0000000000501080
AUTHOR
Eelco J. Rohling
African monsoon variability during the previous interglacial maximum.
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 V800-yr climate disturbance in the monsoonal latitudes during the Eemian interglacial maximum (V125 ka BP). Results imply that before and after this event, the Intertropical Convergence Zone (ITCZ) penetrated sufficiently beyond the central Saharan watershed (V21n) 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 cons…
Middle-late Pleistocene eastern Mediterranean nutricline depth and coccolith preservation linked to Monsoon activity and Atlantic meridional overturning circulation
Altres ajuts: Unidad de excelencia María de Maeztu CEX2019-000940-M; Universidade de Vigo's programme to attract excellent research talent (RR04092017) The eastern Mediterranean Sea lies under the influence of high- and low-latitude climatic systems. The northern part of the basin is affected by Atlantic depressions and continental and polar air masses that promote intermediate and deep-water formation. The southern part is influenced by subtropical conditions and monsoon activity. Monsoon intensification results in enhanced freshwater discharge from the Nile River and other (now dry) systems along the North African margin. This freshwater influx into the Mediterranean Sea reduces surface w…
Reventilation Episodes During the Sapropel S1 Deposition in the Eastern Mediterranean Based on Holococcolith Preservation
Organic-rich layers (sapropels), preserved in eastern Mediterranean marine sediment records, represent pronounced perturbations to thermohaline circulation and environmental conditions in the basin, in response to enhanced African monsoon activity and subsequent massive freshwater discharge. During the most recent event, Sapropel S1 formed between 10.8 and 6.1 ka, when freshwater-driven stratification caused seafloor anoxia below ~1,800-m depth, as a result of both failure of deep water formation and enhanced productivity. Here we analyze coccolith assemblages from the open eastern Mediterranean that form a west-east transect across the basin and provide insights on past environmental chang…