Seismic activity and flooding of hard coal mines in the Ostrava-Karvina Coalfield

The termination of mining activities often results in post-mining problems and risks. One these issues is the flooding mines. Long-term Ostrava Petrvald sub-basins Upper Silesian Coal Basin finished 1994. Tens coal seams were mined here, depth reached more than 1000 m below surface. Flooding sub-basin started flooded from one half only to prevent water into Karvina sub-basin, where continued. continual pumping has been carried out ever since. Only low-energy seismic events (up 103 J) recorded during periods pumping. high-energy event was here (108 J, magnitude 3.5, 12 December 2017). This study presents natural conditions regarding process mine flooding; induced seismicity registered mines preservation at stated level. Analysis connection presented. Probable reasons for low activity are also discussed.