Simulation of the time feature of infrasonic signals during the rupture process of an earthquake

Abnormal infrasonic signals can be observed within a few days before a strong earthquake. Infrasound conveys information about the size and growth of the crack. To date, however, most studies have used infrasonic intensity as the basic parameter for earthquake monitoring. Based on observations, the current study simulated the time parameter of the acoustic elastic waves during deformation and catastrophic events caused by the evolution and accumulation of geological body fractures before an earthquake. The quantitative relations between the length of the pulse front edge and the scale and growth velocity of the crack indicated that the length of the pulse back edge was associated with the size of the deloading zone. The existence of the undeformed acoustic pulse when the crack occurred indicated the consistency between the length of the front edge and the growth time of the crack. The characteristics of acoustic abnormalities might be a direct reflection of fracture severity, whose variations can characterize the occurrence of the main fracture. As the precursor of an earthquake, acoustic abnormalities can be considered as key data in simulations of earthquake prediction.