite (VPDB)</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005862.rdf
Name: CO2_mM
Units: millimolar (mM)
Description: <p>Pore water dissolved carbon dioxide</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005863.rdf
Name: del13C_CO2
Units: per mille (‰)
Description: <p>Bulk stable carbon isotope value of pore water dissolved carbon dioxide relative to Vienna Pee Dee Belemnite (VPDB)</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005864.rdf
Name: Porosity
Units: unitless
Description: <p>Sediment water content relative to solid material</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005865.rdf
Name: del13C_DIC
Units: per mille (‰)
Description: <p>Bulk stable carbon isotope value of pore water dissolved inorganic carbon relative to Vienna Pee Dee Belemnite (VPDB)</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005866.rdf
Name: DIC_mM
Units: millimolar (mM)
Description: <p>Pore water dissolved inorganic carbon</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005867.rdf
Name: DOC_mM
Units: millimolar (mM)
Description: <p>Pore water dissolved organic carbon</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005868.rdf
Name: del13C_DOC
Units: per mille (‰)
Description: <p>Bulk stable carbon isotope value of pore water dissolved organic carbon relative to Vienna Pee Dee Belemnite (VPDB)</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005869.rdf
Name: Sulfate_mM
Units: millimolar (mM)
Description: <p>Pore water dissolved sulfate</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005870.rdf
Name: Chloride_mM
Units: millimolar (mM)
Description: <p>Pore water dissolved chloride</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005871.rdf
Name: del13C_TOC
Units: per mille (‰)
Description: <p>Bulk stable carbon isotope value of sediment total organic carbon content relative to Vienna Pee Dee Belemnite (VPDB)</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005872.rdf
Name: Corg_percent_TOC
Units: weight percent (wt.%)
Description: <p>sediment total organic carbon content</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005873.rdf
Name: del15N_TON
Units: per mille (‰)
Description: <p>Bulk stable nitrogen isotope value of sediment total organic nitrogen content relative to Vienna Pee Dee Belemnite (VPDB)</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005874.rdf
Name: Norg_percent_TON
Units: weight percent (wt.%)
Description: <p>sediment total organic nitrogen content</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005875.rdf
Name: Norg_percent_TN
Units: weight percent (wt.%)
Description: <p>sediment total nitrogen content</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005876.rdf
Name: Corg_percent_TC
Units: weight percent (wt.%)
Description: <p>sediment total carbon content</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005877.rdf
Name: del15N_TN
Units: per mille (‰)
Description: <p>Bulk stable nitrogen isotope value of sediment total nitrogen content relative to Vienna Pee Dee Belemnite (VPDB)</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005878.rdf
Name: del13C_TC
Units: per mille (‰)
Description: <p>Bulk stable carbon isotope value of sediment total carbon content relative to Vienna Pee Dee Belemnite (VPDB)</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005879.rdf
Name: Hydrogen_nM
Units: nanomolar (nM)
Description: <p>Pore water dissolved hydrogen</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005880.rdf
Name: pH
Units: unitless
Description: <p>Porewater dissolved potential of hydrogen</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005881.rdf
Name: Alkalinity_meq_L
Units: milliequivalents per liter
Description: <p>Porewater dissolved alkalinity</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005882.rdf
Name: H2S_mM
Units: millimolar (mM)
Description: <p>Pore water dissolved sulfide</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005883.rdf
Name: NH3_mgN_L
Units: milligrams N per liter
Description: <p>Pore water dissolved ammonia</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005884.rdf
Name: PO4_mgP_L
Units: milligrams P per liter
Description: <p>Pore water dissolved phosphate</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005885.rdf
Name: NO2_NO3_mgN_L
Units: milligrams N per liter
Description: <p>Pore water dissolved nitrite and nitrate</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005886.rdf
Name: B_mmol_kg
Units: millimoles per kilogram
Description: <p>Pore water dissolved boron</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005887.rdf
Name: Ba_mmol_kg
Units: millimoles per kilogram
Description: <p>Pore water dissolved barium</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005888.rdf
Name: Ca_mmol_kg
Units: millimoles per kilogram
Description: <p>Pore water dissolved calcium</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005889.rdf
Name: Fe_mmol_kg
Units: millimoles per kilogram
Description: <p>Pore water dissolved iron</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005890.rdf
Name: K_mmol_kg
Units: millimoles per kilogram
Description: <p>Pore water dissolved potassium</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005891.rdf
Name: Mg_mmol_kg
Units: millimoles per kilogram
Description: <p>Pore water dissolved magnesium</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005892.rdf
Name: Na_mmol_kg
Units: millimoles per kilogram
Description: <p>Pore water dissolved sodium</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005893.rdf
Name: Si_mmol_kg
Units: millimoles per kilogram
Description: <p>Pore water dissolved silicon</p>
http://lod.bco-dmo.org/id/dataset-parameter/1005894.rdf
Name: Sr_mmol_kg
Units: millimoles per kilogram
Description: <p>Pore water dissolved strontium</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
https://doi.org/10.26008/1912/bco-dmo.1002509.1
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onLine
dataset
<p><strong>Core collection:</strong> Cores were collected via three different methods: a multicorer (MUC), a gravity corer (Gravity), or push cores via the HOV Alvin (HR23) or the ROV Jason (HR24; push). Based on pre-discussed project needs, the core collected was then allocated for a specific purpose and assigned a flux regime based on location. When possible, the overlying water on top of the core was siphoned off for major anions and assigned a number.</p>
<p><strong>Core sectioning and porewater extraction:</strong><br />
HR23: Push core material was sectioned through extrusion out the top at 3 centimeters (cm) resolution, gravity core material was sectioned with a tubing cutter, and MUC cores were sectioned by extrusion, typically at 5 cm resolution. First, (2) 3-milliliter (mL) sediment plugs were taken for CH4/CO2 and (1) 3 mL sediment plug was taken for H2 if the Core Allocation = Radiocarbon. A small scoop of sediment was taken for porosity and placed in a Petri dish. Then, the remaining sediment was placed in Reeburgh squeezers (Reeburgh, 1967) to extract the porewater into acid-washed 60 mL syringes equipped with stopcocks. Porewater was then filtered through 0.45 micrometer (um) polyethersulphone syringe filters.</p>
<p>HR24: Push core material was sectioned through extrusion out the top at 5 cm resolution. (2) 3 mL sediment plugs were taken for CH4/CO2 and a small scoop of sediment was taken for porosity and placed in a Petri dish. Then, the remaining sediment was packed into 60 mL acid-clean centrifuge tubes and a rhizon sampler (Rhizosphere Research Products) was inserted. A vacuum was pulled with an acid-clean 60 mL syringe to extract the porewater.</p>
<p><strong>Sediment/porewater sampling:</strong><br />
CH4, CO2, δ13C–CH4, δ13C-CO2: 10 mL glass serum vials containing 3-6 mL sediment preserved with 5 mL saturated brine were subsampled using the headspace equilibration method following Magen et al. (2014). Briefly, 8 mL of ultra-zero purity air (UZA) was injected into the sediment vial with a plastic syringe equipped with a 22-gauge needle. Vials were shaken and the headspace was mixed for 2 minutes, after which 8 mL of headspace gas sample was removed. Check standards for concentration were run approximately every 5 samples and corrected as described by Pohlman and others (2021). For samples measured by cavity ring-down spectroscopy, dissolved concentrations were calculated using the following equation:</p>
<p>((pCH4 * 10^-6 * Vg) / (R * T_extraction) + (Vw * pCH4 * 10^-6 * Sol_CH4)) / Vw * 10^6 = [CH4]</p>
<p>Where pCH4 is the headspace concentration of methane in ppm, Vg is the volume of gas sample in mL, R is the gas constant in L-atm/mol-K, T_extraction is the extraction temperature in Kelvin, Vw is the volume of water sample that was extracted in mL, Sol_CH4 is the solubility of methane in mol/L-atm (Wiesenburg &amp; Guinasso, 1979; Yamamoto et al., 1976), and [CH4] is the dissolved concentration of methane in the original natural water sample, in micromoles per liter.</p>
<p>Porosity: Fresh sediment was placed in pre-weighed Petri dishes, sealed, and refrigerated until measurement in the lab. Petri dishes were weighed upon return to shore, then were placed in a drying oven (45 degrees Celsius, 1 week). Petri dishes with dried sediment were weighed again. The difference between the wet and dry sediment is the water weight, and the ratio of the water volume to the total volume is the porosity, assuming a dry bulk density of 2.5.</p>
<p>DIC and δ13C-DIC: 1 mL porewater was injected into a helium-filled 12 mL exetainer vial pre-filled with 1mL 85% phosphoric acid. The stable carbon isotope ratios and concentrations were determined from CO2 by isotope ratio mass spectrometry. Measurements are standardized with lithium carbonate reference material, and isotope ratios are reported in the standard d-notation relative to VPDB.</p>
<p>DOC and δ13C-DOC: 40 mL amber VOA vials containing 1 mL porewater sample acidified to pH 2 with trace metal clean HCl were measured with the wet oxidation method, similarly to the setup detailed in Lalonde et al. (2014). Samples were acidified and sparged to remove inorganic carbon, then reacted with Sodium persulfate as wet oxidation. Data were normalized using two different internal organic standards (precision ± 0.5 ppm for concentrations and 0.2‰ for isotopes).</p>
<p>SO4 and Cl: 2 mL microcentrifuge tubes containing 40 uL porewater sample acidified to pH 2 with 0.1M H3PO4 were diluted (135x) with Milli-Q water prior to analysis. IAPSO certified seawater standards (Ocean Scientific International Ltd.) were used for all samples and precision is ±1.5%.</p>
<p>TOC and δ13C-TOC: Sediment samples from all cruises were dried at 60 degrees Celsius for three days, then ground with a mortar and pestle. For HR23, homogenized sediment was weighed into silver capsules for acid fumigation. Samples were acid fumigated to remove carbonate and dried at 60 degrees Celsius for 2 to 4 hours, then wrapped into tin capsules. For HR24, homogenized sediment was acidified with direct acid application to remove carbonate, then rinsed, dried, and wrapped into tin capsules. Samples were run on an elemental analyzer interfaced with an isotope ratio mass spectrometer. Samples were normalized to an acetanilide, protein, and bass standard calibrated to standards USGS 40 and USGS 41. Stable carbon isotope values are reported in d notation relative to VPDB.</p>
<p>H2S: Porewater sulfide (ΣH2S) was determined by sparging the sample aliquot after acidification with 25 % phosphoric acid, and trapping evolved H2S in sulfide antioxidant buffer (SAOB) solution for measurement with a sulfide-specific electrode. Standards were prepared from a sodium bisulfide stock solution that was titrated with lead nitrate to determine its concentration daily. Also on a daily basis, the stock solution was serially diluted with SAOB solution to produce a five-level calibration.</p>
<p>NH3: Porewater sample was diluted (4-5x) with Milli-Q water prior to analysis. The SM4500-NH3 G-2011 method was used. All reported values were above the 2024 method detection limit (0.009 mg N/L).</p>
<p>PO4: Porewater sample was diluted (2x) with Milli-Q water prior to analysis. The EPA 365.1 Rev 2.0, 1993 method was used. All reported values were above the 2024 method detection limit (0.0034 mg P/L).</p>
<p>NO2+NO3: Porewater sample was diluted (4-5x) with Milli-Q water prior to analysis. The ASTM D-7781-14 method was used. All reported values were above the 2024 method detection limit (0.0009 mg N/L).</p>
Specified by the Principal Investigator(s)
<p>Methane, carbon dioxide, and dissolved inorganic carbon concentrations and stable carbon isotope ratios: Software for Picarro was used to obtain the CH4, CO2, and DIC concentrations (ppm) as well as stable carbon isotope ratios (delta notation; per mille). Concentrations were converted to dissolved concentrations (mM) and stable carbon isotope ratios were corrected for the machine offset using Microsoft Excel.</p>
<p>Sulfate and chloride: Chromeleon 7 software was used to obtain areas for SO4 and Cl. Areas were converted to concentrations (mM) using Microsoft Excel.</p>
<p>Particulate organic carbon concentrations and stable carbon isotope ratios: EAS Clarity 3.0.0.154 and Isodat Acquisition Version 3.0 were used to obtain POC concentrations (%) and stable carbon isotope ratios (delta notation; per mille). Concentrations and stable carbon isotope ratios were corrected for machine drift using Microsoft Excel.</p>
Specified by the Principal Investigator(s)
- Imported sheet 1 of the original Excel file "HR23_HR24_combined_BCO_DMO_v2.xlsx" into the BCO-DMO data processing system.
- Renamed column OLW_# to OLW_num to comply with BCO-DMO naming conventions.
- Converted Date_Collected column from string format %m-%d-%y to date type with output format %Y-%m-%d.
- Renamed column NO3_mgN_L to NO2_NO3_mgN_L.
- Saved the final file as "1002509_v1_porewater_geochem_hr23_hr24.csv".
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
Costech ECS 4010 elemental analyzer
Costech ECS 4010 elemental analyzer
PI Supplied Instrument Name: Costech ECS 4010 elemental analyzer PI Supplied Instrument Description:Total organic carbon and stable carbon isotopes were measured with a Costech ECS 4010 elemental analyzer equipped with a thermal conduction detector and connected to a continuous flow isotope ratio mass spectrometer Delta V Plus (Thermo Scientific) using He as the carrier gas at Chesapeake Biological Laboratory. Instrument Name: Costech International Elemental Combustion System (ECS) 4010 Instrument Short Name:Costech ECS 4010 Instrument Description: The ECS 4010 Nitrogen / Protein Analyzer is an elemental combustion analyser for CHNSO elemental analysis and Nitrogen / Protein determination. The GC oven and separation column have a temperature range of 30-110 degC, with control of +/- 0.1 degC.
gravity corer
gravity corer
PI Supplied Instrument Name: gravity corer PI Supplied Instrument Description:Cores were collected via three different methods: a multicorer (MUC), a gravity corer (Gravity), or push cores via the HOV Alvin (HR23) or the ROV Jason (HR24; push). Instrument Name: Gravity Corer Instrument Short Name:Gravity Corer Instrument Description: The gravity corer allows researchers to sample sediment layers at the bottom of lakes or oceans. The coring device is deployed from the ship and gravity carries it to the seafloor. From: http://www.whoi.edu/instruments/viewInstrument.do?id=1079 Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/51/
Thermo Scientific Aquion ion chromatograph
Thermo Scientific Aquion ion chromatograph
PI Supplied Instrument Name: Thermo Scientific Aquion ion chromatograph PI Supplied Instrument Description:Sulfate and chloride were measured with a Thermo Scientific Aquion ion chromatograph (IonPac AG22 4x50 mm guard column, IonPac AS22 4x250 mm analytical column, and AERS 300 4 mm suppressor) with an AS40 Autosampler shipboard and at Chesapeake Biological Laboratory. Instrument Name: Ion Chromatograph Instrument Short Name:Ion Chromatograph Instrument Description: Ion chromatography is a form of liquid chromatography that measures concentrations of ionic species by separating them based on their interaction with a resin. Ionic species separate differently depending on species type and size. Ion chromatographs are able to measure concentrations of major anions, such as fluoride, chloride, nitrate, nitrite, and sulfate, as well as major cations such as lithium, sodium, ammonium, potassium, calcium, and magnesium in the parts-per-billion (ppb) range. From: http://serc.carleton.edu/microbelife/research_methods/biogeochemical/ic.html
ThermoFinnigan Delta S & Delta V Plus
ThermoFinnigan Delta S & Delta V Plus
PI Supplied Instrument Name: ThermoFinnigan Delta S & Delta V Plus PI Supplied Instrument Description:DIC concentrations and carbon isotope values measured using a GasBench II system interfaced with a Delta V Plus isotope ratio mass spectrometer at the University of California Davis Stable Isotope Facility. 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/
ThermoFinnigan DELTAplus XL Isotope Ratio Mass Spectrometer
ThermoFinnigan DELTAplus XL Isotope Ratio Mass Spectrometer
PI Supplied Instrument Name: ThermoFinnigan DELTAplus XL Isotope Ratio Mass Spectrometer PI Supplied Instrument Description:DOC and DOC d13C: d13C-DOC values were quantified using a ThermoFinnigan DELTAplus XL Isotope Ratio Mass Spectrometer interfaced to the Aurora 1030C following the method of Lalonde and others (2014). 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/
AS40 Autosampler
AS40 Autosampler
PI Supplied Instrument Name: AS40 Autosampler PI Supplied Instrument Description:Sulfate and chloride were measured with a Thermo Scientific Aquion ion chromatograph (IonPac AG22 4x50 mm guard column, IonPac AS22 4x250 mm analytical column, and AERS 300 4 mm suppressor) with an AS40 Autosampler shipboard and at Chesapeake Biological Laboratory. 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.
multicorer
multicorer
PI Supplied Instrument Name: multicorer PI Supplied Instrument Description:Cores were collected via three different methods: a multicorer (MUC), a gravity corer (Gravity), or push cores via the HOV Alvin (HR23) or the ROV Jason (HR24; push). 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 G2201-i CRDS
Picarro G2201-i CRDS
PI Supplied Instrument Name: Picarro G2201-i CRDS PI Supplied Instrument Description:Dissolved methane and carbon dioxide concentrations and stable carbon isotopes were determined using a Picarro G2201-i CRDS at US Geological Survey. Instrument Name: Picarro G2201-i isotope analyzer Instrument Short Name: Instrument Description: The G2201-i Isotopic Analyzer measures d13C for CH4 and CO2. See: https://www.picarro.com/products/g2201i_isotopic_analyzer
push cores
push cores
PI Supplied Instrument Name: push cores PI Supplied Instrument Description:Cores were collected via three different methods: a multicorer (MUC), a gravity corer (Gravity), or push cores via the HOV Alvin (HR23) or the ROV Jason (HR24; push). Instrument Name: Push Corer Instrument Short Name: Instrument Description: Capable of being performed in numerous environments, push coring is just as it sounds. Push coring is simply pushing the core barrel (often an aluminum or polycarbonate tube) into the sediment by hand. A push core is useful in that it causes very little disturbance to the more delicate upper layers of a sub-aqueous sediment.
Description obtained from: http://web.whoi.edu/coastal-group/about/how-we-work/field-methods/coring/
rhizon sampler
rhizon sampler
PI Supplied Instrument Name: rhizon sampler PI Supplied Instrument Description:rhizon sampler (Rhizosphere Research Products) Instrument Name: Sediment Porewater Sampler Instrument Short Name: Instrument Description: A device that collects samples of pore water from various horizons below the seabed.
GasBench II system
GasBench II system
PI Supplied Instrument Name: GasBench II system PI Supplied Instrument Description:DIC concentrations and carbon isotope values measured using a GasBench II system interfaced with a Delta V Plus isotope ratio mass spectrometer at the University of California Davis Stable Isotope Facility. Instrument Name: Thermo-Fisher Scientific Gas Bench II Instrument Short Name:GasBench II Instrument Description: An on-line gas preparation and introduction system for isotope ratio mass spectrometry that is designed for high precision isotope and molecular ratio determination of headspace samples, including water equilibration, carbonates and atmospheric gases. The instrument allows for the use of a dual viscous flow inlet system of repetitive measurements of sample and standard gas on a continuous flow isotope ratio mass spectrometer (CF-IRMS) system. The sample volume is the sample vial (instead of a metal bellows), and the reference gas volume is a pressurized gas tank. The instrument consists of a user programmable autosampler, a gas sampling system, a maintenance-free water removal system, a loop injection system, an isothermal gas chromatograph (GC), an active open split interface, a reference gas injection system with three reference ports, and one or two optional LN2 traps for cryofocusing. The gas sampling system includes a two port needle which adds a gentle flow of He into the sample vial, diluting and displacing sample gas. Water is removed from the sample gas through diffusion traps. The loop injector aliquots the sample gas onto the GC column, which separates the molecular species. The reference gas injection system allows accurate referencing of each sample aliquot to isotopic standards. The system can be used with several options including a carbonate reaction kit that allows injection of anhydrous phospohric acid into sample vials.
Note "Finnigan GasBench-II" is the previous brand name of this instrument.
Aurora 1030C
Aurora 1030C
PI Supplied Instrument Name: Aurora 1030C PI Supplied Instrument Description:d13C-DOC values were quantified using a ThermoFinnigan DELTAplus XL Isotope Ratio Mass Spectrometer interfaced to the Aurora 1030C following the method of Lalonde and others (2014). Instrument Name: Total Organic Carbon Analyzer Instrument Short Name:TOC analyzer Instrument Description: A unit that accurately determines the carbon concentrations of organic compounds typically by detecting and measuring its combustion product (CO2). See description document at: http://bcodata.whoi.edu/LaurentianGreatLakes_Chemistry/bs116.pdf Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB04/
Cruise: AT50-14
AT50-14
R/V Atlantis
Community Standard Description
International Council for the Exploration of the Sea
R/V Atlantis
vessel
AT50-14
Laura L. Lapham
University of Maryland Center for Environmental Science
Cruise: AT50-29
AT50-29
R/V Atlantis
Community Standard Description
International Council for the Exploration of the Sea
R/V Atlantis
vessel
AT50-29
Michael Vardaro
University of Washington
R/V Atlantis
Community Standard Description
International Council for the Exploration of the Sea
R/V Atlantis
vessel