Microseismic forward modeling based on different focal mechanisms used by the seismic moment tensor and elastic wave equation

The source mechanisms of microseismics in hydraulic fracturing present guiding significance to the research on source types, crustal stress analysis and crack prediction. Numerical simulations based on various source mechanisms can be used to investigate the stress characteristics and response characteristics of different source types. In this paper, a method based on the seismic moment tensor (SMT) and elastic wave equation (EWE) was presented for forward modeling. Additionally, we have given the expressions of nine couples of force which can be combined into different kinds of source types. The calculations of wave fields and records with three basic types of sources showed the features in homogeneous isotropic and anisotropic media by the finite-difference (FD) method. Lastly, analysis of the relationship between the polarizing angle and incident angle provided us with some evidence to distinguish the type of media in single media. The work offers methods of instruction for identification and interpretation in microseismic monitoring.