Silicon isotope and silicic acid uptake in surface waters of Marguerite Bay, West Antarctic Peninsula
The silicon isotope composition (δ30Si) of dissolved silicon (DSi) and biogenic silica (BSi) provides information about the silicon cycle and its role in oceanic carbon uptake in the modern ocean and in the past. However, there are still questions outstanding regarding the impact of processes such a...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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Online Access: | http://nora.nerc.ac.uk/id/eprint/512258/ https://nora.nerc.ac.uk/id/eprint/512258/1/Silicon%20isotope%20and%20silicic%20acid%20uptake%20in%20surface%20waters%20of%20Marguerite%20Bay%20AAM.pdf http://www.sciencedirect.com/science/article/pii/S0967064516303216 |
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ftnerc:oai:nora.nerc.ac.uk:512258 2023-05-15T13:49:32+02:00 Silicon isotope and silicic acid uptake in surface waters of Marguerite Bay, West Antarctic Peninsula Cassarino, Lucie Hendry, Katharine R. Meredith, Michael P. Venables, Hugh J. De La Rocha, Christina L. 2017-05 text http://nora.nerc.ac.uk/id/eprint/512258/ https://nora.nerc.ac.uk/id/eprint/512258/1/Silicon%20isotope%20and%20silicic%20acid%20uptake%20in%20surface%20waters%20of%20Marguerite%20Bay%20AAM.pdf http://www.sciencedirect.com/science/article/pii/S0967064516303216 en eng Elsevier https://nora.nerc.ac.uk/id/eprint/512258/1/Silicon%20isotope%20and%20silicic%20acid%20uptake%20in%20surface%20waters%20of%20Marguerite%20Bay%20AAM.pdf Cassarino, Lucie; Hendry, Katharine R.; Meredith, Michael P. orcid:0000-0002-7342-7756 Venables, Hugh J.; De La Rocha, Christina L. 2017 Silicon isotope and silicic acid uptake in surface waters of Marguerite Bay, West Antarctic Peninsula. Deep Sea Research II: Topical Studies in Oceanography, 139. 143-150. https://doi.org/10.1016/j.dsr2.2016.11.002 <https://doi.org/10.1016/j.dsr2.2016.11.002> Marine Sciences Chemistry Publication - Article PeerReviewed 2017 ftnerc https://doi.org/10.1016/j.dsr2.2016.11.002 2023-02-04T19:42:24Z The silicon isotope composition (δ30Si) of dissolved silicon (DSi) and biogenic silica (BSi) provides information about the silicon cycle and its role in oceanic carbon uptake in the modern ocean and in the past. However, there are still questions outstanding regarding the impact of processes such as oceanic mixing, export and dissolution on the isotopic signature of seawater, and the impacts on sedimentary BSi. This study reports the δ30Si of DSi from surface waters at the Rothera Time Series (RaTS) site, Ryder Bay, in a coastal region of the West Antarctic Peninsula (WAP). The samples were collected at the end of austral spring through the end of austral summer/beginning of autumn over two field seasons, 2004/5 and 2005/6. Broadly, for both field seasons, DSi diminished and δ30Si of DSi increased through the summer, but this was accomplished during only a few short periods of net nutrient drawdown. During these periods, the δ30Si of DSi was negatively correlated with DSi concentrations. The Si isotope fractionation factor determined for the net nutrient drawdown periods, ɛuptake, was in the range of -2.26 to -1.80‰ when calculated using an open system model and -1.93 to -1.33‰ when using a closed system model. These estimates of ɛ are somewhat higher than previous studies that relied on snapshots in time rather than following changes in δ30Si and DSi over time, which therefore were more likely to include the effects of mixing of dissolved silicon up into the mixed layer. Results highlight also that, even at the same station and within a single growing season, the apparent fractionation factor may exhibit significant temporal variability because of changes in the extent of biological removal of DSi, nutrient source, siliceous species, and mixing events. Paleoceanographic studies using silicon isotopes need careful consideration in the light of our new results. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Natural Environment Research Council: NERC Open Research Archive Antarctic Antarctic Peninsula Austral Marguerite ENVELOPE(141.378,141.378,-66.787,-66.787) Rothera ENVELOPE(-68.130,-68.130,-67.568,-67.568) Marguerite Bay ENVELOPE(-68.000,-68.000,-68.500,-68.500) Ryder ENVELOPE(-68.333,-68.333,-67.566,-67.566) Ryder Bay ENVELOPE(-68.333,-68.333,-67.567,-67.567) Deep Sea Research Part II: Topical Studies in Oceanography 139 143 150 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
topic |
Marine Sciences Chemistry |
spellingShingle |
Marine Sciences Chemistry Cassarino, Lucie Hendry, Katharine R. Meredith, Michael P. Venables, Hugh J. De La Rocha, Christina L. Silicon isotope and silicic acid uptake in surface waters of Marguerite Bay, West Antarctic Peninsula |
topic_facet |
Marine Sciences Chemistry |
description |
The silicon isotope composition (δ30Si) of dissolved silicon (DSi) and biogenic silica (BSi) provides information about the silicon cycle and its role in oceanic carbon uptake in the modern ocean and in the past. However, there are still questions outstanding regarding the impact of processes such as oceanic mixing, export and dissolution on the isotopic signature of seawater, and the impacts on sedimentary BSi. This study reports the δ30Si of DSi from surface waters at the Rothera Time Series (RaTS) site, Ryder Bay, in a coastal region of the West Antarctic Peninsula (WAP). The samples were collected at the end of austral spring through the end of austral summer/beginning of autumn over two field seasons, 2004/5 and 2005/6. Broadly, for both field seasons, DSi diminished and δ30Si of DSi increased through the summer, but this was accomplished during only a few short periods of net nutrient drawdown. During these periods, the δ30Si of DSi was negatively correlated with DSi concentrations. The Si isotope fractionation factor determined for the net nutrient drawdown periods, ɛuptake, was in the range of -2.26 to -1.80‰ when calculated using an open system model and -1.93 to -1.33‰ when using a closed system model. These estimates of ɛ are somewhat higher than previous studies that relied on snapshots in time rather than following changes in δ30Si and DSi over time, which therefore were more likely to include the effects of mixing of dissolved silicon up into the mixed layer. Results highlight also that, even at the same station and within a single growing season, the apparent fractionation factor may exhibit significant temporal variability because of changes in the extent of biological removal of DSi, nutrient source, siliceous species, and mixing events. Paleoceanographic studies using silicon isotopes need careful consideration in the light of our new results. |
format |
Article in Journal/Newspaper |
author |
Cassarino, Lucie Hendry, Katharine R. Meredith, Michael P. Venables, Hugh J. De La Rocha, Christina L. |
author_facet |
Cassarino, Lucie Hendry, Katharine R. Meredith, Michael P. Venables, Hugh J. De La Rocha, Christina L. |
author_sort |
Cassarino, Lucie |
title |
Silicon isotope and silicic acid uptake in surface waters of Marguerite Bay, West Antarctic Peninsula |
title_short |
Silicon isotope and silicic acid uptake in surface waters of Marguerite Bay, West Antarctic Peninsula |
title_full |
Silicon isotope and silicic acid uptake in surface waters of Marguerite Bay, West Antarctic Peninsula |
title_fullStr |
Silicon isotope and silicic acid uptake in surface waters of Marguerite Bay, West Antarctic Peninsula |
title_full_unstemmed |
Silicon isotope and silicic acid uptake in surface waters of Marguerite Bay, West Antarctic Peninsula |
title_sort |
silicon isotope and silicic acid uptake in surface waters of marguerite bay, west antarctic peninsula |
publisher |
Elsevier |
publishDate |
2017 |
url |
http://nora.nerc.ac.uk/id/eprint/512258/ https://nora.nerc.ac.uk/id/eprint/512258/1/Silicon%20isotope%20and%20silicic%20acid%20uptake%20in%20surface%20waters%20of%20Marguerite%20Bay%20AAM.pdf http://www.sciencedirect.com/science/article/pii/S0967064516303216 |
long_lat |
ENVELOPE(141.378,141.378,-66.787,-66.787) ENVELOPE(-68.130,-68.130,-67.568,-67.568) ENVELOPE(-68.000,-68.000,-68.500,-68.500) ENVELOPE(-68.333,-68.333,-67.566,-67.566) ENVELOPE(-68.333,-68.333,-67.567,-67.567) |
geographic |
Antarctic Antarctic Peninsula Austral Marguerite Rothera Marguerite Bay Ryder Ryder Bay |
geographic_facet |
Antarctic Antarctic Peninsula Austral Marguerite Rothera Marguerite Bay Ryder Ryder Bay |
genre |
Antarc* Antarctic Antarctic Peninsula |
genre_facet |
Antarc* Antarctic Antarctic Peninsula |
op_relation |
https://nora.nerc.ac.uk/id/eprint/512258/1/Silicon%20isotope%20and%20silicic%20acid%20uptake%20in%20surface%20waters%20of%20Marguerite%20Bay%20AAM.pdf Cassarino, Lucie; Hendry, Katharine R.; Meredith, Michael P. orcid:0000-0002-7342-7756 Venables, Hugh J.; De La Rocha, Christina L. 2017 Silicon isotope and silicic acid uptake in surface waters of Marguerite Bay, West Antarctic Peninsula. Deep Sea Research II: Topical Studies in Oceanography, 139. 143-150. https://doi.org/10.1016/j.dsr2.2016.11.002 <https://doi.org/10.1016/j.dsr2.2016.11.002> |
op_doi |
https://doi.org/10.1016/j.dsr2.2016.11.002 |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
139 |
container_start_page |
143 |
op_container_end_page |
150 |
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1766251513768837120 |