Lack of marine entry into Marmara and Black Sea-lakes indicate low relative sea level during MIS 3 in the northeastern Mediterranean

Abstract. The Marine Isotope Stage3 (MIS 3) is considered a period of persistent and rapid climate and sea levelvariabilities during which eustatic sea levelis observed to have varied by tens of meters. Constraints on local sea levelduring this time are critical for further estimates of these variabilities. We here present constraints on relative sea levelin the Marmara and Black Sea regions in the northeastern Mediterranean, inferred from reconstructions of the history of the connections and disconnections (partial or total) of these seas together with the global ocean. We use a set of independent data from seismic imaging and core-analyses to infer that the Marmara and Black Seas remained connected persistent freshwater lakes that outflowed to the global ocean during the majority of MIS 3. Marine water intrusion during the early MIS-3 stage may have occurred into the Marmara Sea-Lake but not the Black Sea-Lake. This suggests that the relative sea levelwas near the paleo-elevation of the Bosporus silland possibly slightly above the Dardanelles paleo-elevation, ~80 mbsl. The Eustatic sea levelmay have been even lower, considering the isostatic effects of the Eurasian ice sheet would have locally uplifted the topography of the northeastern Mediterrranean.