The article considers the problem of correct seismic hazard assessment in mining regions where actual macroseismic model may differ from common variant. To show it we have summarized macroseismic manifestations of modern earthquakes occurred near mine areas of the Urals for last two decades. The matter under consideration is a set of 15 induced and natural earthquakes of relatively small magnitudes (M = 1.7–4.4) that have been sensed on the surface with intensity up to 5 points of MSK-64 scale. Analyzing the data in terms of Shebalin-Blake model (I = 1.5M_LH – a lg(r) + b) we have shown all seismic sources may be divided into two groups. Macroseismic effects for events in every group may be specified by different coefficients set that depends on source depth. Deep sources (depth more than 1 km) radiating energy generally via body waves demonstrate model parameters (a = 3.5 и b = 3) that do not differ from those stated earlier for Eastern-European plate, Urals and Western Siberia [11]. The group of near surface events are approximated with coefficients a = 2.7 and b = 1.2, that describe adequately seismic energy propagation with surface waves. Generalization of macroseismic data extended the range of model applicability significantly by lowering both magnitudes and hypocentral distances. A new macroseismic equation allows to calculate seismic intensity more accurately and estimate seismic hazard correctly especially in the task of detailed seismic zonation.

Keywords

Induced earthquake, macroseismic effect, macroseismic equation, Shebalin-Blake model, magnitude, intensity, seismic hazard.