Seismicity in Mines

Recent seismological research has focused on processes other than pure shear failure (double-couple) as an alternative mechanism for some types of seismic events. This has been stimulated by what appears to be anomalous focal mecha­ nisms observed for several earthquakes of possible volcanic nature in the 1980 Mammoth Lakes, California sequence (JULIAN and SIPKIN, 1985; SIPKIN, 1986). Although stu...