Microseismic multi-parameter characteristics of rockburst hazard induced by hard roof fall and high stress concentration

• Before rockburst, the sudden rise of MS energy and the lower level of event count.
• When rockburst, peak value of fault total area, the lower b   value, and |Z||Z|>2.
• When rockburst, the largest energy ratio in the dominant low-frequency band.
• Before rockburst, abnormal cluster of sources and high-energy events congregation.
• Prior to rockburst, the sudden drop of EME amplitude indicating macro-fracture.