Geochemical sediment core data (KK 12-1 and KK 12-2) covering 31 kyrs from Lake Karakul, Tajikistan

To examine glacial-interglacial hydrological changes in the region, we analysed geochemical parameters of a 31-kyrs record from Lake Karakul and performed a set of experiments with climate models to interpret the results. δD values of terrestrial biomarkers showed distinct insolation driven trends reflecting major shifts of water vapor sources.

For aquatic biomarkers, positive δD shifts driven by changes in precipitation seasonality, were observed at ca. 31-30, 28-26, and 17-14 kyrs BP. Multi-proxy paleoecological data and modelling results suggest that increased water availability, induced by decreased summer-evaporation, triggered higher lake levels during those episodes, possibly synchronous to Northern Hemispheric rapid climate events. We conclude that seasonal changes in precipitation-evaporation-balance significantly influenced the hydrological state of a large waterbody such as Lake Karakul, while annual precipitation amount and inflows remained fairly constant.