Rapid Holocene climate changes in the eastern Mediterranean
Rohling, E.J.; Casford, J.; Abu-Zied, R.; Mercone, D.; Hayes, A.; De Rijk, S.; Thomson, J.; Croudace, I.; Jorissen, F.J.; Brinkhuis, H.; Kallmeyer, J.; Wefer, G. (2000). Rapid Holocene climate changes in the eastern Mediterranean, in: Balopoulos, E.T. et al. (Ed.) International conference. Oceanography of the eastern Mediterranean and Black Sea. Similarities and differences of two interconnected basins, Zappeion international conference Centre, Athens, Greece, 23 to 26 February 1999. Research in Enclosed Seas Series, 8: pp. 339 In: Balopoulos, E.T. et al. (2000). International conference - Oceanography of the eastern Mediterranean and Black Sea: Similarities and differences of two interconnected basins, Zappeion international conference Centre, Athens, Greece, 23 to 26 February 1999. Research in Enclosed Seas Series, 8. European Commission: Brussel. ISBN 92-828-9019-8. 494 pp., more In: Research in Enclosed Seas Series. Office for Official Publications of the European Communities: Luxemburg, more |
| Authors | | Top | - Rohling, E.J.
- Casford, J.
- Abu-Zied, R.
- Mercone, D.
| - Hayes, A.
- De Rijk, S.
- Thomson, J.
- Croudace, I.
| - Jorissen, F.J.
- Brinkhuis, H., more
- Kallmeyer, J.
- Wefer, G.
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| Abstract | Preliminary results from three marine records of unprecedented hjgh resolutjon -IN68-9 from the S Adriatic Sea, LC21 from the SE Aegean Sea, and LC31 from the N Levantine Sea -show marked sea surface temperature (SST) reductions around 2600-3000,6200-6600,7400-7900, 9500-10000, 11000-12100 and 14700-15100 cal. years BP. The SST fluctuations were determined by planktonic foraminiferal ratios of warm, oligotrophic mixed layer species relative to cool, more eutrophic deep mixing indicator species. These records portray the prevalence of the seasonal thermocline, and modern distribution patterns suggest that a reasonable approximation of SST is possible. The cooling events correlate well with Holocene climate fluctuations recognised previously in the North Atlantic and the Greenland Ice Sheet. The 7400-7900 years BP event has been investigated in special detail. A temperature reduction of a few C degrees appears to have taken place abruptly within 50 years. The peak cool conditions appear to have prevailed over a period less than two centuries, after which a more gradual return to warmer conditions is found. Reestablishment of warm conditions more-or- less similar to those preceeding the cooling was completed on average two to three centuries after the onset of the cooling. An oxygen isotope record for a shallow dwelling species suggests and increase in humidity around 9000 cal BP and an onset of gradual aridification around 7000 cal BP to reach present-day conditions around 3500 cal BP, in good agreement with abundance variations of Saharan humidity markers. Further investigations are being carried out on the cores and on several new Aegean cores (in collaboration with Drs. v. Lykousis, NCMR, and C. Perissoratis, IGME, Athens). |
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