Glacier response to the change in atmospheric circulation in the eastern Mediterranean during the Last Glacial Maximum

• LGM glacier oscillations are documented between 20.4 ± 1.2 and 18.6 ± 1.2 ka.
• Two older glaciations are geomorphologically well constrained, but not yet dated.
• The older Lateglacial advance occurred not later than 15.9 ± 1.1 ka.
• The younger Lateglacial advance is attributed to the Younger Dryas.
• These fluctuations are correlated to changes in atmospheric circulation patterns.

In this study, we document glacial deposits and reconstruct the glacial history in the Karagöl valley system in the eastern Uludağ in northwestern Turkey based on 42 cosmogenic 10Be exposure ages from boulders and bedrock. Our results suggest the Last Glacial Maximum (LGM) advance prior to 20.4 ± 1.2 ka and at least three re-advances until 18.6 ± 1.2 ka during the global LGM within Marine Isotope Stage-2. In addition, two older advances of unknown age are geomorphologically well constrained, but not dated due to the absence of suitable boulders. Glaciers advanced again two times during the Lateglacial. The older is exposure dated to not later than 15.9 ± 1.1 ka and the younger is attributed to the Younger Dryas (YD) based on field evidence. The timing of the glaciations in the Karagöl valley correlates well with documented archives in the Anatolian and Mediterranean mountains and the Alps. These glacier fluctuations may be explained by the change in the atmospheric circulation pattern during the different phases of North Atlantic Oscillation (NAO) winter indices.