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Interference of long-period seismic wavefield observed by the dense Hi-net array in Japan
https://nied-repo.bosai.go.jp/records/4552
https://nied-repo.bosai.go.jp/records/4552290af162-fac6-4155-95b4-6af0f23d242a
| Item type | researchmap(1) | |||||||||||||
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| 公開日 | 2023-03-30 | |||||||||||||
| タイトル | ||||||||||||||
| 言語 | en | |||||||||||||
| タイトル | Interference of long-period seismic wavefield observed by the dense Hi-net array in Japan | |||||||||||||
| 言語 | ||||||||||||||
| 言語 | eng | |||||||||||||
| 著者 |
Takuto Maeda
× Takuto Maeda
× Kazushige Obara
× Takashi Furumura
× Tatsuhiko Saito
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| 抄録 | ||||||||||||||
| 内容記述タイプ | Other | |||||||||||||
| 内容記述 | In order to recover small signals of long-period ground motions recorded by a short-period seismometer, we designed a time domain recursive filter that simulates seismic waves recorded with broadband seismometers. We applied the time domain filter to seismograms recorded by the dense Hi-net array, which consists of 800 stations at intervals of approximately 20 km. The effectiveness of the time domain filter is demonstrated through the comparison of broadband waveforms obtained by the filter and STS-2 true broadband seismograms from the F-net at the same site. Good agreement is observed between filtered and true broadband waveforms with high correlation coefficients for periods of up to 100 s for waveforms from the 2007 Sumatra earthquake (M7.9), which occurred approximately 5000-5800 km away from Japan. The applicability of the time domain filter to the recovery of long-period signals from the record of a short-period seismometer depends on the signal-to-noise ratio. As a result, a limited bandwidth of broadband signal is recovered for smaller earthquake. From the spatiotemporal variation of the long-period (T = 20-100 s) wavefield obtained by the time domain filter, we newly found an anomalous phase pattern of splitting of polarity along the wavefront, particularly for the relatively short period band of from 20-50 s. Array analysis of the dense broadband waveforms revealed multipathing of the Rayleigh waves, which propagated toward central Japan from two directions with slightly different slowness vectors. The interference of two Rayleigh waves caused such splitting of wavefield. | |||||||||||||
| 言語 | en | |||||||||||||
| 書誌情報 |
en : JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 巻 116, 発行日 2011-10 |
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| 出版者 | ||||||||||||||
| 言語 | en | |||||||||||||
| 出版者 | AMER GEOPHYSICAL UNION | |||||||||||||
| ISSN | ||||||||||||||
| 収録物識別子タイプ | EISSN | |||||||||||||
| 収録物識別子 | 2169-9356 | |||||||||||||
| DOI | ||||||||||||||
| 関連識別子 | 10.1029/2011JB008464 | |||||||||||||
