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Cartapanis, Olivier; Tachikawa, Kazuyo; Bard, Edouard. |
During the last glacial period, the Oxygen Minimum Zone (OMZ) within the northeastern Pacific Ocean strengthened and weakened on a millennial time scale, demonstrating a tight linkage with northern high latitude climate, although the precise mechanisms responsible remain unknown. Core MD02-2508, retrieved off Baja California, was analyzed for major and trace elements (Br, Ca, Ti, Fe, Mn, and Sr) using a XRF scanner and redox-sensitive trace elements (Cu, Ni, Cd, As, V, Cr, Mo, and U) using the ICP-MS. The trace element content, the Fe/Ti ratio, and Br-based organic carbon exhibit higher values during the Holocene and during warm Dansgaard-Oeschger events than during the Last Glacial Maximum (LGM), stadials, and Heinrich (H) events. A principal component... |
Tipo: Text |
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Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00227/33799/32550.pdf |
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Lippold, Jorg; Gutjahr, Marcus; Blaser, Patrick; Christner, Emanuel; Ferreria, Maria Luiza De Carvalho; Mulitza, Stefan; Christl, Marcus; Wombacher, Frank; Böhm, Evelyn; Antz, Benny; Cartapanis, Olivier; Vogel, Hendrik; Jaccard, Samuel L.. |
Reconstructing past modes of ocean circulation is an essential task in paleoclimatology and paleoceanography. To this end, we combine two sedimentary proxies, Nd isotopes (epsilon(Nd)) and the Pa-231/Th-230 ratio, both of which are not directly involved in the global carbon cycle, but allow the reconstruction of water mass provenance and provide information about the past strength of overturning circulation, respectively. In this study, combined Pa-231/Th-230 and epsilon(Nd) down-core profiles from six Atlantic Ocean sediment cores are presented. The data set is complemented by the two available combined data sets from the literature. From this we derive a comprehensive picture of spatial and temporal patterns and the dynamic changes of the Atlantic... |
Tipo: Text |
Palavras-chave: Pa-231/Th-230; Epsilon(Nd); Atlantic Meridional Overturning Circulation; Deep sea sediments; Last Glacial Maximum; Deglaciation. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53236/54762.pdf |
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Schmittner, Andreas; Bostock, Helen C.; Cartapanis, Olivier; Curry, William B.; Filipsson, Helena L.; Galbraith, Eric D.; Gottschalk, Julia; Carlos Herguera, Juan; Hoogakker, Babette; Jaccard, Samuel L.; Lisiecki, Lorraine E.; Lund, David C.; Martinez-mendez, Gema; Lynch-stieglitz, Jean; Mackensen, Andreas; Michel, Elisabeth; Mix, Alan C.; Oppo, Delia W.; Peterson, Carlye D.; Repschlaeger, Janne; Sikes, Elisabeth L.; Spero, Howard J.; Waelbroeck, Claire. |
The carbon isotope composition (C-13) of seawater provides valuable insight on ocean circulation, air-sea exchange, the biological pump, and the global carbon cycle and is reflected by the C-13 of foraminifera tests. Here more than 1700 C-13 observations of the benthic foraminifera genus Cibicides from late Holocene sediments (C-13(Cibnat)) are compiled and compared with newly updated estimates of the natural (preindustrial) water column C-13 of dissolved inorganic carbon (C-13(DICnat)) as part of the international Ocean Circulation and Carbon Cycling (OC3) project. Using selection criteria based on the spatial distance between samples, we find high correlation between C-13(Cibnat) and C-13(DICnat), confirming earlier work. Regression analyses indicate... |
Tipo: Text |
Palavras-chave: Carbon; Isotopes; Benthic; Foraminifera; Calibration. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00661/77326/78788.pdf |
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