Secondary deformations are ground movements occurring in areas of ceased underground mining. These are associated with delayed readjustment of rock mass resulting in subsidence, discontinuous deformations (sinks, cracks, etc.) due to destruction of underground, usually shallow, workings, and elevation of ground surface in response of rock mass to rising groundwater levels following the end of mine water drainage. Comparative analysis of secondary deformations in two former mining areas in the first period after cessation of underground hard coal mining is the subject of this study. We used ERS-1/2 and Envisat satellite radar interferometry data processed with PSInSAR technique and GIS to map vertical (in satellite’s line of sight, LOS) movements of the surface and analyse them in relation to location of coal fields and underground water table rise. In the study, two areas have been compared, the Ostrava city in the Czech part of the Upper Silesian Basin and the Wałbrzych Coal Basin in Poland. The results of analyses based on the results of PSInSAR processing between 1995 and 2000 for the Wałbrzych site indicate uplift (up to +12 mm/year) in closed parts of coal fields and subsidence (up to -8 mm/year) in areas of declining mining. Results of PSInSAR analysis over the Ostrava site indicate decaying subsidence after mine closures in the rate of up to -6 mm/year during 1995-2000. Residual subsidence and gentle uplift have been partly identified at surroundings of closed mines in Ostrava from 2003-2010 Envisat data. In Wałbrzych gentle elevation has been determined from 2002 to 2009 in areas previously subsiding. and Blachowski Jan, Jiránková Eva, Lazecký Milan, Kadlečík Pavel, Milczarek Wojciech.
The article presents an attempt at using synthetic aperture radar interferometry to determine surface displacement in a region affected by a strong earthquake induced by underground mining operations. It was assumed that the satellite radar data obtained from the Sentinel 1A/B satellites may be used to monitor induced seismicity, i.e. mining tremors. Such seismic activity is observed at much shallower depths, and the surface area affected by such activity is much more limited than in the case of natural seismic events. Research was performed in a region located in the southwest part of Poland, where copper ore is extracted using underground methods. The geological structure of the selected area increases the likelihood of induced seismic events. Moreover, the area is one of the most seismically active regions in this part of Europe. The tremor analysed in this paper occurred on November 29, 2016, and had a magnitude of Mw4.2. Calculations showed that the seismic event resulted in the creation of a 2.7 km x 2.5 km subsidence basin. The paper demonstrates that it is possible to use data provided by the Sentinel 1A/B satellites to detect surface displacements caused by a mining tremor.