Climatic change recorded in the sediments of the Chew Bahir basin, southern Ethiopia, during the last 45,000 years

Abstract

East African paleoenvironments are highly variable, marked by extreme fluctuations in moisture
availability, which has far-reaching implications for the origin, evolution and dispersal of Homo sapiens
in and beyond the region. This paper presents results from a pilot core from the Chew Bahir basin in
southern Ethiopia that records the climatic history of the past 45 ka, with emphasis on the African
Humid Period (AHP, w15e5 ka calBP). Geochemical, physical and biological indicators show that Chew
Bahir responded to climatic fluctuations on millennial to centennial timescales, and to the precessional
cycle, since the Last Glacial Maximum. Potassium content of the sediment appears to be a reliable
proxy for aridity, showing that Chew Bahir reacted to the insolation-controlled humidity increase of
the AHP with a remarkably abrupt onset and a gradual termination, framing a sharply defined arid
phase (w12.8e11.6 ka calBP) corresponding to the Younger Dryas chronozone. The Chew Bahir record
correlates well with low- and high-latitude paleoclimate records, demonstrating that the site
responded to regional and global climate changes.

• african humid period
• chew bahir
• climatic history
• east africa
• lake sediments
• palaeoclimate
• paleoclimate
• southern ethiopia

Resources

• Foerster_etal_2012_CLimatic_Change_Sediments_Chew_Bahir.pdf
• http://www.sciencedirect.com/science/article/pii/S104061821200448X

Bibliography

Foerster, V., Junginger, A., Langkamp, O., Gebru, T., Asrat, A., Umer, M., Lamb, H. F., Wennrich, V., Rethemeyer, J., Nowaczyk, N., Trauth, M. H., Schaebitz, F. (2012): Climatic change recorded in the sediments of the Chew Bahir basin, southern Ethiopia, during the last 45,000 years. – In: Quaternary International, Vol. 274, p: 25-37