Discrimination of blasts in mine seismology

Seismic monitoring systems installed in mines record seismic signals from various dynamic processesfracturing in rock mass, production and development blasts, impacts and vibration of machinery, etc.It is important to classify the recorded seismic events before doing most kinds of analysis of seismic data.For instance, the assessment of seismic hazard or analysis of rock mass stability requires only events associated with fracturing in rock mass.A discrimination technique developed in global seismology was adopted for mining environments in order to identify blasts.The technique utilises a set of seismic event characteristics (time of occurrence relative to blasting time, radiation pattern, distribution of seismic energy between low-and high-frequency bands, correlation of the seismic signals with the preceding and succeeding waveforms) and quantifies a probability that a particular event belongs to a population of blasts.The application of the technique to several mines is discussed.'normal'.