An unusual mid-Pleistocene monsoon period over Africa and Asia

M. Rossignol-Strick (), M. Paterne, F. C. Bassinot, K.-C. Emeis and G. J. De Lange
Additional contact information
M. Rossignol-Strick: Laboratoire de Paléontologie et Palynologie
M. Paterne: Centre des Faibles Radioactivités, Laboratoire mixte CNRS-CEA, Domaine du CNRS
F. C. Bassinot: Centre des Faibles Radioactivités, Laboratoire mixte CNRS-CEA, Domaine du CNRS
K.-C. Emeis: Institut fur Ostseeforschung Warnemuende
G. J. De Lange: Institute of Earth Sciences, Utrecht University

Nature, 1998, vol. 392, issue 6673, 269-272

Abstract: Abstract During the Quaternary period, organic-rich black layers called sapropels were intermittently deposited in the deep eastern Mediterranean Sea1,2 following high flood periods of the Nile River3. During the past 250 kyr, timing of sapropel formation coincides with astronomically driven maximum summer insolation in the northern tropics4. The insolation variations — described by a monsoon index4 — modulate the intensity of the African monsoon feeding the Nile flood4. Here, we report the observation of a thick sapropel in eastern Mediterranean sediments that conspicuously deviates from the usual pattern. The sapropel, dated at 528–525 kyr by astronomical tuning of the stratigraphic oxygen-isotopic record, is anomalous because the tropical summer insolation, while at a peak at this time, was much lower than during the deposition of the more recent sapropels. The Mediterranean climate was cold and dry, at least at sea level. At the same time, in the equatorial Indian Ocean there was an extreme event of low surface-water salinity caused by heavy monsoonal fluvial discharge5. The simultaneity, within dating uncertainties, of unusually heavy monsoon rainfall over Africa and Asia while summer insolation (and the monsoon index) was relatively low indicates a large, regional-scale monsoon anomaly that cannot be explained in terms of current understanding of astronomical forcing.

Date: 1998
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/32631 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:392:y:1998:i:6673:d:10.1038_32631

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/32631

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().