Bodies of Water Along the Coast of a Tideless Sea in Areas with Young Pleistocene Accumulation from Scandinavian Glaciers (Baltic Sea)

Abstract

Oceanographers usually investigate coastal areas in terms of how they affect various processes taking place in the sea including wave action, high tide, low tide as well as flora and fauna. On the other hand, coastal areas may also be investigated in terms of the sea affects the strip of land along the coast. This strip is often called the coastal zone (Rotnicki, 1995). Water circulation in the interior and the action of the sea both affect water systems in the coastal zone depending on geographic conditions, which may help produce temporary flooding, seawater intrusions, increased water salinity and the formation of marshes. Key geographic determinants include climate type, geological structure, relief and the resulting potamic discharge regime. Hydrography itself may also be considered a determinant. Key marine determinants include high tide, extent of high tide, short-term changes and sudden changes in sea level. Half-closed seas are a special case, which occurs in the humid climate of the northern hemisphere, where Scandinavian shelf ice used to cover the area during the Pleistocene. The Baltic Sea is a half-closed sea. The southern shore of the Baltic is made of Pleistocene and Holocene clastic sediments with varying degrees of cohesion (Tomczak, 1995). The Polish section of the Baltic coast includes sandbars (79%) with dunes between 2 and 35 m high, cliffs (18%) up to 30 m high as well as alluvial coastlines (less than 3%). These characteristics make it difficult for discharge to take place along 75% of the Polish coastline (Drwal, 1995). This results in large marshy sandbars and grassy alluvial plains with a variety of bodies of water. The virtually inland Baltic Sea is connected to the North Sea via the Straits of Denmark. This results in very small tides (15 cm) in the western part of the Baltic and even smaller tides (2 – 5 cm) in the southern part of the Baltic (Sztobryn et al., 2005). Their hydrological effects, therefore, should be negligible. In spite of this, some aspects typical of open seas may be observed along the southern Baltic coast (Drwal, 1995; Cie]linski, Drwal, 2005, Drwal, Cie]linski, 2007). The rationale for this may be found in climate conditions. Zaidler et al. (1995) argue that wind conditions resulting from pseudo-monsoon circulation characteristic