No change in Southern Ocean circulation in the Indian Ocean from the Eocene through Late Oligocene
Deciphering the evolution of Southern Ocean circulation during the Eocene and Oligocene has important implications for understanding the development of the Antarctic Circumpolar Current and transition to Earth's "icehouse" climate. To better understand ocean circulation patterns in th...
Published in: | Paleoceanography and Paleoclimatology |
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Language: | English |
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2018
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ftsouthampton:oai:eprints.soton.ac.uk:418084 2023-07-30T03:58:39+02:00 No change in Southern Ocean circulation in the Indian Ocean from the Eocene through Late Oligocene Wright, Nicky M. Scher, Howie D. Seton, Maria Huck, Claire E. Duggan, Brian D. 2018-02-05 text https://eprints.soton.ac.uk/418084/ https://eprints.soton.ac.uk/418084/1/816886_1_merged_1512970629.pdf https://eprints.soton.ac.uk/418084/2/2017PA003238.pdf https://eprints.soton.ac.uk/418084/3/816886_1_merged_1512970629.pdf en English eng https://eprints.soton.ac.uk/418084/1/816886_1_merged_1512970629.pdf https://eprints.soton.ac.uk/418084/2/2017PA003238.pdf https://eprints.soton.ac.uk/418084/3/816886_1_merged_1512970629.pdf Wright, Nicky M., Scher, Howie D., Seton, Maria, Huck, Claire E. and Duggan, Brian D. (2018) No change in Southern Ocean circulation in the Indian Ocean from the Eocene through Late Oligocene. Paleoceanography and Paleoclimatology. (doi:10.1002/2017PA003238 <http://dx.doi.org/10.1002/2017PA003238>). Article PeerReviewed 2018 ftsouthampton https://doi.org/10.1002/2017PA003238 2023-07-09T22:20:42Z Deciphering the evolution of Southern Ocean circulation during the Eocene and Oligocene has important implications for understanding the development of the Antarctic Circumpolar Current and transition to Earth's "icehouse" climate. To better understand ocean circulation patterns in the Indian Ocean sector of the Southern Ocean, we generated a new fossil fish tooth neodymium isotope record (ε Nd ) from the upper Eocene to upper Oligocene sections (36-23 Ma) of Ocean Drilling Program Sites 744 and 748 (Kerguelen Plateau, Indian Ocean). Reconstructed seawater ε Nd values from fossil fish teeth are used to trace changes in water masses across ocean basins. The records from Site 748 and Site 744 reveal a gradual shift from ε Nd values around -6.5 to -7.5 in the late Eocene to ε Nd values between -7.5 and -8.3 by the late Oligocene, consistent with a Circumpolar Deep Water (CDW) influence at the Kerguelen Plateau throughout the Oligocene. We interpret the shift to less radiogenic values to reflect the increased export of Northern Component Water to the Southern Ocean, likely into the proto-CDW. However, the records show no major change in water mass composition around the Kerguelen Plateau that would accompany an increase in Pacific throughflow related to the opening of Drake Passage and imply that Pacific throughflow via the Drake Passage occurred by the late Eocene. High-frequency variability in e Nd values at Site 744 is interpreted as an imprint of Oligocene glacial activity, with a particularly pronounced excursion at 32.6 Ma roughly coinciding with other glacial weathering indicators around Antarctica. Article in Journal/Newspaper Antarc* Antarctic Antarctica Drake Passage Southern Ocean University of Southampton: e-Prints Soton Antarctic Drake Passage Indian Kerguelen Pacific Southern Ocean The Antarctic Paleoceanography and Paleoclimatology 33 2 152 167 |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
description |
Deciphering the evolution of Southern Ocean circulation during the Eocene and Oligocene has important implications for understanding the development of the Antarctic Circumpolar Current and transition to Earth's "icehouse" climate. To better understand ocean circulation patterns in the Indian Ocean sector of the Southern Ocean, we generated a new fossil fish tooth neodymium isotope record (ε Nd ) from the upper Eocene to upper Oligocene sections (36-23 Ma) of Ocean Drilling Program Sites 744 and 748 (Kerguelen Plateau, Indian Ocean). Reconstructed seawater ε Nd values from fossil fish teeth are used to trace changes in water masses across ocean basins. The records from Site 748 and Site 744 reveal a gradual shift from ε Nd values around -6.5 to -7.5 in the late Eocene to ε Nd values between -7.5 and -8.3 by the late Oligocene, consistent with a Circumpolar Deep Water (CDW) influence at the Kerguelen Plateau throughout the Oligocene. We interpret the shift to less radiogenic values to reflect the increased export of Northern Component Water to the Southern Ocean, likely into the proto-CDW. However, the records show no major change in water mass composition around the Kerguelen Plateau that would accompany an increase in Pacific throughflow related to the opening of Drake Passage and imply that Pacific throughflow via the Drake Passage occurred by the late Eocene. High-frequency variability in e Nd values at Site 744 is interpreted as an imprint of Oligocene glacial activity, with a particularly pronounced excursion at 32.6 Ma roughly coinciding with other glacial weathering indicators around Antarctica. |
format |
Article in Journal/Newspaper |
author |
Wright, Nicky M. Scher, Howie D. Seton, Maria Huck, Claire E. Duggan, Brian D. |
spellingShingle |
Wright, Nicky M. Scher, Howie D. Seton, Maria Huck, Claire E. Duggan, Brian D. No change in Southern Ocean circulation in the Indian Ocean from the Eocene through Late Oligocene |
author_facet |
Wright, Nicky M. Scher, Howie D. Seton, Maria Huck, Claire E. Duggan, Brian D. |
author_sort |
Wright, Nicky M. |
title |
No change in Southern Ocean circulation in the Indian Ocean from the Eocene through Late Oligocene |
title_short |
No change in Southern Ocean circulation in the Indian Ocean from the Eocene through Late Oligocene |
title_full |
No change in Southern Ocean circulation in the Indian Ocean from the Eocene through Late Oligocene |
title_fullStr |
No change in Southern Ocean circulation in the Indian Ocean from the Eocene through Late Oligocene |
title_full_unstemmed |
No change in Southern Ocean circulation in the Indian Ocean from the Eocene through Late Oligocene |
title_sort |
no change in southern ocean circulation in the indian ocean from the eocene through late oligocene |
publishDate |
2018 |
url |
https://eprints.soton.ac.uk/418084/ https://eprints.soton.ac.uk/418084/1/816886_1_merged_1512970629.pdf https://eprints.soton.ac.uk/418084/2/2017PA003238.pdf https://eprints.soton.ac.uk/418084/3/816886_1_merged_1512970629.pdf |
geographic |
Antarctic Drake Passage Indian Kerguelen Pacific Southern Ocean The Antarctic |
geographic_facet |
Antarctic Drake Passage Indian Kerguelen Pacific Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctica Drake Passage Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Drake Passage Southern Ocean |
op_relation |
https://eprints.soton.ac.uk/418084/1/816886_1_merged_1512970629.pdf https://eprints.soton.ac.uk/418084/2/2017PA003238.pdf https://eprints.soton.ac.uk/418084/3/816886_1_merged_1512970629.pdf Wright, Nicky M., Scher, Howie D., Seton, Maria, Huck, Claire E. and Duggan, Brian D. (2018) No change in Southern Ocean circulation in the Indian Ocean from the Eocene through Late Oligocene. Paleoceanography and Paleoclimatology. (doi:10.1002/2017PA003238 <http://dx.doi.org/10.1002/2017PA003238>). |
op_doi |
https://doi.org/10.1002/2017PA003238 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
33 |
container_issue |
2 |
container_start_page |
152 |
op_container_end_page |
167 |
_version_ |
1772821399542431744 |