第91回ジオダイナミクスセミナー
　　　Geodynamics　Seminar

　　　　　　　　　
　「高分解能地震波トモグラフィー及び南カリフォルニア
　　への応用」
　　 "High resolution seismic tomography approached in
　　　Southern California "　
　　　　　　　
　　　　　　　講師：東藤幸子（愛媛大学修士１年）　
　
　　　　　　　　
　　　　　　　　主催　：　愛媛大学地球深部ダイナミクス研究センター
　　　　　日時　：　２００４年２月２０日（金）午後17時〜
　　　　　場所　：　愛媛大学理学部講義棟　２０１教室　　　

要　旨
　In this study, we have tried to pick up multiple reflection waves in the crust from local earthquakes and add the reflective wave data to conduct tomographic inversions. For the later phase identification, we compare observed seismograms with the synthetic ones. We applied this approach to the 1992 Landers earthquake (M 7.3) region in Southern California. In this region, waveform modeling studies have been carried out by Helmberger et al. (2001) for the Landers aftershocks. From the seismograms of 189 Landers aftershocks recorded by two seismic stations (PFO,GSC), we picked up 222 first S arrivals, 216 SmS and 120 sSmS arrivals and used them in tomographic inversions. Our results show that the joint use of the three types of waves significantly improve the ray path coverage in the crust, which results in a spatial resolution of about 30 km in horizontal direction and 5-13 km in depth.




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