African monsoon variability during the previous interglacial maximum

Research areas:
Year:
2002
Keywords:
Eemian
Authors:
  • E. -J. Rohling
  • T. -R. Cane
  • S. Cooke
  • M. Sprovieri
  • I. Bouloubassi
  • K. -C. Emeis
  • D. Kroon
  • Frans Jorissen
  • A. Lorre
  • A. -E. -S. Kemp
Journal:
Earth and Planetary Science Letters
Volume:
202
Number:
1
Pages:
61 - 75
Month:
2002
ISSN:
0012-821X
BibTex:
Abstract:
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{\textdegree}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 {\textendash} with its vast catchment area {\textendash} 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.