Hydroclimatic variability during the onset of the Last Interglacial in Lake Van and Iimplications for the Eastern Mediterranean

Résumé fourni par la source

The Mediterranean region is highly sensitive to climate change and warms faster than the global average. Models forecast a pronounced drying trend, coupled with an increase in the frequency and intensity of extreme rainfall events. Past Interglacials can be used as analogues to better understand and estimate regional hydroclimatic responses to global warming.The Lake Van (Eastern Anatolia, Turkey) sediment record, ICDP site 5034, serves as a key archive to reconstruct hydrological changes in the Eastern Mediterranean. This terminal lake is the largest soda lake in the world and has experienced significant lake-level changes over Glacial-Interglacial transitions (~105 m above modern lake levels during MIS5e). Sediments covering the transition from MIS6 to MIS5e are finely laminated and, in parts, even annually laminated or varved. Therefore, these sediments enable detailed analyses of hydroclimatic variability during Termination II through XRF, microfacies analysis, stable isotope analysis, and δD on leaf wax biomarkers.Within MIS5e, first results show a significant increase in the bulk organic δ13C signal over a period of several hundred years during a stage associated with higher lake levels. This shift aligns with a change in alkenone composition and precedes a change in stratification, as suggested by a transition from varved to non-varved lithology. The external and internal drivers of these changes are further investigated by XRF core scanning, element mapping, and comprehensive biomarker analyses to explore this proxy behavior.Ultimately, the data obtained will be compared to other lacustrine records, such as the ICDP Core 5017 from the Dead Sea, to contribute to a more comprehensive understanding of regional variations in the hydroclimatic response during this warming phase in the Eastern Mediterranean.

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