Mechanism of Coal Bursts Induced by Horizontal Section Mining of Steeply Inclined Coal Seams and Application of Microseismic Multiparameter Monitoring in Early Warning

Table 1

Monitoring and warning indices and meanings.

Name of index	Formula for index	Index meanings
b value		M denotes the magnitude of an earthquake; N (≥M) refers to the number of earthquakes with the magnitude not lower than M; b reflects the level of intensity of mining-induced tremors (MITs).
Lack of shock b value		and denote the average energy level within statistical time frame and the initial energy level, respectively.
MS activity		, , and refer to the total number of tremors, the energy level, and the maximum energy level, respectively. A strong MIT appears after S value is strengthened theoretically.
Total stress equivalent		Ei, S, and T represent the energy (J) of the ith MS event within the statistical region, the area (m^2), and the statistical time (day), respectively.
Seismic tomography		and refer to the -wave velocity (m/s) at a certain point and the average wave velocity (m/s) within the inversion region, respectively.