Graniczny, M., Čyžienė, J., van Leijen, F., Minkevičius, V., Mikulėnas, V., Satkūnas, J., Przyłucka, M., Kowalski, Z., Uścinowicz, Sz., Jegliński, W., Hanssen, R.
Vertical ground movements in the Polish and Lithuanian
Baltic coastal area as measured by satellite interferometry
Abstract. The article contains results obtained from realization of the Polish and Lithuanian
Baltic case study within the EU – FP 7 SubCoast project, which one of the
primary aims was analysis of vertical ground movements, potentially causing
geohazards in the coastal areas. To reach this goal Interferometric Synthetic
Aperture Radar (InSAR) data were obtained. For the Polish and Lithuanian Baltic
coast ERS archive radar data were processed in order to provide Permanent
Scatterer (PSInSAR, PSI) results that
were then used to create the new innovative product – Dynamic DEM (DDEM). The
deformation model defined by the SubCoast project normally needs to be created
by merging InSAR, satellite navigation (GNSS), optical leveling and/or
gravimetry measurements. Elaboration of DDEM enables more effective comparison
between PS and tectonic features. Comparison of PS time series with groundwater
changes shows a direct correlation, confirming impact of groundwater on
subsidence or uplift of the ground surface. The results of the geological
interpretation demonstrated that the examples of movements detected by PSI
include subsidence linked to deformation of engineering constructions,
compaction of organic or weak soils, and eolian accumulation or deflation
processes of the sand dunes. For the Polish and Lithuanian coasts most of the
area proved to be stable, nevertheless some local deviations up to –15 mm per
year of movement were found.