Estimation of local magnitude of rockbursts using strong motion accelerograms in the mines of Kolar Gold Fields

Rockbursts are minor earthquakes induced due to mining operations. The seismic signals recorded using geophones in the near field are generally saturated and are not suitable for estimating the true magnitudes. The strong-motion accelerograms recorded due to rockbursts are therefore used to obtain the Wood-Anderson synthetic seismograms for getting accurate and reliable values of the local magnitudes. Using several typical strong-motion accelerograms of rockbursts in the mines of Kolar Gold Fields, the magnitudes have been computed in the present study. Correlations of peak ground acceleration and peak ground velocity with the magnitude, studied for the rockbursts vis-à-vis the natural earthquakes in the Koyna dam area, suggest the mechanical similarity between the two different types of events. The results and findings are described in this paper.