Source Modelling of South African Mine Tremors

摘要

McGarr et al. (1989) (1) have shown mine tremors from the Klerksdorp andCarletonville mining districts of South Africa have distinctly different spectral characteristics above the corner frequency, probably the result of preexisting deformations in the Klerksdorp region as compared to relatively simple Carletonville district structure. Spectral analysis and moment tensor inversions from the joint US Geological Survey-Phillips Laboratory 1989 field experiment suggest the Carletonville f-3 S-wave roll-off is source related. The Carletonville events exhibit doublecouple sources, with stress drops from 80 to 220 bars. Preliminary results on the Klerksdorp events confirms the lower S-wave roll-off above the corner frequencies as compared to the Carletonville events at close-in stations. Preliminary attempts at moment tensor inversions suggest a much stronger role for geology in shaping the signals from the Klerksdorp region as compared to Carletonville events. Rockbursts, Mining seismicity, Induced seismicity, Source mechanisms, Moment tensors.