Synthetic seismogram analysis of locally-recorded mine tremors

The fitting of synthetic seismograms to locally-recorded, broad-band, wide dynamic range seismic data is a very effective means of determining both seismic source parameters and focal mechanisms of mine tremors. Using data from a single three-component surface station, in conjunction with a seismic location network, a comprehensive description of the seismic source process can be obtained by the trial and error calculation of synthetic seismograms, for a point source in a homogeneous half-space, until the ground motion observed at the surface is matched. This methodology was applied to two tremors located in the Vaal Reefs Gold Mine, near Klerksdorp, South Africa, and was used to relate these events to the geological and mining situation in the environs of each hypocenter.