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| Tzedakis, P. C.; Drysdale, R. N.; Margari, V.; Skinner, L. C.; Menviel, L.; Rhodes, R. H.; Taschetto, A. S.; Hodell, D. A.; Crowhurst, S. J.; Hellstrom, J. C.; Fallick, A. E.; Grimalt, J. O.; Mcmanus, J. F.; Martrat, B.; Mokeddem, Zohra; Parrenin, F.; Regattieri, E.; Roe, K.; Zanchetta, G.. |
| Considerable ambiguity remains over the extent and nature of millennial/centennial-scale climate instability during the Last Interglacial (LIG). Here we analyse marine and terrestrial proxies from a deep-sea sediment sequence on the Portuguese Margin and combine results with an intensively dated Italian speleothem record and climate-model experiments. The strongest expression of climate variability occurred during the transitions into and out of the LIG. Our records also document a series of multi-centennial intra-interglacial arid events in southern Europe, coherent with cold water-mass expansions in the North Atlantic. The spatial and temporal fingerprints of these changes indicate a reorganization of ocean surface circulation, consistent with... |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57261/59304.pdf |
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| Berger, A.; Crucifix, M.; Hodell, D. A.; Mangili, C.; Mcmanus, J. F.; Otto-bliesner, B.; Pol, K.; Raynaud, D.; Skinner, L. C.; Tzedakis, P. C.; Wolff, E. W.; Yin, Q. Z.; Abe-ouchi, A.; Barbante, C.; Brovkin, V.; Cacho, I.; Capron, E.; Ferretti, P.; Ganopolski, A.; Grimalt, J. O.; Hoenisch, B.; Kawamura, K.; Landais, A.; Margari, V.; Martrat, B.; Masson-delmotte, V.; Mokeddem, Zohra; Parrenin, F.; Prokopenko, A. A.; Rashid, H.; Schulz, M.; Riveiros, N. Vazquez. |
| Interglacials, including the present (Holocene) period, are warm, low land ice extent (high sea level), end-members of glacial cycles. Based on a sea level definition, we identify eleven interglacials in the last 800,000years, a result that is robust to alternative definitions. Data compilations suggest that despite spatial heterogeneity, Marine Isotope Stages (MIS) 5e (last interglacial) and 11c (similar to 400ka ago) were globally strong (warm), while MIS 13a (similar to 500ka ago) was cool at many locations. A step change in strength of interglacials at 450ka is apparent only in atmospheric CO2 and in Antarctic and deep ocean temperature. The onset of an interglacial (glacial termination) seems to require a reducing precession parameter (increasing... |
| Tipo: Text |
Palavras-chave: Interglacials; Review; Quaternary. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00340/45150/44547.pdf |
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| Rama-corredor, O.; Martrat, B.; Grimalt, J. O.; Lopez-otalvaro, G. E.; Flores, J. A.; Sierro, F.. |
| Sea surface temperatures (SST) in the Guiana Basin over the last 140 ka were obtained by measuring the C37 alkenone unsaturation index Uk'37 in the sediment core MD03-2616 (7° N, 53° W). The resulting data set is unique in the western tropical Atlantic region for this period. The SSTs range from 25.1 to 28.9 °C, i.e. glacial–interglacial amplitude of 3.8 °C, which is in the range of change of other tropical areas. During the last two interglacial stages (marine isotope stages; MIS1 and MIS5e) and warm long interstadials (MIS5d-a), a rapid transmission of climate variability from Arctic–tropical latitudes is recorded. During these periods, the MD03-2616 SSTs show a conspicuous parallelism with temperature changes observed in Greenland and SST records of... |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00296/40765/39760.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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