Characteristics and Identification of Microseismic Records in Datong Coalfield
To better understand the characteristics of mine earthquakes in Datong Coalfield,we studied the recording data and identification methods of mine earthquakes based on the data of Shanxi Mine Earthquake Monitoring and Research Center,including the non-natural earthquake monitoring carried out by the mine earthquake monitoring research experimental area in northern Shanxi and the Shanxi Earthquake Monitoring Network in Datong Coalfield and surrounding areas for nearly three years(January 2021 to September 2023).The results show that mine earth-quakes occur frequently in Datong Coalfield and surrounding areas and are characterized by micro-seismic or small earthquakes with ML<2.0,with the maximum mine earthquake with ML=2.8.These seismic events exhibit a spatially concentrated distribution,primarily occurring in the vic-inity of coal mining operations,especially in the proximity of deep mines.Compared with natural earthquakes and other non-natural seismic events,the phase of mine earthquakes tends to contain more high-frequency parts,with dominant frequencies generally exceeding 10 Hz.However,they are susceptible to attenuation due to source features and propagation pathways(distance and me-dium).The waveform recording often shows rapid rise and rapid decay,with a short waveform duration.Initial motions are both upward and downward,with a four-quadrant distribution when recorded by multiple seismic stations.