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 productDynamic 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.

Review of Works Combining GNSS and InSAR in Europe

“…In Portugal, instead, only two scientific contributions have been reported in connection to the subsiding area of Lisbon [70,104]. Eastern Europe shows a widespread distribution of land subsidence issues, which have been analyzed by combining GNSS and InSAR data, in the coastal portion of Lithuania, close to Kaszuby Lakeland [105], in the agglomeration of Warsaw, Poland [106], in the Bucharest metropolitan area in Romania [107,108], and close to the Tatra Mountains in Slovakia [109]. A specific focus on mining-induced land subsidence events and collapses was provided by research which studied the Upper Silesia Coal basin, covering a part of the territory of Poland [110] and the Czech Republic [111].…”

“…Case studies were identified in Netherlands, such as surface deformation analyses performed over the whole national territory [176][177][178][179] or monitoring works of the water defence structure of Waddenzee and IJsselmeer [180,181]. Two other scientific contributions focused on the Polish and Lithuanian Baltic coastal areas [105] and the surface displacement pattern affecting the permafrost areas in northern Norway [75].…”

Numerical model of late Pleistocene and Holocene ice-sheet and shoreline dynamics in the southern Baltic Sea, Poland

“…Adjacently, in the north, a virtually nontidal, semi-saline reservoir of the Baltic Sea with an average water depth of approximately 55 m connects with the North Sea through the Danish straits, limiting the water exchange with the ocean. Within the SBS coast, poorly consolidated (soft-rock) moraines, sandy spits, and lowlands predominate and are characterised by near-zero (or slightly negative) vertical crustal displacements (Graniczny et al, 2015). Trends driven by climate change have been stable since the Littorina transgression (approx.…”

“…Within the predictive part of the 4F model, similar to the work of Meyer (2003), scenarios of future shoreline changes were analysed based on three main components: DEM, eustatic sea-level changes, and influence of isostasy. Contrary to Meyer (2003), in the case of Polish coasts, the trend of crustal changes due to isostasy is near zero (or slightly negative), depending on the exact location (Graniczny et al, 2015). Therefore, acknowledged impacts were excluded from the model as being negligible.…”

An Analysis of Vertical Crustal Movements along the European Coast from Satellite Altimetry, Tide Gauge, GNSS and Radar Interferometry

“…The PSI deformation value should be predicted at the location of the GNSS stations. Every location is different, and complex deformation phenomena may occur; however, an assessment of each station is possible [68]. In this article, vertical motion in GNSS stations was calculated based on various view geometries and viewing angles.…”