Deep ocean carbonate ion increase during mid Miocene CO2 decline
Characterised by long term cooling and abrupt ice sheet expansion on Antarctica ~14 Ma ago, the mid Miocene marked the beginning of the modern ice-house world, yet there is still little consensus on its causes, in part because carbon cycle dynamics are not well constrained. In particular, changes in...
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ftanucanberra:oai:digitalcollections.anu.edu.au:1885/57446 2023-05-15T13:56:44+02:00 Deep ocean carbonate ion increase during mid Miocene CO2 decline Kender, S. Yu, Jimin Peck, V.L. 2015-12-10T22:40:23Z http://hdl.handle.net/1885/57446 unknown Nature Publishing Group 2045-2322 http://hdl.handle.net/1885/57446 Scientific Reports Journal article 2015 ftanucanberra 2015-12-21T23:36:22Z Characterised by long term cooling and abrupt ice sheet expansion on Antarctica ~14 Ma ago, the mid Miocene marked the beginning of the modern ice-house world, yet there is still little consensus on its causes, in part because carbon cycle dynamics are not well constrained. In particular, changes in carbonate ion concentration ([CO3(2-)]) in the ocean, the largest carbon reservoir of the ocean-land-atmosphere system, are poorly resolved. We use benthic foraminiferal B/Ca ratios to reconstruct relative changes in [CO3(2-)] from the South Atlantic, East Pacific, and Southern Oceans. Our results suggest an increase of perhaps ~40 μmol/kg may have occurred between ~15 and 14 Ma in intermediate to deep waters in each basin. This long-term increase suggests elevated alkalinity input, perhaps from the Himalaya, rather than other shorter-term mechanisms such as ocean circulation or ecological changes, and may account for some of the proposed atmospheric CO2 decline before ~14 Ma. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Australian National University: ANU Digital Collections Pacific |
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Open Polar |
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Australian National University: ANU Digital Collections |
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ftanucanberra |
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unknown |
description |
Characterised by long term cooling and abrupt ice sheet expansion on Antarctica ~14 Ma ago, the mid Miocene marked the beginning of the modern ice-house world, yet there is still little consensus on its causes, in part because carbon cycle dynamics are not well constrained. In particular, changes in carbonate ion concentration ([CO3(2-)]) in the ocean, the largest carbon reservoir of the ocean-land-atmosphere system, are poorly resolved. We use benthic foraminiferal B/Ca ratios to reconstruct relative changes in [CO3(2-)] from the South Atlantic, East Pacific, and Southern Oceans. Our results suggest an increase of perhaps ~40 μmol/kg may have occurred between ~15 and 14 Ma in intermediate to deep waters in each basin. This long-term increase suggests elevated alkalinity input, perhaps from the Himalaya, rather than other shorter-term mechanisms such as ocean circulation or ecological changes, and may account for some of the proposed atmospheric CO2 decline before ~14 Ma. |
format |
Article in Journal/Newspaper |
author |
Kender, S. Yu, Jimin Peck, V.L. |
spellingShingle |
Kender, S. Yu, Jimin Peck, V.L. Deep ocean carbonate ion increase during mid Miocene CO2 decline |
author_facet |
Kender, S. Yu, Jimin Peck, V.L. |
author_sort |
Kender, S. |
title |
Deep ocean carbonate ion increase during mid Miocene CO2 decline |
title_short |
Deep ocean carbonate ion increase during mid Miocene CO2 decline |
title_full |
Deep ocean carbonate ion increase during mid Miocene CO2 decline |
title_fullStr |
Deep ocean carbonate ion increase during mid Miocene CO2 decline |
title_full_unstemmed |
Deep ocean carbonate ion increase during mid Miocene CO2 decline |
title_sort |
deep ocean carbonate ion increase during mid miocene co2 decline |
publisher |
Nature Publishing Group |
publishDate |
2015 |
url |
http://hdl.handle.net/1885/57446 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Antarc* Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctica Ice Sheet |
op_source |
Scientific Reports |
op_relation |
2045-2322 http://hdl.handle.net/1885/57446 |
_version_ |
1766264311493165056 |