9. Palaeoreconstruction of the Baltic Ice Lake in the Eastern Baltic

A GIS-based palaeogeographic reconstruction of the development of the Baltic Ice Lake (BIL) in the eastern Baltic during the deglaciation of the Scandinavian Ice Sheet is presented. A Late Glacial shoreline database containing sites from Finland, NW Russia, Estonia, Latvia and modern digital terrain models was used for palaeoreconstructions. The study shows that at about 13,300 cal. years BP the BIL extended to the ice-free areas of Latvia, Estonia and NW Russia, represented by the highest shoreline in this region. Reconstructions demonstrate that BIL initially had the same water level as the Glacial Lakes Peipsi and Võrtsjärv because these water bodies were connected via strait systems in central and northeast Estonia. These strait systems were gradually closed at about 12,700–11,700 cal. years BP due to isostatic uplift, prior to the final drainage of the BIL. Glacial Lake Võrtsjärv isolated from the BIL at about 12,400–12,000 cal. years BP. Exact timing of Glacial Lake Peipsi isolation is not clear, but according to the altitude of the threshold in northeast Estonia and shore displacement data, it was completed at about 12,400–11,700 cal. years BP.