S031

The Khibiny Mountains is a highly stressed large alkaline intrusion of the Paleozoic characterized by a variety of tectonic structures. In the massif area Kirovsk Branch of Apatit Joint Stock Company and North-Western Phosphorus Company are developing apatite-nepheline ore deposits by underground and open pit technologies. Mining in tectonically loaded rocks may lead to the of induced seismicity. In underground mines under the influence of high rock pressure, the continuity of the rock is disrupted. This manifest itself in dynamics as shelling and shooting of rocks, the dynamic stabbing, tremors, micro- and rockbursts and induced earthquakes. As in the case of tectonic seismicity, induced earthquakes can trigger aftershocks (aftershocks). In mining, industrial explosions can also trigger aftershocks.

Using long-term data on the seismicity of the Khibiny massif, it was shown that the distances from seismic events to their triggers (other earlier seismic event) obey a power-law distribution with a parameter that does not depend on the trigger magnitude. Felzer, Brodsky (Nature, V. 441, 2006) and Richards-Dinger et al. (Nature, V. 467, 2010) previously revealed that the same distribution is appropriate for tectonic seismicity. In addition, in this study we showed that in the Khibiny Mountains the distribution of distances from seismic events to the triggering explosions is also power law. Thus, the power law for the spatial distribution of postseismic and post-blasting activities is also valid under conditions of technogenic seismicity. The same type of distribution for postseismic and post-blasting activities in the Khibiny allows to believe that the spatial distribution is determined by the rock properties and does not depend on the mechanism of its disturbance (seismic event or explosion).

Combining a power-law pattern and the previously established earthquake productivity law, confirmed for induced seismicity and seismic productivity of explosions, allows us to estimate the zone where aftershocks are expected with a given probability.

This research was supported by RFBR, project Nu 19-05-00812.