Microseismicity is an generated elastic wave when a crack is generated due to deformation or damage of a material, and it tends to increase sharply before macro-failure of the material. It can be used to monitor the safety of the rock mass structure such as mine and tunnel etc., and also used to determine the locations of cracks or macro-failures. In order to analyze the source location of cracks, it is important to consider the elastic wave propagation velocity, arrival picking, source location analysis algorithm, and sensor array. However, the location of the sensor may be restricted due to site conditions and economic problems, which may result in inability to interpret the source location or decrease reliability of MS monitoring. In this study, to improve the accuracy of source location analysis, we analyzed source locations according to various arrival picking method and source location algorithm. Among the methods, AIC and Generic algorithm for source location were found to be superior to other methods.
Microseismicity(or Microseismic event) can be defined as a very small earthquake caused by natural(wave, wind etc.) or artificial (hydraulic fracturing, blasting etc.) causes. Generally, it is a small size (< M_w 2.0) and high frequency (> 50Hz) compared to earthquakes. Earthquakes are primarily caused by nature, but microseismic event is often caused by induced earthquakes. Figure 1 is a brief summary of the frequency domain and the audible domain for earthquakes, microseismic event, and acoustic emissions. Microseismicity is an generated elastic wave when a crack is generated due to deformation or damage of a material, and it tends to increase sharply before macro-failure of the material. Microseismic monitoring can be traced back to 1938 when the U.S. Bureau of Mines attempted to relate seismic wave velocity with pillar load. It is used for geotechnical safety monitoring based on the characteristics of the increase in the number of events before major failures. Thesedays in situ microseismic monitoring of the rock mass fracturing process has been widely used in rock mechanics tests and rock engineering projects throughout the world
