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| Crosta, X.; Debret, M.; Denis, D.; Courty, M. A.; Ther, O.. |
| Diatom data from a marine sediment core give insight on Holocene changes in sea- surface conditions and climate at high southern latitudes off Adelie Land, East Antarctica. The early to mid- Holocene was warmer than the late Holocene with a transition at similar to 4000 calendar years B. P. Sea ice was less present and spring- summer growing season was greater during the warm period relative to the cold one, thus limiting sea ice diatom production and favoring more open ocean diatom to develop. The long- term Holocene climatic evolution in East Antarctica is explained by a combination of a delayed response to local seasonal insolation changes coupled to the long memory of the Southern Ocean. Abrupt variations of the diatom relative abundances, indicating... |
| Tipo: Text |
Palavras-chave: Antarctica; Sea ice; Holocene; Insolation; Thermohaline circulation. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00235/34642/33044.pdf |
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| Siani, G.; Magny, M.; Paterne, M.; Debret, M.; Fontugne, M.. |
| Holocene paleohydrology reconstruction is derived combining planktonic and benthic stable oxygen and carbon isotopes, sea surface temperatures (SSTs) and oxygen isotope composition of seawater (delta O-18(w)) from a high sedimentation core collected in the South Adriatic Sea (SAS). Core chronology is based on 10 AMS C-14 measures on planktonic foraminifera and tephra layers. Results reveal two contrasted paleohydrological periods that reflect (i) a marked lowering of delta O-18(w)/salinity during the early to mid-Holocene (11.5 ka to 6.3 ka), including the two-step sapropel S1 deposition, followed during the mid-to upper Holocene by (ii) a prevailing period of increased salinity and enhanced arid conditions in the South Adriatic Basin. Superimposed on... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00181/29204/27583.pdf |
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| Debret, M.; Bout-roumazeilles, V.; Grousset, F.; Desmet, M.; Mcmanus, J. F.; Massei, N.; Sebag, D.; Petit, J. -r.; Copard, Y.; Trentesaux, A.. |
| Since the first suggestion of 1500-year cycles in the advance and retreat of glaciers (Denton and Karlen, 1973), many studies have uncovered evidence of repeated climate oscillations of 2500, 1500, and 1000 years. During last glacial period, natural climate cycles of 1500 years appear to be persistent (Bond and Lotti, 1995) and remarkably regular (Mayewski et al., 1997; Rahmstorf, 2003), yet the origin of this pacing during the Holocene remains a mystery (Rahmstorf, 2003), making it one of the outstanding puzzles of climate variability. Solar variability is often considered likely to be responsible for such cyclicities, but the evidence for solar forcing is difficult to evaluate within available data series due to the shortcomings of conventional... |
| Tipo: Text |
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| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00233/34454/32880.pdf |
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