Uranium-thorium disequilibrium in north-east Atlantic waters
International audience In this paper we report and compare the concentrations of 234 Th and 238 U measured in surface and subsurface waters collected in the course of a sampling campaign in the north east Atlantic in June-July 1998. Dissolved 234 Th concentrations in surface waters ranged from 5 to...
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fttriple:oai:gotriple.eu:10670/1.oixxaz 2023-05-15T17:38:19+02:00 Uranium-thorium disequilibrium in north-east Atlantic waters Smith, K. J. León Vintró, L. Mitchell, P. I. Bally du Bois, P. Boust, D. University College Dublin Dublin (UCD) Laboratoire de Radioécologie de Cherbourg-Octeville (LRC) Institut de Radioprotection et de Sûreté Nucléaire (IRSN) 2004-01-01 https://doi.org/10.1016/j.jenvrad.2004.01.006 https://hal-normandie-univ.archives-ouvertes.fr/hal-02433546 en eng HAL CCSD Elsevier hal-02433546 doi:10.1016/j.jenvrad.2004.01.006 10670/1.oixxaz https://hal-normandie-univ.archives-ouvertes.fr/hal-02433546 undefined Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 0265-931X EISSN: 1879-1700 Journal of Environmental Radioactivity Journal of Environmental Radioactivity, Elsevier, 2004, 74 (1-3), pp.199 - 210. ⟨10.1016/j.jenvrad.2004.01.006⟩ Scavenging Disequilibrium Thorium Uranium Residence times Colloids Ultrafiltration envir droit Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2004 fttriple https://doi.org/10.1016/j.jenvrad.2004.01.006 2023-01-22T17:36:13Z International audience In this paper we report and compare the concentrations of 234 Th and 238 U measured in surface and subsurface waters collected in the course of a sampling campaign in the north east Atlantic in June-July 1998. Dissolved 234 Th concentrations in surface waters ranged from 5 to 20 Bq m-3 , showing a large deficiency relative to 238 U concentrations (typically 42 Bq m-3). This disequilibrium is indicative of active 234 Th scavenging from surface waters. Observed 234 Th/ 238 U activity ratios, together with corresponding 234 Th particulate concentrations , were used to calculate mean residence times for 234 Th with respect to scavenging onto particles (s diss) and subsequent removal from surface waters (s part). Residence times in the range 5-30 days were determined for s diss and 4-18 days for s part (n ¼ 14). In addition, ultrafiltration experiments at six stations in the course of the same expedition revealed that in northeast Atlantic surface waters a significant fraction (46 AE 17%; n ¼ 6) of the thorium in the (operationally-defined) dissolved phase (0.45 lm) phase. Thus, the time (s c) for fully dissolved 234 Th to appear in the filter-retained fraction is dependent on the rate of colloidal aggregation. Here, we determined s c values in the range 3-17 days. # Article in Journal/Newspaper North East Atlantic Northeast Atlantic Unknown Journal of Environmental Radioactivity 74 1-3 199 210 |
institution |
Open Polar |
collection |
Unknown |
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language |
English |
topic |
Scavenging Disequilibrium Thorium Uranium Residence times Colloids Ultrafiltration envir droit |
spellingShingle |
Scavenging Disequilibrium Thorium Uranium Residence times Colloids Ultrafiltration envir droit Smith, K. J. León Vintró, L. Mitchell, P. I. Bally du Bois, P. Boust, D. Uranium-thorium disequilibrium in north-east Atlantic waters |
topic_facet |
Scavenging Disequilibrium Thorium Uranium Residence times Colloids Ultrafiltration envir droit |
description |
International audience In this paper we report and compare the concentrations of 234 Th and 238 U measured in surface and subsurface waters collected in the course of a sampling campaign in the north east Atlantic in June-July 1998. Dissolved 234 Th concentrations in surface waters ranged from 5 to 20 Bq m-3 , showing a large deficiency relative to 238 U concentrations (typically 42 Bq m-3). This disequilibrium is indicative of active 234 Th scavenging from surface waters. Observed 234 Th/ 238 U activity ratios, together with corresponding 234 Th particulate concentrations , were used to calculate mean residence times for 234 Th with respect to scavenging onto particles (s diss) and subsequent removal from surface waters (s part). Residence times in the range 5-30 days were determined for s diss and 4-18 days for s part (n ¼ 14). In addition, ultrafiltration experiments at six stations in the course of the same expedition revealed that in northeast Atlantic surface waters a significant fraction (46 AE 17%; n ¼ 6) of the thorium in the (operationally-defined) dissolved phase (0.45 lm) phase. Thus, the time (s c) for fully dissolved 234 Th to appear in the filter-retained fraction is dependent on the rate of colloidal aggregation. Here, we determined s c values in the range 3-17 days. # |
author2 |
University College Dublin Dublin (UCD) Laboratoire de Radioécologie de Cherbourg-Octeville (LRC) Institut de Radioprotection et de Sûreté Nucléaire (IRSN) |
format |
Article in Journal/Newspaper |
author |
Smith, K. J. León Vintró, L. Mitchell, P. I. Bally du Bois, P. Boust, D. |
author_facet |
Smith, K. J. León Vintró, L. Mitchell, P. I. Bally du Bois, P. Boust, D. |
author_sort |
Smith, K. J. |
title |
Uranium-thorium disequilibrium in north-east Atlantic waters |
title_short |
Uranium-thorium disequilibrium in north-east Atlantic waters |
title_full |
Uranium-thorium disequilibrium in north-east Atlantic waters |
title_fullStr |
Uranium-thorium disequilibrium in north-east Atlantic waters |
title_full_unstemmed |
Uranium-thorium disequilibrium in north-east Atlantic waters |
title_sort |
uranium-thorium disequilibrium in north-east atlantic waters |
publisher |
HAL CCSD |
publishDate |
2004 |
url |
https://doi.org/10.1016/j.jenvrad.2004.01.006 https://hal-normandie-univ.archives-ouvertes.fr/hal-02433546 |
genre |
North East Atlantic Northeast Atlantic |
genre_facet |
North East Atlantic Northeast Atlantic |
op_source |
Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 0265-931X EISSN: 1879-1700 Journal of Environmental Radioactivity Journal of Environmental Radioactivity, Elsevier, 2004, 74 (1-3), pp.199 - 210. ⟨10.1016/j.jenvrad.2004.01.006⟩ |
op_relation |
hal-02433546 doi:10.1016/j.jenvrad.2004.01.006 10670/1.oixxaz https://hal-normandie-univ.archives-ouvertes.fr/hal-02433546 |
op_rights |
undefined |
op_doi |
https://doi.org/10.1016/j.jenvrad.2004.01.006 |
container_title |
Journal of Environmental Radioactivity |
container_volume |
74 |
container_issue |
1-3 |
container_start_page |
199 |
op_container_end_page |
210 |
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1766138708163035136 |