Geological Hazard Potential at the Baltic Sea and Its Coastal Zone: Examples from the Eastern Gulf of Finland and the Kaliningrad Area - The Baltic Sea Basin - page 349

damage should be considered, for example, in the towns of Pionersky, Svetlogorsk,
and Otradnoye.
16.4.2.4 Aeolian Processes
Aeolian processes have an exogenic hazard potential only within the areas of the
Curonian and Vistula spits. The most hazardous are the “blowing craters” in fore-
dunes, especially if these craters go through the entire dune system. In 2005, along
the marine coast of Curonian Spit, 170 blowing craters were observed (Zhamoida
et al. 2009 ; Fig. 16.3 ) .
16.4.2.5 Flood and Swamping
The lowlands of the continental coasts of the Curonian and Vistula Lagoons suf-
fer from floods and swamping (Fig. 16.3 ) . For example, within the Neman Delta
Lowland, some areas are located up to 1.5 m below sea level. The geological struc-
ture and the tectonic regime (long-time subsidence) lead to the storage of great
amounts of groundwater close to the land surface and their inactive discharge.
Together with the periodical sea-level rising in the Curonian Lagoon and the Neman
River water supply, these factors lead to floods which sometimes cut off roads and
leave the coastal villages without connection to the “mainland.”
16.5 Eastern Gulf of Finland
16.5.1 Endogenic Processes
The potential hazard of endogenic processes in the eastern Gulf of Finland is ques-
tionable. According to Yaduta ( 2002 , 2003 ) , the area is characterized by local
differentiations in trends and rates of sea bottom and land surface uplift and sub-
sidence. Possibly, this is a result of the most recent tectonics of the so-called
key type, where different hard rock blocks move in various directions under the
control of a fault system. The recent study carried out by Assinovskaya and
Novozhilova ( 2002 ) indicates signs of seismic activity within the Gulf of Finland
and adjacent areas. These zones are traced from the territory of Finland through the
Russian part of the gulf and its coastal zone. Connection to recent tectonic move-
ments (Dvernitsky 2009 ) is particularly important for planned skyscriber projects
in St. Petersburg, where the upper part of the geological sequence is represented
by Quaternary deposits with unfavorable geotechnical properties. The other fault-
related aspect of geological risk assessment is related to radon emission along those
faults (Dvernitsky 2007 ) .
VSEGEI side-scan sonar investigations carried out in the Vyborg Bay of the
Gulf of Finland in 2008 detected several concentric structures (up to 10-15 m diam-
eter) at the sea bottom in the area of known tectonic faults (Fig. 16.6 ) . Morphology