The evolution of the southern Baltic coastal zone

This article discusses the formation and evolution of the coastal zone of the southern Baltic from the decay of the last Scandinavian ice-sheet, which took place some 14 ka BP. During the first 4 ka, the shores of the then southern Baltic basins were shaped under the dominant influence of considerable variations in water level and the young, post-glacial topography emerging from under the ice. Later, until the beginning of the Atlantic transgression, the shores were also unstable, because sea level changes resulting from periodic connections with the World Ocean followed one another in rapid succession. Since that transgression destroyed much of the former shoreline, its reconstruction is at best highly problematical, and in some places no longer possible. The maximum range of the Litorina Sea gave rise to a coastal zone that in many places is to this day quite conspicuous in the local topography and sediments. During the last 4 ka, the shoreline has changed relatively little, thus the present shoreline is largely redolent of the original one. In the coming 100 years or so, the abrasion of the cliffs along the southern Baltic shore will probably accelerate, as will the retrogradation of certain sections of the shoreline, with the result that the shoreline will be less of a straight line than it is at present. Land up to a height of 1 m above sea level will be inundated. The greatest changes in the lie of the shoreline are to be expected in the River Wisła (Vistula) delta and around the Zalew Szczeciński (Oderhaff, Szczecin Lagoon).