New insights into the termination of the African Humid Period (5.5 ka BP) in central Ethiopia from detailed analysis of a diatom record
Focus sur la fin de la période humide africaine en Éthiopie centrale (5,5 ka BP) par l'analyse détaillée de diatomées fossiles
Roubeix, V. ; Chalié, F.
Type de document
Article de revue scientifique à comité de lecture
Affiliation de l'auteur
IRSTEA AIX EN PROVENCE UR RECOVER FRA ; CEREGE AIX EN PROVENCE FRA
Résumé / Abstract
The termination of the African Humid Period in northern Africa has been described as abrupt, occurring within centuries, as well as gradual, in response to incremental decreases in summer insolation. This study examined the rapidity of the change in diatom assemblages over the period from 6.5 to 4.5 cal ka BP, in a core studied previously at a coarser resolution. This transition was characterized by high variability of assemblages, which could be related, in part, to changes in water conductivity, and potentially enhanced by a site-specific hydrological threshold or ecological salinity threshold. We hypothesize that the variations in diatom assemblages reflect climate fluctuations, which may have been an early warning signal of an impending climate regime shift.
Journal of Paleolimnology, p. 1 - 12