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Provedor de dados:  ArchiMer
País:  France
Título:  Constraints on surface seawater oxygen isotope change between the Last Glacial Maximum and the Late Holocene
Autores:  Waelbroeck, C.
Kiefer, T.
Dokken, T.
Chen, M. -t.
Spero, H. J.
Jung, S.
Weinelt, M.
Kucera, M.
Paul, A.
Data:  2014-12-01
Ano:  2014
Palavras-chave:  Paleoceanography
Surface water oxygen isotopic ratio
Planktonic foraminifers
Last Glacial Maximum
Resumo:  Estimates of the change in surface seawater delta O-18 (delta O-18(sw)) between the Last Glacial Maximum (LGM) and Late Holocene (LH) are derived from homogenous data sets with rigorous age control, namely MARGO sea surface temperature (SST) estimates and oxygen isotopic ratios (delta O-18) of planktonic foraminifers. Propagation of uncertainties associated with each proxy allows the identification of robust patterns of change in delta O-18(sw). Examination of these patterns on a regional scale highlights which changes in surface currents and hydrological cycle are consistent with both planktonic isotopic data and reconstructed SST. Positive local annual mean LGM-LH delta O-18(sw) anomalies characterize the glacial tropical Indian Ocean, portions of the western and eastern margins of the North Pacific, the Iberian margin and the tropical North Atlantic, as well as the South African margin. Although reduced precipitation during the LGM with respect to the LH may have contributed to some extent to these local enrichments in surface seawater O-18, the largest positive anomalies appear to be related to changes in ocean circulation. Large local negative annual mean LGM-LH delta O-18(sw) are found in the South Pacific and North Atlantic, reflecting the equatorward migration of surface temperature fronts during the LGM with respect to the LH. In the northern North Atlantic, a region characterized by large discrepancies between SST estimates based on different proxies, only SST estimates based on planktonic foraminifer counts yield annual mean LGM-LH delta O-18(sw) anomalies consistent with a southward shift of the polar front at the LGM relative to the LH.
Tipo:  Text
Idioma:  Inglês

Editor:  Pergamon-elsevier Science Ltd
Formato:  application/pdf
Fonte:  Quaternary Science Reviews (0277-3791) (Pergamon-elsevier Science Ltd), 2014-12-01 , Vol. 105 , P. 102-111
Direitos:  2014 Elsevier Ltd. All rights reserved.


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