Some results on the accuracy of the location of mining-induced seismic events: Experience of French coal mines

In French coal mines large-scale seismic networks have been implemented to monitor areas prone to rockburst. The knowledge of the hypocenters of induced seismic events is absolutely necessary for further analysis of seismic activity. This concerns also the relation with mining geometry, focal mechanisms etc. So, at present, much research work is carried out to improve the accuracy of location. The paper presents some results related to this topic emphasizing two points: the geometry and the scale of the seismic network which are important with respect to depth location, the appropriate choice of the wave propagation model the quality of which has great influence on the accuracy of the obtained location. At present, with large-scale seismic networks (some kilometers) the accuracy of the location of the events may reach 100 meters at the best.