Laboratory study of elastic shocks prior to rock failure



In our previous works, the process of the occurrence of elastic shocks caused by microfracturing prior to rock failure was studied experimentally. These works provided an important suggestion for physical understanding of foreshock phenomena of earthquakes. In these previous studies, however, the number and the energy of elastic shocks originating from the whole sample, without any consideration of source locations, have been discussed. In the present paper, source locations of elastic shocks were determined in various rocks subjected to various stress systems by a new experimental technique.