The silicon isotopic composition of surface waters in the Atlantic and Indian sectors of the Southern Ocean
We report here the silicon isotopic composition (delta(30)Si) of dissolved silicon (DSi) from 42 surface water samples from the Drake Passage, the Weddell Gyre, other areas south of the Southern Boundary of the Antarctic Circumpolar Current (ACC), and the ACC near the Kerguelen Plateau, taken betwee...
Published in: | Geochimica et Cosmochimica Acta |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Pergamon-elsevier Science Ltd
2011
|
Subjects: | |
Online Access: | https://archimer.ifremer.fr/doc/00042/15372/12791.pdf https://doi.org/10.1016/j.gca.2011.06.028 https://archimer.ifremer.fr/doc/00042/15372/ |
id |
ftarchimer:oai:archimer.ifremer.fr:15372 |
---|---|
record_format |
openpolar |
spelling |
ftarchimer:oai:archimer.ifremer.fr:15372 2023-05-15T13:47:21+02:00 The silicon isotopic composition of surface waters in the Atlantic and Indian sectors of the Southern Ocean De La Rocha, Christina L. Bescont, Pierre Croguennoc, Alice Ponzevera, Emmanuel 2011-09 application/pdf https://archimer.ifremer.fr/doc/00042/15372/12791.pdf https://doi.org/10.1016/j.gca.2011.06.028 https://archimer.ifremer.fr/doc/00042/15372/ eng eng Pergamon-elsevier Science Ltd https://archimer.ifremer.fr/doc/00042/15372/12791.pdf doi:10.1016/j.gca.2011.06.028 https://archimer.ifremer.fr/doc/00042/15372/ 2011 Elsevier Ltd All rights reserved. info:eu-repo/semantics/openAccess restricted use Geochimica Et Cosmochimica Acta (0016-7037) (Pergamon-elsevier Science Ltd), 2011-09 , Vol. 75 , N. 18 , P. 5283-5295 text Publication info:eu-repo/semantics/article 2011 ftarchimer https://doi.org/10.1016/j.gca.2011.06.028 2021-09-23T20:19:41Z We report here the silicon isotopic composition (delta(30)Si) of dissolved silicon (DSi) from 42 surface water samples from the Drake Passage, the Weddell Gyre, other areas south of the Southern Boundary of the Antarctic Circumpolar Current (ACC), and the ACC near the Kerguelen Plateau, taken between the beginning of February and the end of March 2007. From the beginning to end of the cruise (ANTXXIII/9), DSi diminished in the Antarctic by 50 mu mol L(-1) while concentrations of nitrate + nitrite and phosphate showed no net decline, indicating that the high seasonal Si/N removal ratios well known for the Southern Ocean may be more related to the strength of the silicate pump in the Southern Ocean than to the instantaneous Si/N uptake ratio of diatoms. The delta(30)Si of DSi in samples containing more than 20 mu M DSi were strongly negatively correlated to DSi concentrations, supporting the use of delta(30)Si as a proxy for DSi removal. The "open system" fractionation observed, epsilon = -1.2 +/- 0.11 parts per thousand, agrees well with results from previous work in other areas, and the estimate of the initial delta(30)Si of DSi of + 1.4 parts per thousand is not far off observations of the delta(30)Si of DSi in Winter Water (WW) in this area. Results were used to model DSi draw down in the past from the delta(30)Si of sediment cores, although isotopic fractionation during silica dissolution appeared to influence the d 30 Si of some surface water samples, inviting further study of this phenomenon. (C) 2011 Elsevier Ltd. All rights reserved. Article in Journal/Newspaper Antarc* Antarctic Drake Passage Southern Ocean Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Antarctic Drake Passage Indian Kerguelen Southern Ocean The Antarctic Weddell Geochimica et Cosmochimica Acta 75 18 5283 5295 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
description |
We report here the silicon isotopic composition (delta(30)Si) of dissolved silicon (DSi) from 42 surface water samples from the Drake Passage, the Weddell Gyre, other areas south of the Southern Boundary of the Antarctic Circumpolar Current (ACC), and the ACC near the Kerguelen Plateau, taken between the beginning of February and the end of March 2007. From the beginning to end of the cruise (ANTXXIII/9), DSi diminished in the Antarctic by 50 mu mol L(-1) while concentrations of nitrate + nitrite and phosphate showed no net decline, indicating that the high seasonal Si/N removal ratios well known for the Southern Ocean may be more related to the strength of the silicate pump in the Southern Ocean than to the instantaneous Si/N uptake ratio of diatoms. The delta(30)Si of DSi in samples containing more than 20 mu M DSi were strongly negatively correlated to DSi concentrations, supporting the use of delta(30)Si as a proxy for DSi removal. The "open system" fractionation observed, epsilon = -1.2 +/- 0.11 parts per thousand, agrees well with results from previous work in other areas, and the estimate of the initial delta(30)Si of DSi of + 1.4 parts per thousand is not far off observations of the delta(30)Si of DSi in Winter Water (WW) in this area. Results were used to model DSi draw down in the past from the delta(30)Si of sediment cores, although isotopic fractionation during silica dissolution appeared to influence the d 30 Si of some surface water samples, inviting further study of this phenomenon. (C) 2011 Elsevier Ltd. All rights reserved. |
format |
Article in Journal/Newspaper |
author |
De La Rocha, Christina L. Bescont, Pierre Croguennoc, Alice Ponzevera, Emmanuel |
spellingShingle |
De La Rocha, Christina L. Bescont, Pierre Croguennoc, Alice Ponzevera, Emmanuel The silicon isotopic composition of surface waters in the Atlantic and Indian sectors of the Southern Ocean |
author_facet |
De La Rocha, Christina L. Bescont, Pierre Croguennoc, Alice Ponzevera, Emmanuel |
author_sort |
De La Rocha, Christina L. |
title |
The silicon isotopic composition of surface waters in the Atlantic and Indian sectors of the Southern Ocean |
title_short |
The silicon isotopic composition of surface waters in the Atlantic and Indian sectors of the Southern Ocean |
title_full |
The silicon isotopic composition of surface waters in the Atlantic and Indian sectors of the Southern Ocean |
title_fullStr |
The silicon isotopic composition of surface waters in the Atlantic and Indian sectors of the Southern Ocean |
title_full_unstemmed |
The silicon isotopic composition of surface waters in the Atlantic and Indian sectors of the Southern Ocean |
title_sort |
silicon isotopic composition of surface waters in the atlantic and indian sectors of the southern ocean |
publisher |
Pergamon-elsevier Science Ltd |
publishDate |
2011 |
url |
https://archimer.ifremer.fr/doc/00042/15372/12791.pdf https://doi.org/10.1016/j.gca.2011.06.028 https://archimer.ifremer.fr/doc/00042/15372/ |
geographic |
Antarctic Drake Passage Indian Kerguelen Southern Ocean The Antarctic Weddell |
geographic_facet |
Antarctic Drake Passage Indian Kerguelen Southern Ocean The Antarctic Weddell |
genre |
Antarc* Antarctic Drake Passage Southern Ocean |
genre_facet |
Antarc* Antarctic Drake Passage Southern Ocean |
op_source |
Geochimica Et Cosmochimica Acta (0016-7037) (Pergamon-elsevier Science Ltd), 2011-09 , Vol. 75 , N. 18 , P. 5283-5295 |
op_relation |
https://archimer.ifremer.fr/doc/00042/15372/12791.pdf doi:10.1016/j.gca.2011.06.028 https://archimer.ifremer.fr/doc/00042/15372/ |
op_rights |
2011 Elsevier Ltd All rights reserved. info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1016/j.gca.2011.06.028 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
75 |
container_issue |
18 |
container_start_page |
5283 |
op_container_end_page |
5295 |
_version_ |
1766246959302049792 |