High-resolution separation of earthquake phases using sparsity-promoting polarization filtering method

The extraction of body waves from seismic wave fields has always been a significant interest in the seismological community. Their study provides a picture of the Earth's crust, upper mantle, and critical continuities such as the Moho Transition Zone (e.g., ۴۱۰ km and ۶۶۰ km depth). In addition, it provides information for determining the source mechanism of earthquakes. However, due to their intrinsic weaker amplitude than other seismic waves, they are usually masked by surface waves. Their detection and extraction require advanced analysis and processing tools and methods. This study uses the sparsity-promoting polarization filter method to extract body waves from earthquake waveforms, exploiting their polarization properties in the time-frequency (TF) domain. The computed rectilinearity, directivity, and amplitude attributes calculated from the TF-domain polarization map of earthquake signals are used to discriminate between body and surface waves. Synthetic data examples show the performance of the proposed earthquake phase separation method.

کلیدواژه ها:

body wave ، adaptive time-frequency filtering ، earthquake waveform ، polarization analysis ، sparsity promoting