Radiation patterns: Possibility for monitoring seismic sources

摘要

In this paper, we emphasized the role of the medium parameters and frequency on the computed radiation patterns of vertical and rotational loads over disk of small radius. Similar to a homogeneous Earth, the radiation patterns are decoupled into rotational (SH) and qP-qSV propagation caused by rotational and vertical loads. On the other hand, there is a big difference in computed radiation patterns compared to a homogeneous and isotropic Earth propagation. In the case of fine horizontal stratification, the medium behaves as a TI (anisotropic) material showing coupling between quasi-compressional and quasi-shear waves. Opposed to this case, when the layers are "thick," radiation is characterized by strong dispersion. We conclude that computed radiation patterns can be important for accurate monitoring of complex seismic sources if a three-component displacement vector is measured at the surface of the Earth.