Late Pleistocene and Holocene Glacier Extent in the Georgian Caucasus

摘要

This article presents the information of the Georgian Caucasus glaciation at the Late Pleistocene and Holocene period (～126,000-11,700 calendar years ago). Our primary aim was to numerically reproduce the ice extent deduced from geological and geomorphological mapping. We used the analog method with the 30 m resolution SRTM DEM (Shuttle Radar Topography Mission Digital Elevation Model). In addition, the rates of glaciation of those times are identified based on the stadial moraines and erratic boulders. The current investigation has revealed that in the Late Pleistocene, the central and western Caucasus characterized the highest glaciation, while the eastern Caucasus boasted the lowest glaciated area, and in the southern Georgia’s highland glaciation has almost the same form as there is in the Eastern Caucasus today. The longest glaciers were located in the Enguri (Nenskra ～36 km, Mulkhura ～35.1 km, Dolra ～34.5 km), Kodori (Sakeni ～25 km, Klichi ～20 km, Marukhi ～17.3 km) Rioni (Buba ～23 km, Kirtisho ～20.5 km, Jejora ～17.5 km) and Tergi (Devdoraki ～38.5 km, Suatisi ～32 km) river basins. We found, that topography thresholds related to the elevation and hypsometry of individual catchments controlled the gradient of the rate of glacier expansion in the domain at that time.