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Determination of the source parameters of the 2011 Tohoku-Oki earthquake from three-component pre-P gravity signals recorded by dense arrays in Japan
https://nied-repo.bosai.go.jp/records/3118
https://nied-repo.bosai.go.jp/records/31189d445ee2-b4cf-443e-a216-bf7e2847f033
| 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 | Determination of the source parameters of the 2011 Tohoku-Oki earthquake from three-component pre-P gravity signals recorded by dense arrays in Japan | |||||||||||||||||
| 言語 | ||||||||||||||||||
| 言語 | eng | |||||||||||||||||
| 著者 |
Masaya Kimura
× Masaya Kimura
× Nobuki Kame
× Shingo Watada
× Akito Araya
× Takashi Kunugi
× Rongjiang Wang
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| 抄録 | ||||||||||||||||||
| 内容記述タイプ | Other | |||||||||||||||||
| 内容記述 | Abstract Dynamic earthquake rupture causes mass redistribution around the fault, and the emitted propagating seismic waves are accompanied by bulk density perturbations. Both processes cause transient gravity changes prior to the arrival of P-waves. Such pre-P gravity signals have been detected in previous studies of several large earthquakes. However, the detections were limited to the vertical component of the signal owing to the high noise level in the horizontal records. In this study, we analyzed dense tiltmeter array data in Japan to search for the horizontal components of the signal from the 2011 Mw 9.1 Tohoku-Oki earthquake. Based on the synthetic waveforms computed for a realistic Earth model, we stacked the horizontal records and identified a signal that evidently exceeded the noise level. We further performed a waveform inversion analysis to estimate the source parameters. The horizontal tiltmeter data, combined with the vertical component of the broadband seismometer array data, yielded a constraint on the dip angle and magnitude of the earthquake in the ranges of 11.5°?15.3° and 8.75°?8.92°, respectively. Our results indicate that the analysis of the three components of the pre-P gravity signal avoids the intrinsic trade-off problem between the dip angle and seismic moment in determining the source mechanism of shallow earthquakes. Pre-P gravity signals open a new observation window for earthquake source studies. Graphical Abstract |
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| 言語 | en | |||||||||||||||||
| 書誌情報 |
en : Earth, Planets and Space 巻 73, 号 1, 発行日 2021-12 |
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| 言語 | en | |||||||||||||||||
| 出版者 | Springer Science and Business Media LLC | |||||||||||||||||
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| 収録物識別子タイプ | EISSN | |||||||||||||||||
| 収録物識別子 | 1880-5981 | |||||||||||||||||
| DOI | ||||||||||||||||||
| 関連識別子 | 10.1186/s40623-021-01553-7 | |||||||||||||||||
