Study on Characteristics of Mining Earthquake in Multicoal Seam Mining under Thick and Hard Strata in High Position

Table 1

Statistical table of mining earthquake by energy level.

Coal seam	Energy (J)
	10^2∼10^3	10^3∼10^4	10^4∼10^5	>10^5	Total
Upper frequency	5061	1736	62	32	6891
Lower frequency	436	565	276	105	1382