Strong Mining-Induced Seismicity Characteristics and Precursor Signals Based on Statistical Seismology

Abstract

As a consequence of the ongoing expansion of coal mining operations in China, the geological conditions encountered in these operations have become increasingly complex. Mining-induced seismicity is a frequent occurrence, resulting in significant economic losses. A total of 12,000+ mining-induced seismic events have been recorded during deep coal mining in the Ordos Mining Area. This study examines the distribution pattern of mining-induced seismicity and analyzes the aftershock attenuation and seismic migration patterns of mining-induced seismic events based on typical mining-induced seismic sequences. The findings demonstrate that the modified Omori law offers a clear description of the decay pattern of aftershocks triggered by strong mining-induced seismicity. Over time, the magnitude and frequency of the aftershocks exhibit a decay pattern consistent with a t−p law. The power law GR relationship is applicable to the mining-induced seismic sequence. In advance of a strong mining-induced seismicity, the b-value will decline below the norm (1.0–1.1) and the number of microseisms will rise markedly, indicating the commencement of the nucleation phase. Such signals may be regarded as an indicator of an impending strong mining-induced seismicity. The seismic migration rate in the Ordos Mining Area, which is influenced by the geological environment, has been observed to be relatively stable at approximately 65 m/day. The mining-induced seismic migration and diffusion laws provide a theoretical explanation for the phenomenon of coordinated fracture of overlying key strata.