Seismic Signature of the Caving Process

Abstract

The four seismic catalogues analysed in this chapter contain range from a couple of thousand events right up to a couple of hundred thousand events. The four seismic data sets are not only consistent as separate input catalogues, but also as a whole. The mines in question are not only using the same seismic system in the recording of the seismicity but the recorded data was subsequently processed using the same version of the software. Because of this the input data available was not only in sufficient quantity but also quality. I used two types of parameters in analysing the presented data. The first is based on the mining data and the second is derived from seismicity. By definition, the seismicity that I was analysing is mine-induced seismicity. The definition implies that there is a strong relationship between the mining activities and seismic parameters. This relationship is certainly there but it is not continuous in its nature, nor is it constant. As I have illustrated, an increase in production rates will not always result in an increase of the seismicity rates or in larger size seismicity taking place. The dependency between production and seismicity changes over time due to the progress of the caving process. The seismicity parameters that I have used are based on seismic moment and seismic energy, which are independent of each other. I have also used the locations of the seismicity as well as the rates. It is obvious that the seismicity rates, their locations and source parameters are independent of each other, and thus provide discrete results. The presented seismic data analysis and interpretation resulted in a description of precise and detailed seismic response to the caving process.