Palaeoreconstruction of the Baltic Ice Lake in the Eastern Baltic - The Baltic Sea Basin - page 189

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

Jüri Vassiljev, Leili Saarse, and Alar Rosentau

Abstract 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, rep-
resented 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 north-
east 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 tim-
ing 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.

Keywords Baltic Ice Lake · Water level reconstruction · Palaeogeography

9.1 Introduction

The last termination of the Scandinavian Ice Sheet (SIS) produced a huge vol-
ume of meltwater that led to the formation of large proglacial lakes, like a Baltic
Ice Lake (BIL). BIL was first recognized by Munthe ( 1910 ) , who showed that in
the Baltic Sea basin, an ice lake dammed up during the late glacial, when the ice
margin was located at the central Swedish moraines. Later, when the ice retreated
from the central Swedish moraines, the water level dropped to the Yoldia Sea or