Changes in the frequency-energy distribution of seismic events during mining in the Ostrava-Karvina coal field

The relation between the number of seismic events N and their magnitude and /or energetic magnitude is one of the basic relations in the Statistics of earthquakes and mining-induced events, A derailed analysis of the b-values in the relation log N = a - b log E for the induced seismic events occurrin g in the Ostrava-Karvina Coal Basin is given in this paper The least-square s method as well as the maximum likelihood method were applied in solving t his problem mathematically. Based on the results of frequency-energy distri bution analysis, it was proved that the variations of b-values in space and time do exist, and that these values are inversely proportional to the lev el of induced seismicity influenced by the various mining activities being carried out in-situ. This statement could, in general, be supported by the fact that lower b-values correspond to higher seismic activity, while highe r b-values correspond to low and moderate seismic activity.