http://lod.bco-dmo.org/id/dataset/987617
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
2025-10-20
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Dissolved Th/Pa measurements from CTD Niskin collected depth profiles from a GEOTRACES transect cruise along the Mid-Atlantic Ridge in the North Atlantic (GA13/JC156) during December 2017 to January 2018
2025-10-20
publication
2025-10-20
revision
Woods Hole Oceanographic Institution (WHOI BCO-DMO)
2026-02-11
publication
https://doi.org/10.26008/1912/bco-dmo.987617.1
Christopher T. Hayes
University of Southern Mississippi
principalInvestigator
Neil Redmond
University of Southern Mississippi
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: Hayes, C. T., Redmond, N. (2026) Dissolved Th/Pa measurements from CTD Niskin collected depth profiles from a GEOTRACES transect cruise along the Mid-Atlantic Ridge in the North Atlantic (GA13/JC156) during December 2017 to January 2018. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2025-10-20 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.987617.1 [access date]
GA13 Dissolved Th/Pa Dataset Description: Methods and Sampling: <p><strong><u>Sampling Methods at Sea:</u></strong><br />
The GA13 team followed cookbook methods for sampling from the conventional Niskin rosette. To sample for <sup>230</sup>Th, <sup>232</sup>Th, and <sup>231</sup>Pa, samples were taken from the stainless steel rosette and filtered directly from the Niskin bottle through a 0.45 micron AcroPak 500 filter. Tygon tubing was used to attach the filter to the opening of the Niskin bottle. The samples were collected into 4-liter (L) cubitainers. These cubitainers were then double bagged into plastic bags. These samples will then be shipped back to the lab, and stored until analysis.</p>
<p>Samples were not acidified at sea, but once returned to the lab in Mississippi, the samples were acidified to a pH &lt; 2 with Optima HCl and left to equilibrate at least 3 months before analysis.</p>
<p><strong><u>Analytical Methods:</u></strong><br />
In the on-shore laboratory, seawater samples were weighed to determine sample size, taking into account the weight of the cubitainer and of the added acid. Then, weighed aliquots of the artificial isotope yield monitors Th-229 (10 picograms (pg)) and Pa-233 (~0.8 pg) and 10 milligrams (mg) dissolved Fe were added to each sample. After allowing 1 day for spike equilibration, the pH of each sample was raised to 8-9 by adding ~10-14 milliliters (mL) of concentrated NH4OH (Fisher Scientific OPTIMA grade) which caused iron (oxy)hydroxide precipitates to form. Each sample cubitainer was fitted with a nozzle cap, inverted, and the Fe precipitate was allowed to settle for 2 days. After 2 days, the nozzle caps were opened and the pH~8-9 water was slowly drained, leaving only the iron oxyhydroxide precipitate and 250-500 mL of water. The Fe precipitate was transferred to centrifuge tubes for centrifugation and rinsing with Milli-Q H2O (&gt;18 MΩ) to remove the major seawater ions. The precipitate was then dissolved in 8M HNO3 (Fisher Scientific OPTIMA grade) and transferred to a Teflon beaker for acid digestions. First the nitric sample solution was dried to near dry at 180-200°C. The sample was then taken up in 1-2 mL 8 M HNO3, the beakers capped and the samples refluxed at 180°C for at least 3 hours. The sample was then cooled, uncapped, retaining all sample drops in the beaker, heated again to 180°C for an HF (Optima) addition of 1 mL. This solution was dried at 180°C to a white precipitate that is dissolvable in optima HCl. After total dissolution of the sample, another precipitation of iron (oxy)hydroxide followed and the precipitate was washed with Milli-Q H2O, centrifuged, and dissolved in 8M HCl (Fisher Scientific OPTIMA grade) for a series of anion-exchange chromatography using 6 mL polypropylene columns each containing a 1 mL bed of Bio-rad resin (AG1-X8, 100-200 mesh size) and a 45 μm porous polyethylene frit (Anderson et al., 2012). The final column elutions were dried down at 180-200°C in the presence of 2 drops of concentrated HNO3 (Fisher Scientific OPTIMA grade) and taken up in 1.0 mL of 0.32 M HNO3 (Fisher Scientific OPTIMA grade) for mass spectrometric analysis. Digestions and columns were done in a standard fume hood, but whenever samples were sealed (i.e., no acid fumes) they were handled in a benchtop HEPA-filtered laminar flow hood.</p>
<p>Concentrations of Th-232, Th-230, and Pa-231 were calculated by isotope dilution, relative to the calibrated tracers Th-229 and Pa-233 added at the beginning of sample processing. Analyses were carried out on a Thermo-Finnigan ELEMENT XR Single Collector Magnetic Sector ICP-MS. This model lacks the high-performance Interface pump (Jet Pump Aridus I™), but we did utilize the specially designed sample (Jet) and skimmer (X) cones which increased sensitivity. All measurements were made in low resolution mode (∆m/M≈300), peak jumping in Escan mode across the central 5% of the flat-topped peaks. Measurements were made on a MasCom™ SEM; Th-229, Th-230, Pa-231, and Pa-233 were measured in Counting mode, while the Th-232 signals were large enough that they were measured in Analog mode. Two solutions of SRM129, a natural U standard, were run multiple times throughout each run. One solution was in a concentration range where U-238 and U-235 were both measured in Counting mode, allowing us to determine the mass bias/amu (typical values varied from -0.5%/amu to 0.2%/amu). In the other, more concentrated solution, U-238 was measured in Analog mode and U-235 was measured in Counting mode, yielding a measurement of the Analog/Counting Correction Factor (typical values varied from 0.9 to 1.1). These corrections assume that the mass bias and Analog/Counting Correction Factor measured on U isotopes can be applied to Th and Pa isotope measurements. Each sample measurement was bracketed by measurement of an aliquot of the run solution (0.32 M HNO3), which was used to correct for the instrumental background count rates. Tailing of Th-232 into the minor Th and Pa isotopes was monitored by counting at the half-masses surrounding Th-230 and Pa-231. Tailing corrections were typically small (&lt;0.5% and often negligible).</p>
<p>Water samples were analyzed in batches of 12 to 20 (5 batches total). Procedural blanks were determined by processing 4-5 L of Milli-Q H2O in an acid-cleaned cubitainer acidified to pH ~2 with 6 M HCl (Fisher Scientific OPTIMA grade) as a sample in each batch (n = 10 total procedural blanks). In addition to the procedural blanks, with every batch an aliquot of one of two intercalibrated working standard solutions of Th-232, Th-230, and Pa-231, SW STD 2010-1 referred to by Anderson et al. (2012) and SW STD 2015-1 which has ~6 times lower Th-232 activity, were added to acidified MQ-H2O and treated like a sample. Samples were corrected using the procedural blank analyzed during each batch. Procedural blank, limit of detection and the results of the reference material solutions are reported in the Supplemental File "987617_v1_ga13_dissolved_th_pa_LODs.pdf". The limit of detection (LOD) is the smallest quantity of each isotope in samples that can reliably be detected or that can be statistically distinguished from a procedural blank. The LOD was considered to be 2 standard deviations above the average of the procedural blanks and we have scaled the limit of detection into the equivalent concentration in a 5 liter sample. Our results for SWS2010-1 are within the consensus range from the intercalibration exercise (Anderson et al., 2012). Consensus values for SWS2015-1 have not been yet been coordinated but they agree with the reports of the LDEO lab. A total of 134 samples were collected. Human error during the beginning of the analysis period caused a certain number of batches/elemental fractions to be lost during column chromatography (in the case of Pa-231) or clearly contaminated (in the case of Th-232/Th-230) and this resulted in 34 Pa-231 samples, 12 Th-232 samples and 2 Th-230 samples to be reported as missing data (flag = 9).</p>
Funding provided by United Kingdom Natural Environmental Research Council (NERC) Award Number: NE/N010396/1 Award URL: https://gotw.nerc.ac.uk/list_full.asp?pcode=NE/N010396/1&classtype=
Funding provided by United Kingdom Natural Environmental Research Council (NERC) Award Number: NE/N009525/1 Award URL: https://gotw.nerc.ac.uk/list_full.asp?pcode=NE/N009525/1&classtype=
completed
Christopher T. Hayes
University of Southern Mississippi
228-688-3469
Department of Marine Science 1020 Balch Boulevard
Stennis Space Center
MS
39529
USA
christopher.t.hayes@usm.edu
pointOfContact
Neil Redmond
University of Southern Mississippi
Beach Hall 242 354 Mansfield Road - Unit 1045
Storrs
CT
USA
neil.redmond@uconn.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
Station_ID
Event_ID
Start_Date_UTC
Start_Latitude
Start_Longitude
Rosette_Position
Sample_ID
Sample_Depth
Pa_231_D_CONC_BOTTLE_h01akr
SD1_Pa_231_D_CONC_BOTTLE_h01akr
Flag_Pa_231_D_CONC_BOTTLE_h01akr
Th_230_D_CONC_BOTTLE_iiujzv
SD1_Th_230_D_CONC_BOTTLE_iiujzv
Flag_Th_230_D_CONC_BOTTLE_iiujzv
Th_232_D_CONC_BOTTLE_xpr9pd
SD1_Th_232_D_CONC_BOTTLE_xpr9pd
Flag_Th_232_D_CONC_BOTTLE_xpr9pd
centrifuge
conventional Niskin rosette
Thermo-Finnigan ELEMENT XR Single Collector Magnetic Sector ICP-MS
theme
None, User defined
station
event
date
latitude
longitude
bottle
sample identification
depth
Protactinium-231
quality flag
Thorium-230
Thorium-232
featureType
BCO-DMO Standard Parameters
Centrifuge
Niskin bottle
Thermo Scientific ELEMENT XR high resolution inductively coupled plasma mass spectrometer
instrument
BCO-DMO Standard Instruments
JC156
service
Deployment Activity
Southampton, United Kingdom to Pointe-à-Pitre, Guadeloupe
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.
U.S. GEOTRACES
http://www.geotraces.org/
U.S. GEOTRACES
GEOTRACES is a SCOR sponsored program; and funding for program infrastructure development is provided by the U.S. National Science Foundation.
GEOTRACES gained momentum following a special symposium, S02: Biogeochemical cycling of trace elements and isotopes in the ocean and applications to constrain contemporary marine processes (GEOSECS II), at a 2003 Goldschmidt meeting convened in Japan. The GEOSECS II acronym referred to the Geochemical Ocean Section Studies To determine full water column distributions of selected trace elements and isotopes, including their concentration, chemical speciation, and physical form, along a sufficient number of sections in each ocean basin to establish the principal relationships between these distributions and with more traditional hydrographic parameters;
* To evaluate the sources, sinks, and internal cycling of these species and thereby characterize more completely the physical, chemical and biological processes regulating their distributions, and the sensitivity of these processes to global change; and
* To understand the processes that control the concentrations of geochemical species used for proxies of the past environment, both in the water column and in the substrates that reflect the water column.
GEOTRACES will be global in scope, consisting of ocean sections complemented by regional process studies. Sections and process studies will combine fieldwork, laboratory experiments and modelling. Beyond realizing the scientific objectives identified above, a natural outcome of this work will be to build a community of marine scientists who understand the processes regulating trace element cycles sufficiently well to exploit this knowledge reliably in future interdisciplinary studies.
Expand "Projects" below for information about and data resulting from individual US GEOTRACES research projects.
U.S. GEOTRACES
largerWorkCitation
program
Dissolved Th/Pa from GEOTRACES transect GA13: tracers of hydrothermal scavenging
https://osprey.bco-dmo.org/project/994007
Dissolved Th/Pa from GEOTRACES transect GA13: tracers of hydrothermal scavenging
<p>Hydrothermal activity alters the chemistry of the deep ocean and is important in many different global geochemical budgets. This imprint can be surprisingly long-lived and potentially serves as a source or sink of elements up to 1000s of km from its source. While there is much research about the effects of hydrothermal particles on scavenging, or the adsorption and sinking of elements by marine particles, close to vent sites, much less is known about the regional impact of hydrothermal scavenging. Here, we present dissolved seawater concentrations of 230Th and 231Pa, two elements that help indicate scavenging intensity, for 7 hydrothermal sites in the North Mid-Atlantic Ridge as part of GEOTRACES section GA13. Changes in the distribution of 230Th and 231Pa due to hydrothermal activity were estimated by comparison to historical profiles with similar organic particle flux, dust deposition, and water mass aging, then attributing deviation in concentration profile to hydrothermal influence. We find that hydrothermal depletions of 230Th and 231Pa at our site can be explained by simple dispersal of hydrothermal particles from areas with active venting and dilution of this depleted water as it mixes with seawater. Open questions remain, however, about how the precise timing and scale of vent water dispersal impact concentrations of 230Th and 231Pa off the ridge system. We recommend that future modeling parameterize hydrothermal scavenging by predicting 230Th and 231Pa distributions, and potentially other radiotracers, at sub-degree resolution over the MAR. This would allow basin-scale hydrothermal features to be incorporated into global budgets.</p>
<p> </p>
<p>This description is from the following dissertation:<br />
Redmond, Neil, "THE MOBILITY OF LONG-LIVED RADIOISOTOPES AND THEIR BURIAL IN THE MARINE ENVIRONMENT" (2023). Dissertations. 2161. <a href="https://aquila.usm.edu/dissertations/2161" target="_blank">https://aquila.usm.edu/dissertations/2161</a></p>
GA13 Th Pa
largerWorkCitation
project
eng; USA
oceans
Southampton, United Kingdom to Pointe-à-Pitre, Guadeloupe
-45.118
-31.521
25.93
37.842
2017-12-29
2018-01-27
0
BCO-DMO catalogue of parameters from Dissolved Th/Pa measurements from CTD Niskin collected depth profiles from a GEOTRACES transect cruise along the Mid-Atlantic Ridge in the North Atlantic (GA13/JC156) during December 2017 to January 2018
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/990076.rdf
Name: Station_ID
Units: unitless
Description: <p>Station number</p>
http://lod.bco-dmo.org/id/dataset-parameter/990077.rdf
Name: Event_ID
Units: unitless
Description: <p>Event number</p>
http://lod.bco-dmo.org/id/dataset-parameter/990078.rdf
Name: Start_Date_UTC
Units: unitless
Description: <p>Date at start of sample collection</p>
http://lod.bco-dmo.org/id/dataset-parameter/990079.rdf
Name: Start_Latitude
Units: decimal degrees
Description: <p>Latitude at start of sample collection</p>
http://lod.bco-dmo.org/id/dataset-parameter/990080.rdf
Name: Start_Longitude
Units: decimal degrees
Description: <p>Longitude at start of sample collection</p>
http://lod.bco-dmo.org/id/dataset-parameter/990081.rdf
Name: Rosette_Position
Units: unitless
Description: <p>Rosette position</p>
http://lod.bco-dmo.org/id/dataset-parameter/990082.rdf
Name: Sample_ID
Units: unitless
Description: <p>Sample ID number</p>
http://lod.bco-dmo.org/id/dataset-parameter/990083.rdf
Name: Sample_Depth
Units: meters (m)
Description: <p>Sample depth</p>
http://lod.bco-dmo.org/id/dataset-parameter/990084.rdf
Name: Pa_231_D_CONC_BOTTLE_h01akr
Units: micro-Becquerel per kilogram (uBq/kg)
Description: <p>Concentration (or activity) of dissolved 231Pa</p>
http://lod.bco-dmo.org/id/dataset-parameter/990085.rdf
Name: SD1_Pa_231_D_CONC_BOTTLE_h01akr
Units: micro-Becquerel per kilogram (uBq/kg)
Description: <p>Standard deviation of Pa_231_D_CONC_BOTTLE_h01akr</p>
http://lod.bco-dmo.org/id/dataset-parameter/990086.rdf
Name: Flag_Pa_231_D_CONC_BOTTLE_h01akr
Units: unitless
Description: <p>Quality flag for Pa_231_D_CONC_BOTTLE_h01akr</p>
http://lod.bco-dmo.org/id/dataset-parameter/990087.rdf
Name: Th_230_D_CONC_BOTTLE_iiujzv
Units: micro-Becquerel per kilogram (uBq/kg)
Description: <p>Concentration (or activity) of dissolved 230Th</p>
http://lod.bco-dmo.org/id/dataset-parameter/990088.rdf
Name: SD1_Th_230_D_CONC_BOTTLE_iiujzv
Units: micro-Becquerel per kilogram (uBq/kg)
Description: <p>Standard deviation of Th_230_D_CONC_BOTTLE_iiujzv</p>
http://lod.bco-dmo.org/id/dataset-parameter/990089.rdf
Name: Flag_Th_230_D_CONC_BOTTLE_iiujzv
Units: unitless
Description: <p>Quality flag for Th_230_D_CONC_BOTTLE_iiujzv</p>
http://lod.bco-dmo.org/id/dataset-parameter/990090.rdf
Name: Th_232_D_CONC_BOTTLE_xpr9pd
Units: picomole per kilogram (pmol/kg)
Description: <p>Concentration (or activity) of dissolved 232Th</p>
http://lod.bco-dmo.org/id/dataset-parameter/990091.rdf
Name: SD1_Th_232_D_CONC_BOTTLE_xpr9pd
Units: picomole per kilogram (pmol/kg)
Description: <p>Standard deviation of Th_232_D_CONC_BOTTLE_xpr9pd</p>
http://lod.bco-dmo.org/id/dataset-parameter/990092.rdf
Name: Flag_Th_232_D_CONC_BOTTLE_xpr9pd
Units: unitless
Description: <p>Quality flag for Th_232_D_CONC_BOTTLE_xpr9pd</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.987617.1
download
onLine
dataset
<p><strong><u>Sampling Methods at Sea:</u></strong><br />
The GA13 team followed cookbook methods for sampling from the conventional Niskin rosette. To sample for <sup>230</sup>Th, <sup>232</sup>Th, and <sup>231</sup>Pa, samples were taken from the stainless steel rosette and filtered directly from the Niskin bottle through a 0.45 micron AcroPak 500 filter. Tygon tubing was used to attach the filter to the opening of the Niskin bottle. The samples were collected into 4-liter (L) cubitainers. These cubitainers were then double bagged into plastic bags. These samples will then be shipped back to the lab, and stored until analysis.</p>
<p>Samples were not acidified at sea, but once returned to the lab in Mississippi, the samples were acidified to a pH &lt; 2 with Optima HCl and left to equilibrate at least 3 months before analysis.</p>
<p><strong><u>Analytical Methods:</u></strong><br />
In the on-shore laboratory, seawater samples were weighed to determine sample size, taking into account the weight of the cubitainer and of the added acid. Then, weighed aliquots of the artificial isotope yield monitors Th-229 (10 picograms (pg)) and Pa-233 (~0.8 pg) and 10 milligrams (mg) dissolved Fe were added to each sample. After allowing 1 day for spike equilibration, the pH of each sample was raised to 8-9 by adding ~10-14 milliliters (mL) of concentrated NH4OH (Fisher Scientific OPTIMA grade) which caused iron (oxy)hydroxide precipitates to form. Each sample cubitainer was fitted with a nozzle cap, inverted, and the Fe precipitate was allowed to settle for 2 days. After 2 days, the nozzle caps were opened and the pH~8-9 water was slowly drained, leaving only the iron oxyhydroxide precipitate and 250-500 mL of water. The Fe precipitate was transferred to centrifuge tubes for centrifugation and rinsing with Milli-Q H2O (&gt;18 MΩ) to remove the major seawater ions. The precipitate was then dissolved in 8M HNO3 (Fisher Scientific OPTIMA grade) and transferred to a Teflon beaker for acid digestions. First the nitric sample solution was dried to near dry at 180-200°C. The sample was then taken up in 1-2 mL 8 M HNO3, the beakers capped and the samples refluxed at 180°C for at least 3 hours. The sample was then cooled, uncapped, retaining all sample drops in the beaker, heated again to 180°C for an HF (Optima) addition of 1 mL. This solution was dried at 180°C to a white precipitate that is dissolvable in optima HCl. After total dissolution of the sample, another precipitation of iron (oxy)hydroxide followed and the precipitate was washed with Milli-Q H2O, centrifuged, and dissolved in 8M HCl (Fisher Scientific OPTIMA grade) for a series of anion-exchange chromatography using 6 mL polypropylene columns each containing a 1 mL bed of Bio-rad resin (AG1-X8, 100-200 mesh size) and a 45 μm porous polyethylene frit (Anderson et al., 2012). The final column elutions were dried down at 180-200°C in the presence of 2 drops of concentrated HNO3 (Fisher Scientific OPTIMA grade) and taken up in 1.0 mL of 0.32 M HNO3 (Fisher Scientific OPTIMA grade) for mass spectrometric analysis. Digestions and columns were done in a standard fume hood, but whenever samples were sealed (i.e., no acid fumes) they were handled in a benchtop HEPA-filtered laminar flow hood.</p>
<p>Concentrations of Th-232, Th-230, and Pa-231 were calculated by isotope dilution, relative to the calibrated tracers Th-229 and Pa-233 added at the beginning of sample processing. Analyses were carried out on a Thermo-Finnigan ELEMENT XR Single Collector Magnetic Sector ICP-MS. This model lacks the high-performance Interface pump (Jet Pump Aridus I™), but we did utilize the specially designed sample (Jet) and skimmer (X) cones which increased sensitivity. All measurements were made in low resolution mode (∆m/M≈300), peak jumping in Escan mode across the central 5% of the flat-topped peaks. Measurements were made on a MasCom™ SEM; Th-229, Th-230, Pa-231, and Pa-233 were measured in Counting mode, while the Th-232 signals were large enough that they were measured in Analog mode. Two solutions of SRM129, a natural U standard, were run multiple times throughout each run. One solution was in a concentration range where U-238 and U-235 were both measured in Counting mode, allowing us to determine the mass bias/amu (typical values varied from -0.5%/amu to 0.2%/amu). In the other, more concentrated solution, U-238 was measured in Analog mode and U-235 was measured in Counting mode, yielding a measurement of the Analog/Counting Correction Factor (typical values varied from 0.9 to 1.1). These corrections assume that the mass bias and Analog/Counting Correction Factor measured on U isotopes can be applied to Th and Pa isotope measurements. Each sample measurement was bracketed by measurement of an aliquot of the run solution (0.32 M HNO3), which was used to correct for the instrumental background count rates. Tailing of Th-232 into the minor Th and Pa isotopes was monitored by counting at the half-masses surrounding Th-230 and Pa-231. Tailing corrections were typically small (&lt;0.5% and often negligible).</p>
<p>Water samples were analyzed in batches of 12 to 20 (5 batches total). Procedural blanks were determined by processing 4-5 L of Milli-Q H2O in an acid-cleaned cubitainer acidified to pH ~2 with 6 M HCl (Fisher Scientific OPTIMA grade) as a sample in each batch (n = 10 total procedural blanks). In addition to the procedural blanks, with every batch an aliquot of one of two intercalibrated working standard solutions of Th-232, Th-230, and Pa-231, SW STD 2010-1 referred to by Anderson et al. (2012) and SW STD 2015-1 which has ~6 times lower Th-232 activity, were added to acidified MQ-H2O and treated like a sample. Samples were corrected using the procedural blank analyzed during each batch. Procedural blank, limit of detection and the results of the reference material solutions are reported in the Supplemental File "987617_v1_ga13_dissolved_th_pa_LODs.pdf". The limit of detection (LOD) is the smallest quantity of each isotope in samples that can reliably be detected or that can be statistically distinguished from a procedural blank. The LOD was considered to be 2 standard deviations above the average of the procedural blanks and we have scaled the limit of detection into the equivalent concentration in a 5 liter sample. Our results for SWS2010-1 are within the consensus range from the intercalibration exercise (Anderson et al., 2012). Consensus values for SWS2015-1 have not been yet been coordinated but they agree with the reports of the LDEO lab. A total of 134 samples were collected. Human error during the beginning of the analysis period caused a certain number of batches/elemental fractions to be lost during column chromatography (in the case of Pa-231) or clearly contaminated (in the case of Th-232/Th-230) and this resulted in 34 Pa-231 samples, 12 Th-232 samples and 2 Th-230 samples to be reported as missing data (flag = 9).</p>
Specified by the Principal Investigator(s)
<p><strong><u>Data Processing:</u></strong><br />
The reported errors for radionuclide concentrations represent the propagation of one sigma errors based on the standard isotope ratios collected by ICP-MS, estimated error in the Th-229 or Pa-233 spike concentration, and the blank correction of the individual isotopes.</p>
<p>Analysis of all samples was completed over the course of several years. A correction was made to account for the ingrowth of Th-230 and Pa-231 due to the decay of the natural U-234 and U-235 preserved in the acidified samples during the period of time between sample collection and U-Th/Pa separation during anion exchange chromatography. Thus, the reported Th-230 and Pa-231 concentrations have been corrected to represent their concentrations at the time of sampling. U concentrations in the samples were estimated using the bottle salinity (S) measured from the CTD and the U-Salinity relationship in seawater (Owens et al., 2011), [U] = (0.100 * S – 0.326) ng U (g seawater)-1. We used seawater U-isotopic compositions of U-234/U-238 = 1.1468 activity ratio (Andersen et al., 2010), and U-238/U-235 = 137.824 mole ratio (Weyer et al., 2008), to calculate [U-234] and [U-235] respectively based on [U].</p>
<p>Individual uncertainties for protactinium and thorium were calculated to include contributions from (a) blank correction using the variance of the blanks measured over the course of the analyses, (b) standard error of the ratios of the analysis (typically close to counting statistics) and (c) spike calibration. For protactinium we also included assessment of the correction from the yield correction, mass bias and instrument background. In order to assess the reproducibility of the procedure, repeat analyses were performed on the GEOTRACES 2010-1 and 2015-1 standards. Reproducibility metrics on these standard measurements are reported in the Analytical Methods section.</p>
<p><strong><u>Quality Flags:</u></strong><br />
SeaDataNet quality flags have been assigned to all measured and derived parameters. More information on SeaDataNet quality flags is available from GEOTRACES at <a href="https://www.geotraces.org/geotraces-quality-flag-policy/" target="_blank">https://www.geotraces.org/geotraces-quality-flag-policy/</a> and from SeaDataNet at <a href="https://www.seadatanet.org/Standards/Data-Quality-Control" target="_blank">https://www.seadatanet.org/Standards/Data-Quality-Control</a>. In summary:</p>
<p>0 = no quality control;<br />
1 = good value;<br />
2 = probably good value;<br />
3 = probably bad value;<br />
4 = bad value;<br />
5 = changed value;<br />
6 = value below detection;<br />
7 = value in excess;<br />
8 = interpolated value;<br />
9 = missing value;<br />
A = value phenomenon uncertain.</p>
<p><u><strong>Naming Conventions:</strong></u><br />
Parameter names in the form such as "Th_232_D_CONC_BOTTLE" are adopted based on a recommendation from the GEOTRACES community (https://www.geotraces.org/parameter-naming-conventions/).</p>
<p>"Dissolved" (D) here refers to that which passed through stacked 0.8/0.45 µm Acropak™ 500 filter capsules sampled from conventional Niskin bottles on a CTD rosette. All seawater samples were weighed directly in the on-shore laboratory to determine sample size, taking into account acid during acidification.</p>
<p><u><strong>Units of Measurement:</strong></u><br />
Radionuclide concentrations are given as micro-Becquerel (10e-6 Bq, µBq or micro-Bq) per kilogram water for Th-230 and Pa-231, and picomole (10e-12 mol, pmol) per kilogram water for Th-232. A Becquerel is the SI unit for radioactivity and is defined as 1 disintegration per second. These units are recommended by the GEOTRACES community.</p>
Specified by the Principal Investigator(s)
- Imported original file "JC156_dataTemplate.xlsx" into the BCO-DMO system.
- Flagged "nd" as a missing data value (missing data are empty/blank in the final CSV file).
- Renamed fields to comply with BCO-DMO naming conventions.
- Removed empty/unused columns.
- Converted date field to YYYY-MM-DD format.
- Saved the final file as "987617_v1_ga13_dissolved_th_pa.csv".
- Extracted the table of blank, LOD, etc. information from the original .docx file and saved as a PDF, "987617_v1_ga13_dissolved_th_pa_LODs.pdf".
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
centrifuge
centrifuge
PI Supplied Instrument Name: 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.
conventional Niskin rosette
conventional Niskin rosette
PI Supplied Instrument Name: conventional Niskin rosette Instrument Name: Niskin bottle Instrument Short Name:Niskin bottle Instrument Description: A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc. Community Standard Description: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0412/
Thermo-Finnigan ELEMENT XR Single Collector Magnetic Sector ICP-MS
Thermo-Finnigan ELEMENT XR Single Collector Magnetic Sector ICP-MS
PI Supplied Instrument Name: Thermo-Finnigan ELEMENT XR Single Collector Magnetic Sector ICP-MS PI Supplied Instrument Description:Analyses were carried out on a Thermo-Finnigan ELEMENT XR Single Collector Magnetic Sector ICP-MS. This instrument lacks the high-performance Interface pump (Jet Pump Aridus I™), but we did utilize the specially designed sample (Jet) and skimmer (X) cones, which increased sensitivity. Instrument Name: Thermo Scientific ELEMENT XR high resolution inductively coupled plasma mass spectrometer Instrument Short Name:Element XR HR-ICP-MS Instrument Description: A high-resolution (HR) inductively coupled plasma (ICP) mass spectrometer (MS) composed of a dual mode secondary electron multiplier (SEM) and a Faraday detector. The ELEMENT XR instrument has a dynamic range of 5 x 10^7 to 1 x 10^12 counts per second (cps), and allows simultaneous measurement of elements at concentrations over 1000 ug/g.
Cruise: JC156
JC156
RRS James Cook
Community Standard Description
International Council for the Exploration of the Sea
RRS James Cook
vessel
JC156
Alessandro Tagliabue
University of Liverpool
https://www.bodc.ac.uk/resources/inventories/cruise_inventory/reports/jc156.pdf
Report describing JC156
RRS James Cook
Community Standard Description
International Council for the Exploration of the Sea
RRS James Cook
vessel