ABSTRACT
To assess the location of seismic hazard zones in roof strata, the passive velocity tomography was used. In each 3-months time period calculations were performed for about 70 seismic events recorded by 16 seismic stations. The area of study was 1000 m by 700 m. The zones of high values of P-wave propagation velocity, not more than 12 % higher than the average value of 4000 m/sec, have been found to correlate with the distribution of large seismic tremors. The energy of the strongest tremor was 4 × 107 J (local magnitude 3.1). That tremor induced a rockburst at the coalface No. N-303/507 of the Bielszowice coal mine.
