Microseismic Investigations in Coal Mines.
Leighton-FW; Steblay-BJ; Hooker-VE
Am Min Cong J 1974 Oct; 10(60):66-71
Rock noises were monitored in a deep western Colorado coal mine and include data preceding several bounces (release of seismic energy large enough to be damaging or felt by nearby personnel) of varying magnitudes. Techniques were developed to locate and delineate bounce areas. These data indicate that microseismic techniques may be used to establish where and when coal mine bounces will occur. Microseismic equipment was also used to monitor a controlled roof fall experiment. This equipment detects microseismic noises of ultrasonic frequencies and translates these frequencies down to the audible range. This minimizes background noise. Results of this initial experiment indicate that the peak buildup of rock noise occurred about 15 minutes prior to roof failure.
Am. Min. Cong. J., V. 10, No. 60, October 1974, PP. 66-71