DBPapers
DOI: 10.5593/SGEM2015/B13/S5.114

INDUCED SEISMICITY AND SEISMIC HAZARD IN MINING REGIONS

R. Dyagilev
Friday 7 August 2015 by Libadmin2015

References: 15th International Multidisciplinary Scientific GeoConference SGEM 2015, www.sgem.org, SGEM2015 Conference Proceedings, ISBN 978-619-7105-33-9 / ISSN 1314-2704, June 18-24, 2015, Book1 Vol. 3, 879-886 pp

ABSTRACT
Traditionally common methods of seismic hazard assessment take into account only natural earthquakes. As result the main efforts of scientists in problem of seismic zoning are aimed to zoning factors and conditions that raise the probability of strong tectonic earthquakes. Such approach is obviously correct if the natural seismicity is dominant. But there are some regions of low or moderate tectonic seismic activity where contribution of induced earthquakes as well as nontectonic seismic events may be comparable to natural one or even prevail. The main factors composing induced seismicity are exploration of deposits (oil and gas extraction, open-cast and underground mining), hydraulic structures (dams, reservoir, power stations), underground storage of waste or gas etc. There is no doubt that influence of most kinds of human activity on seismicity is well known, so many preventing measures are taken to minimize possible negative sequences. Unfortunately they are not always successful and possible seismic effect may be very serious. Therefore an estimation of seismic hazard due to induced sources for such regions is important not less than due to natural ones.
We have tried to estimate the contribution of induced earthquakes occurring in the Urals that is the region of moderate seismic activity, where hundreds of deposits of different mineral types are under exploration. To obtain reliable result we followed the idea of probabilistic-deterministic forecasting of dangerous seismic processes according to methodology offered by V.I. Ulomov [8] that have become common in Russia and other countries since the end of XX century. To estimate an actual seismic hazard the data set of hundreds of earthquakes happened during recent decades in main mining districts of the Urals was used. Including macroseismic information it has become the base for development of two prognostic models: the model of origination of seismic source zones and the model of the seismic effect generated by them. Both models are absolutely different from analogic ones elaborated earlier for natural seismicity [8], [9], [10]. New maps calculated in terms of seismic intensity and peak ground acceleration show the actual level of seismic hazard due to induced seismicity that happen at the date and take into account the plans of deposits exploration for nearest hundred years.

Keywords: induced seismicity, seismic hazard assessment, seismogenerating zone, macroseismic equation, Urals