African monsoon variability during the previous interglacial maximum

TitreAfrican monsoon variability during the previous interglacial maximum
Type de publicationArticle de revue
AuteurRohling, E.-J., Cane, T.-R., Cooke, Steve, Sprovieri, M., Bouloubassi, I., Emeis, K.-C., Schiebel, Ralf , Kroon, D., Jorissen, Frans , Lorre, A., Kemp, A.-E.-S.
TypeArticle scientifique dans une revue à comité de lecture
Pagination61 - 75
Titre de la revueEarth and Planetary Science Letters
Résumé en anglais

Little is known about centennial- to millennial-scale climate variability during interglacial times, other than the Holocene. We here present high-resolution evidence from anoxic (unbioturbated) sediments in the eastern Mediterranean Sea that demonstrates a sustained ∼800-yr climate disturbance in the monsoonal latitudes during the Eemian interglacial maximum (∼125 ka BP). Results imply that before and after this event, the Intertropical Convergence Zone (ITCZ) penetrated sufficiently beyond the central Saharan watershed (∼21°N) during the summer monsoon to fuel flooding into the Mediterranean along the wider North African margin, through fossil river/wadi systems that to date have been considered only within a Holocene context. Relaxation in the ITCZ penetration during the intra-Eemian event curtailed this flux, but flow from the Nile – with its vast catchment area – was not affected. Previous work suggests a concomitant Eurasian cooling event, with intensified impact of the higher-latitude climate on the Mediterranean basin. The combined signals are very similar to those described for the Holocene cooling event around 8 ka BP. The apparent type of concurrent changes in the monsoon and higher-latitude climate may reflect a fundamental mechanism for variability in the transfer of energy (latent heat) between the tropics and higher latitudes.

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