Microseismic activity and subsurface structural characteristic of the Laohutai coal mine in Northeast China based on a linear dense seismic array

Abstract

Abstract The microseismic activity and subsurface structures are critical for assessing potential seismic hazards and improving mining safety. However, due to the limitations of the seismic stations in the Laohutai coal mine area, the characteristics of the complex microseismic activity and subsurface structure remain debated and poorly understood. In this study, we deployed a new linear dense seismic array in the Laohutai coal mine, and detected 324 new microseismic events by applying the Match and Locate method. The double-difference relocation results show that the microseismic events are mainly distributed around the sub-faults of the Laohutai coal mine at depths of ~ 0.2–1.5 km and gradually migrate toward the coal mine over time. In addition, we constructed ambient noise tomography to further investigate the subsurface structure of the coal mine. The tomographic results indicate that the shear-wave velocity structure is well-correlated with the subsurface tectonics. The microseismic activities are more likely to occur near the high-velocity zone after a minor stress disturbance, suggesting that the microseismic activities may be associated with the characteristic of the subsurface structure. The relationship between microseismic events and the subsurface structures contributes to the understanding of seismic behavior in coal mines and provides valuable insights into mine exploration. Graphical Abstract

Keywords

• Laohutai coal mine
• Dense seismic array
• Microseismic activities
• Double-difference relocation
• Shear-wave velocity