PAGEOPH, Vol. 139, No. 3/4 (1992) 0033-4553/92/040697-23$1.50 + 0.20/0 9 1992 Birkh~iuser Verlag, Basel Mining-induced Microseismicity: Monitoring and Applications of Imaging and Source Mechanism Techniques R. P. YOUNG, t S. C. MAXWELL, ~ T. I. URBANCIC I and B. FEIGNIER l Abstract--The study of microseismicity in mines provides an ideal method for remote volumetric sampling of rock masses. The nature and uniqueness of microseismic monitoring is outlined in the context of acquisition hardware and software requirements. Several topics are used to highlight the potential for novel applications of microseismicity and to outline areas where further study is required. These topics reflect some of the current interest areas in seismology, namely b values and source parameters, fault-plane solutions, modes of failure and moment tensor inversion, imaging and seismicity- velocity correlations. These studies suggest potential correlations between zones of high seismic velocity, high microseismic activity and maximal stress drops, which can be interpreted spatially to be the locations of highly stressed ground with a potential for rock bursting. Fault-plane solutions are shown to be useful in determining the slip potential of various joint sets in a rock mass. Source parameter studies and moment tensor analysis clearly show the importance of non-shear components of failure, and b values for microseismicity appear to be magnitude-limited and related to spatial rather than temporal variations in effective stress levels. Key words: Induced seismicity, tomography, b values, source parameters, moment tensor inversion. Introduction Seismological techniques provide information on rock properties, stresses, frac- tures and mechanisms of failure for all those areas where seismic events are generated (source effects). In addition, seismic travel time and amplitude can be used to determine the nature of the rock between the source and the detector (path effects). Rockbursts are mining-induced seismic events, usually in the magnitude range M 1.5 to 4.5 which result in dynamic failure of the rock mass, and in the worst case, can cause loss of life and mine closure. The sequence of excavation in underground mines leads to a redistribution of in situ stress and can in some cases result in a rockburst. Low-magnitude mining-induced microseismic events (-4 < M < 0), usually cause no major structural damage in a mine, but are the ~ Engineering Seismology Laboratory, Department of Geological Sciences, Queen's University, Kingston, Ontario, Canada.