17:15 〜 19:15
[SSS09-P09] ダブルカップル輻射を考慮した海域地震エンベロープ記録のシミュレーション
キーワード：海域地震、エンベロープ、不均質構造、コーダ波
We simulated S-coda envelopes of interplate earthquakes along a subduction zone by using a Monte Carlo simulation technique based on the radiative transfer theory. In this simulation, we assumed a realistic velocity structure having a subduction plate and an overriding plate with sedimentary layers and a spatially uniform scattering coefficient. Asano (2024) showed that these deterministic heterogeneities such as sedimentary layers more strongly control S-coda envelopes than the spatially uniform stochastic heterogeneity. In this study, we newly introduced the double-couple source radiation and investigated the effect of the source radiation on the simulated envelope seismograms. As simulation results for an interplate event with a 50-km depth, envelope seismograms for a double-couple source and an isotropic source show a clear amplitude difference especially for earlier coda than the mean free time. On the other hand, results of both sources for a near trench interplate event with a 15-km depth are not so different even in the early coda. This suggests that revelation caused by sedimentary layers near the source can mask source radiation pattern.