Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/175983
Title: The Evolution of Deep Ocean Chemistry and Respired Carbon in the Eastern Equatorial Pacific Over the Last Deglaciation
Author: De la Fuente, M.
Calvo, Eva
Skinner, L.
Pelejero Bou, Carles
Evans, David
Mueller, Wolfgang
Povea de Castro, Patricia
Cacho Lascorz, Isabel
Keywords: Paleoceanografia
Pacífic, Oceà
Sediments marins
Circulació oceànica
Períodes glacials
Paleoceanography
Pacific Ocean
Marine sediments
Ocean circulation
Glacial epoch
Issue Date: 1-Dec-2017
Publisher: American Geophysical Union (AGU)
Abstract: It has been shown that the deep Eastern Equatorial Pacific (EEP) region was poorly ventilated during the Last Glacial Maximum (LGM) relative to Holocene values. This finding suggests a more efficient biological pump, which indirectly supports the idea of increased carbon storage in the deep ocean contributing to lower atmospheric CO2 during the last glacial. However, proxies related to respired carbon are needed in order to directly test this proposition. Here we present Cibicides wuellerstorfi B/Ca ratios from Ocean Drilling Program Site 1240 measured by laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) as a proxy for deep water carbonate saturation state ([CO32-], and therefore [CO32-]), along with C-13 measurements. In addition, the U/Ca ratio in foraminiferal coatings has been analyzed as an indicator of oxygenation changes. Our results show lower [CO32-], C-13, and [O-2] values during the LGM, which would be consistent with higher respired carbon levels in the deep EEP driven, at least in part, by reduced deep water ventilation. However, the difference between LGM and Holocene [CO32-] observed at our site is relatively small, in accordance with other records from across the Pacific, suggesting that a counteracting mechanism, such as seafloor carbonate dissolution, also played a role. If so, this mechanism would have increased average ocean alkalinity, allowing even more atmospheric CO2 to be sequestered by the ocean. Therefore, the deep Pacific Ocean very likely stored a significant amount of atmospheric CO2 during the LGM, specifically due to a more efficient biological carbon pump and also an increase in average ocean alkalinity.
Note: Reproducció del document publicat a: https://doi.org/10.1002/2017PA003155
It is part of: Paleoceanography, 2017, vol. 32, num. 12, p. 1371-1385
URI: http://hdl.handle.net/2445/175983
Related resource: https://doi.org/10.1002/2017PA003155
ISSN: 0883-8305
Appears in Collections:Articles publicats en revistes (Dinàmica de la Terra i l'Oceà)

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