资源环境科技发展态势分析平台

Crustal attenuation structures obtained at high frequencies (>1 Hz) are important for seismic risk assessment and geodynamics studies in stable continents. However, it is difficult to infer attenuation in low seismicity regions using body and surface waves. In this study, we explore the potential of using seismic T phases to constrain the crustal attenuation. We analyzed the characteristics of T waves recorded on the seismic array deployed in southern Africa. The converted station-side T-P and T-S phases were identified by analyzing the waveform, travel time, polarization and frequency-wavenumber features. The distinct differences in polarization and slowness are used to quantify contributions from T-P and T-S conversions. The inverted frequency-dependent Qp and Qs (attenuation factor of local P and S waves, respectively) in the southern Africa are found to be and , respectively. Our method could be extended to infer crustal attenuation features near the coasts of other continents.