|
|
|
|
|
| Crosta, X.; Romero, O. E.; Ther, O.; Schneider, R. R.. |
| Opal content and diatom assemblages were analysed in core GeoB4905-4 to reconstruct siliceous productivity changes in the eastern Gulf of Guinea during the last 40 000 yr. Opal and total diatom accumulation rates presented low values over the considered period, except during the Last Glacial Maximum and between 15 000 calendar years Before Present (15 cal. ka BP) and 5.5 cal. ka BP, the so-called African Humid Period, when accumulation rates of brackish and freshwater diatoms at the core site were highest. Conversely, accumulation rates of windblown diatoms exhibited an opposite pattern with higher values before and after the African Humid Period and greatest values during Heinrich Events, the Younger Dryas and since 5.5 cal. ka BP. Our results demonstrate... |
| Tipo: Text |
|
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00266/37699/36808.pdf |
| |
|
|
| 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 |
| |
|
|
|
