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| Malaize, B.; Joly, C.; Venec-peyre, M. -t.; Bassinot, F.; Caillon, N.; Charlier, K.. |
| High-resolution faunal and isotopic analyses of foraminifera were performed on core MD96-2073 (10 degrees 94'N, 52 degrees 62'E, 3142 m depth), located close to Socotra Island in the upwelling area of the Somali Basin ( NW Indian Ocean). This work focuses on Marine Isotopic Stage 6.5 in order to reconstruct paleo-upwelling changes and their links with the Arabian Sea summer monsoon and the migration of the Intertropical Convergence Zone (ITCZ). Correspondence and cluster analyses of planktonic foraminiferal abundances, partly controlled by temperature and water mass productivity, together with an upwelling intensification index, show the occurrence of a strong upwelling between 176 and 165 ka. This upwelling intensification responds to a northward... |
| Tipo: Text |
Palavras-chave: Paleoclimatology; Foraminifera; Isotopes; Indian monsoon; ITCZ; Sapropels; Upwelling. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00234/34487/33433.pdf |
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| Govin, A.; Capron, E.; Tzedakis, P. C.; Verheyden, S.; Ghaleb, B.; Hillaire-marcel, C.; St-onge, G.; Stoner, J. S.; Bassinot, F.; Bazin, L.; Blunier, T.; Combourieu-nebout, N.; El Ouahabi, A.; Genty, D.; Gersonde, R.; Jimenez-amat, P.; Landais, A.; Martrat, B.; Masson-delmotte, V.; Parrenin, F.; Seidenkrantz, M. -s.; Veres, D.; Waelbroeck, C.; Zahn, R.. |
| The Last Interglacial (LIG) represents an invaluable case study to investigate the response of components of the Earth system to global warming. However, the scarcity of absolute age constraints in most archives leads to extensive use of various stratigraphic alignments to different reference chronologies. This feature sets limitations to the accuracy of the stratigraphic assignment of the climatic sequence of events across the globe during the LIG. Here, we review the strengths and limitations of the methods that are commonly used to date or develop chronologies in various climatic archives for the time span (similar to 140 -100 ka) encompassing the penultimate deglaciation, the LIG and the glacial inception. Climatic hypotheses underlying record... |
| Tipo: Text |
Palavras-chave: Last Interglacial; Penultimate deglaciation; Last glacial inception; Chronology; Corals; Speleothems; Ice cores; Marine sediments; Peat and lake sediments; Climate dynamics. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00496/60802/64786.pdf |
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| Schmitt, A.; Elliot, M.; Thirumalai, K.; La, C.; Bassinot, F.; Petersen, J.; Movellan, A.; Jorry, Stephan; Borgomano, J.. |
| The ratio of magnesium to calcium (Mg/Ca) in foraminiferal shells is commonly used as a proxy for past ocean temperature. Recent advances in elemental analyses now enable single-specimen measurements of planktic foraminifera and thus, can provide information on past seasonal and interannual variability, owing to the near-monthly lifespan of foraminifera. In this study, we explore the temperature variance recorded by Mg/Ca in tests of foraminifera Globigerinoides ruber, a planktic species that occurs throughout the year in tropical waters. Using LA-ICP-MS, we characterize Mg/Ca variability in single specimens of two morphotypes of G. ruber picked from a sediment core retrieved offshore New Caledonia. We provide an estimate of the range of calcification... |
| Tipo: Text |
Palavras-chave: Globigerinoides ruber; Mg/Ca ratio; Sea surface temperature; LA-ICPMS; Seasonality; Quaternary. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00472/58336/60890.pdf |
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