Scattering and Intrinsic Attenuation of Short-Period S Waves in the Gyeongsang Basin, South Korea, Revealed from S-Wave Seismogram Envelopes Based on the Radiative Transfer Theory

Abstract

Abstract Examining seismic envelopes for local earthquakes that occurred in the Gyeongsang Basin, South Korea, we estimated coda Q values in the crust and measured the total scattering coefficients for frequency bands 1–2, 2–4, 4–8, and 8–16 Hz using the Monte Carlo simulation method based on radiative transfer theory. In the seismic envelope synthesis, we assumed acoustic multiple isotropic scattering and adopted a depth-dependent S -wave velocity model that is slightly modified from a receiver function result in the middle of the study region. The estimated total scattering coefficients range from 3.8×10 -3 to at 1–16 Hz, which agrees well with the average values in the crust. These values are corresponding to less than 0.5 of seismic albedo. This result represents that intrinsic absorption is a dominant contributor to the attenuation process for all frequency bands in the Gyeongsang Basin.