3D Surface Modeling of Late Pleistocene Glaciers in the Munzur Mountains (Eastern Turkey) and its paleoclimatic implications

Abstract

Located in the Eastern Anatolian Region in Turkey, the Munzur Mountains (Munzurs; 3463 m above sea level) are one of the most important glacial landscapes in Turkey, with evidence for extensive glaciations in the past and small-scale glaciation at present. As Turkey's second-largest glaciated region, these mountains include various glacial landforms, primarily glacial valleys, hanging valleys, cirques, and moraines. However, only limited data are available on the extent and chronology of former glaciations in the Munzur Mountains. This study produced data on the extent of paleoglaciers, calculated their equilibrium line altitudes (ELAs), revealed paleoclimate conditions, and modeled paleo temperatures during maximum ice extent using numerically derived reconstruction methods (GlaRe and ELA calculation tools) based on geomorphic evidence. The major glacial landforms were first mapped in detail before the reconstruction. Six hundred and eighty cirques and 30 glaciated valleys were identified. Paleoglaciers did not override the entire mountains, however, valley glaciers converged where topographic conditions were suitable.The maximum extent of glaciation covered an area of ca. 600 km 2 . The largest glacier was ca. 19 km in length. Moreover, 15 of the valley glaciers were over 10 km in length. Their average thickness was 75 m, and the maximum glacial thickness, in the Eastern Munzurs, was found to be ca. 300 m. The total volume of ice reached ca. 45 km 3 . The paleoglaciers reached as low as 1350 m above sea level. The average ELA was calculated approximately 2600 m above sea level, indicating an equilibrium line altitude depression of 1000-1100 m. The paleotemperatures, estimated based on different scenarios at the time of the maximum extent of Munzur glaciers, were 8-10 °C lower than today. The mountains experienced an increase in precipitation through this period with respect to the current precipitation scheme.