Cold event at 8200 yr B.P. recorded in annually laminated lake sediments in eastern Europe

Abstract

A quantitative annual mean temperature reconstruction from an annually laminated lake-sediment sequence in Estonia, eastern Europe, shows a distinct cold period at 8400– 8080 yr B.P. (= before A.D. 2000); the timing is consistent with that seen in the Greenland ice-core data and various high-resolution records from western Europe. During maximal cooling at 8250–8150 yr B.P., the annual mean temperature in Estonia was ∼2.0 °C colder than prior to and ∼3.0 °C colder than after the cooling. The pollen-stratigraphic and sedimentological data suggest especially cold and snowy winter conditions. The duration and amplitude of the cold event agree with the modeled impact of a sudden freshening of the North Atlantic surface water and subsequent perturbation of the thermohaline circulation. Provided that the cold event was caused by a pulse of freshwater—from the melting Laurentide Ice Sheet—to the North Atlantic, the results indicate a strong teleconnection between the North Atlantic oceanic forcing and the east European climate at least up to long 26°E, mediated probably by the changing intensity of the zonal atmospheric circulation.