Quantifying Lithogenic Inputs to the Southern Ocean Using Long-Lived Thorium Isotopes
Thorium (Th) isotopes were applied to quantify the supply of lithogenic inputs from the Kerguelen Plateau to the Southern Ocean. The dissolved concentrations of 232Th and 230Th were measured following a novel pre-concentration method using the Nobias resin from 10 stations above and on the slopes of...
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2020
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Online Access: | https://doi.org/10.3389/fmars.2020.00207 https://doaj.org/article/5e5a260d24804f9b9066d1e1c14d10f2 |
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ftdoajarticles:oai:doaj.org/article:5e5a260d24804f9b9066d1e1c14d10f2 2023-05-15T18:24:42+02:00 Quantifying Lithogenic Inputs to the Southern Ocean Using Long-Lived Thorium Isotopes Habacuc Pérez-Tribouillier Taryn L. Noble Ashley T. Townsend Andrew R. Bowie Zanna Chase 2020-04-01T00:00:00Z https://doi.org/10.3389/fmars.2020.00207 https://doaj.org/article/5e5a260d24804f9b9066d1e1c14d10f2 EN eng Frontiers Media S.A. https://www.frontiersin.org/article/10.3389/fmars.2020.00207/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2020.00207 https://doaj.org/article/5e5a260d24804f9b9066d1e1c14d10f2 Frontiers in Marine Science, Vol 7 (2020) thorium Southern Ocean Kerguelen Plateau lithogenic natural fertilization GEOTRACES Science Q General. Including nature conservation geographical distribution QH1-199.5 article 2020 ftdoajarticles https://doi.org/10.3389/fmars.2020.00207 2022-12-31T14:55:01Z Thorium (Th) isotopes were applied to quantify the supply of lithogenic inputs from the Kerguelen Plateau to the Southern Ocean. The dissolved concentrations of 232Th and 230Th were measured following a novel pre-concentration method using the Nobias resin from 10 stations above and on the slopes of the plateau. Elevated 232Th/230Th ratios in the upper 500 m of the water column confirm the input of lithogenic material from islands, glaciers and the resuspension of shelf-deposited sediments. 230Th concentrations were used to calculate a scavenging residence time for Th, which was then applied to calculate the flux of dissolved 232Th required to match the observed concentrations of dissolved 232Th. The 232Th content of the lithogenic material from the Kerguelen Plateau was used with the solubility of Th reported in the literature, to estimate a lithogenic particle flux of 7 to 810 mg m–2 day–1. This flux is comparable to fluxes obtained using sediment traps (8–777 mg m–2 day–1) in other continental-margin zones of the Southern Ocean. The flux of dissolved iron, generated by the dissolution of particles, was also calculated (4,189–6,800 nmol m–2 day–1) based on the iron/thorium ratio in the material from the Kerguelen Plateau. This is higher than previous estimates (1,342 nmol m–2 day–1), suggesting the dissolution of particles as the missing source of iron, thus closing the iron budget of the region. This study confirms the utility of long-lived Th isotopes to quantify lithogenic inputs from continental margin settings. Article in Journal/Newspaper Southern Ocean Directory of Open Access Journals: DOAJ Articles Kerguelen Southern Ocean Frontiers in Marine Science 7 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
thorium Southern Ocean Kerguelen Plateau lithogenic natural fertilization GEOTRACES Science Q General. Including nature conservation geographical distribution QH1-199.5 |
spellingShingle |
thorium Southern Ocean Kerguelen Plateau lithogenic natural fertilization GEOTRACES Science Q General. Including nature conservation geographical distribution QH1-199.5 Habacuc Pérez-Tribouillier Taryn L. Noble Ashley T. Townsend Andrew R. Bowie Zanna Chase Quantifying Lithogenic Inputs to the Southern Ocean Using Long-Lived Thorium Isotopes |
topic_facet |
thorium Southern Ocean Kerguelen Plateau lithogenic natural fertilization GEOTRACES Science Q General. Including nature conservation geographical distribution QH1-199.5 |
description |
Thorium (Th) isotopes were applied to quantify the supply of lithogenic inputs from the Kerguelen Plateau to the Southern Ocean. The dissolved concentrations of 232Th and 230Th were measured following a novel pre-concentration method using the Nobias resin from 10 stations above and on the slopes of the plateau. Elevated 232Th/230Th ratios in the upper 500 m of the water column confirm the input of lithogenic material from islands, glaciers and the resuspension of shelf-deposited sediments. 230Th concentrations were used to calculate a scavenging residence time for Th, which was then applied to calculate the flux of dissolved 232Th required to match the observed concentrations of dissolved 232Th. The 232Th content of the lithogenic material from the Kerguelen Plateau was used with the solubility of Th reported in the literature, to estimate a lithogenic particle flux of 7 to 810 mg m–2 day–1. This flux is comparable to fluxes obtained using sediment traps (8–777 mg m–2 day–1) in other continental-margin zones of the Southern Ocean. The flux of dissolved iron, generated by the dissolution of particles, was also calculated (4,189–6,800 nmol m–2 day–1) based on the iron/thorium ratio in the material from the Kerguelen Plateau. This is higher than previous estimates (1,342 nmol m–2 day–1), suggesting the dissolution of particles as the missing source of iron, thus closing the iron budget of the region. This study confirms the utility of long-lived Th isotopes to quantify lithogenic inputs from continental margin settings. |
format |
Article in Journal/Newspaper |
author |
Habacuc Pérez-Tribouillier Taryn L. Noble Ashley T. Townsend Andrew R. Bowie Zanna Chase |
author_facet |
Habacuc Pérez-Tribouillier Taryn L. Noble Ashley T. Townsend Andrew R. Bowie Zanna Chase |
author_sort |
Habacuc Pérez-Tribouillier |
title |
Quantifying Lithogenic Inputs to the Southern Ocean Using Long-Lived Thorium Isotopes |
title_short |
Quantifying Lithogenic Inputs to the Southern Ocean Using Long-Lived Thorium Isotopes |
title_full |
Quantifying Lithogenic Inputs to the Southern Ocean Using Long-Lived Thorium Isotopes |
title_fullStr |
Quantifying Lithogenic Inputs to the Southern Ocean Using Long-Lived Thorium Isotopes |
title_full_unstemmed |
Quantifying Lithogenic Inputs to the Southern Ocean Using Long-Lived Thorium Isotopes |
title_sort |
quantifying lithogenic inputs to the southern ocean using long-lived thorium isotopes |
publisher |
Frontiers Media S.A. |
publishDate |
2020 |
url |
https://doi.org/10.3389/fmars.2020.00207 https://doaj.org/article/5e5a260d24804f9b9066d1e1c14d10f2 |
geographic |
Kerguelen Southern Ocean |
geographic_facet |
Kerguelen Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Frontiers in Marine Science, Vol 7 (2020) |
op_relation |
https://www.frontiersin.org/article/10.3389/fmars.2020.00207/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2020.00207 https://doaj.org/article/5e5a260d24804f9b9066d1e1c14d10f2 |
op_doi |
https://doi.org/10.3389/fmars.2020.00207 |
container_title |
Frontiers in Marine Science |
container_volume |
7 |
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1766205519291219968 |