Coccolithophore variability across Marine Isotope Stage 11 in the Pacific sector of the Southern Ocean and its potential impact on the carbon cycle
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- Mariem Saavedra‐Pellitero
- Department of Geosciences University of Bremen Bremen Germany
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- Karl‐Heinz Baumann
- Department of Geosciences University of Bremen Bremen Germany
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- Frank Lamy
- Alfred‐Wegener‐Institut Helmholtz‐Zentrum für Polar‐und Meeresforschung Bremerhaven Germany
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- Peter Köhler
- Alfred‐Wegener‐Institut Helmholtz‐Zentrum für Polar‐und Meeresforschung Bremerhaven Germany
抄録
<jats:title>Abstract</jats:title><jats:p>Proxy‐based reconstructions of past changes in the marine biological carbon pumps are limited, especially in the Southern Ocean. This work provides new insights into the productivity variations in the Pacific sector of the Southern Ocean. We present new data derived from three sediment cores that show glacial/interglacial coccolithophore variability across Marine Isotope Stage 11 (MIS 11). The cores were retrieved during R/V <jats:italic>Polarstern</jats:italic> cruise PS75 from the Subantarctic Zone and Polar Front Zone at the western flank of the East Pacific Rise and in the vicinity of the Antarctic‐Pacific Ridge. Coccolithophore assemblages were overwhelmingly dominated by the species <jats:italic>Gephyrocapsa caribbeanica</jats:italic> and small <jats:italic>Gephyrocapsa</jats:italic>. Total numbers of coccoliths, coccolith accumulation rates, coccolith fraction (CF; <20 μm fraction) Sr/Ca data, and temperature‐corrected CF Sr/Ca records consistently showed an increase in coccolithophore productivity during Termination V (MIS 12‐11 boundary), highest productivity throughout MIS 11 (~424–374 kyr), and a decrease during late MIS 11 in all the cores. We end with a discussion of back‐calculated coccolith calcification rate in the surface ocean and its potential contribution to changes in the concentration of atmospheric CO<jats:sub>2</jats:sub>.</jats:p>
収録刊行物
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- Paleoceanography
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Paleoceanography 32 (8), 864-880, 2017-08
American Geophysical Union (AGU)