WEKO3
アイテム
Improving the constraint on the Mw 7.1 2016 off-Fukushima shallow normal-faulting earthquake with the high azimuthal coverage tsunami data from the S-net wide and dense network: Implication for the stress regime in the Tohoku overriding plate
https://nied-repo.bosai.go.jp/records/2886
https://nied-repo.bosai.go.jp/records/28864008fe71-79dc-4b86-93d4-790d3336d096
| Item type | researchmap(1) | |||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 公開日 | 2023-03-30 | |||||||||||||||||||||||||||||||||
| タイトル | ||||||||||||||||||||||||||||||||||
| 言語 | ja | |||||||||||||||||||||||||||||||||
| タイトル | Improving the constraint on the Mw 7.1 2016 off-Fukushima shallow normal-faulting earthquake with the high azimuthal coverage tsunami data from the S-net wide and dense network: Implication for the stress regime in the Tohoku overriding plate | |||||||||||||||||||||||||||||||||
| タイトル | ||||||||||||||||||||||||||||||||||
| 言語 | en | |||||||||||||||||||||||||||||||||
| タイトル | Improving the constraint on the Mw 7.1 2016 off-Fukushima shallow normal-faulting earthquake with the high azimuthal coverage tsunami data from the S-net wide and dense network: Implication for the stress regime in the Tohoku overriding plate | |||||||||||||||||||||||||||||||||
| 言語 | ||||||||||||||||||||||||||||||||||
| 言語 | eng | |||||||||||||||||||||||||||||||||
| 著者 |
Tatsuya Kubota
× Tatsuya Kubota
× Hisahiko Kubo
× Keisuke Yoshida
× Naotaka Y. Chikasada
× Wataru Suzuki
× Takeshi Nakamura
× Hiroaki Tsushima
|
|||||||||||||||||||||||||||||||||
| 抄録 | ||||||||||||||||||||||||||||||||||
| 内容記述タイプ | Other | |||||||||||||||||||||||||||||||||
| 内容記述 | Tsunamis with amplitudes of up to 40 cm, related to the Mw 7.1 normal-faulting earthquake off Fukushima, Japan, on November 21, 2016, were clearly recorded by a new offshore wide and dense ocean-bottom pressure gauge network, S-net, with high azimuthal coverage located closer to the focal area. We processed the S-net data and found some stations included the tsunami-irrelevant drift and step signals. We analyzed the S-net data to infer the tsunami source distribution. A subsidence region with a narrow spatial extent (?40 km) and a large peak (?200 cm) was obtained. The other near-coastal waveforms not used for the inversion analysis were also reproduced very well. Our fault model suggests the maximum stress drop across the fault plane of > ?10 MPa and the average of 4.2 MPa, whereas the shear stress increase along the fault caused by the 2011 Tohoku earthquake was only ?2 MPa. Past studies have suggested that horizontal compressional stress around this region switched to horizontal extensional stress after the Tohoku earthquake due to its stress perturbation. The present result, however, suggests that the horizontal extensional stress was locally predominant at the shallowest surface around the focal area even before 2011. The present study demonstrates that the S-net high-azimuthal-coverage pressure data provides a significant constraint on the fault modeling, which enables us to discuss the stress regime within the overriding plate at the offshore. Our analysis provides an implication for crustal stress states, which is important for understanding generation mechanisms of intraplate earthquakes. | |||||||||||||||||||||||||||||||||
| 言語 | ja | |||||||||||||||||||||||||||||||||
| 抄録 | ||||||||||||||||||||||||||||||||||
| 内容記述タイプ | Other | |||||||||||||||||||||||||||||||||
| 内容記述 | Tsunamis with amplitudes of up to 40 cm, related to the Mw 7.1 normal-faulting earthquake off Fukushima, Japan, on November 21, 2016, were clearly recorded by a new offshore wide and dense ocean-bottom pressure gauge network, S-net, with high azimuthal coverage located closer to the focal area. We processed the S-net data and found some stations included the tsunami-irrelevant drift and step signals. We analyzed the S-net data to infer the tsunami source distribution. A subsidence region with a narrow spatial extent (?40 km) and a large peak (?200 cm) was obtained. The other near-coastal waveforms not used for the inversion analysis were also reproduced very well. Our fault model suggests the maximum stress drop across the fault plane of > ?10 MPa and the average of 4.2 MPa, whereas the shear stress increase along the fault caused by the 2011 Tohoku earthquake was only ?2 MPa. Past studies have suggested that horizontal compressional stress around this region switched to horizontal extensional stress after the Tohoku earthquake due to its stress perturbation. The present result, however, suggests that the horizontal extensional stress was locally predominant at the shallowest surface around the focal area even before 2011. The present study demonstrates that the S-net high-azimuthal-coverage pressure data provides a significant constraint on the fault modeling, which enables us to discuss the stress regime within the overriding plate at the offshore. Our analysis provides an implication for crustal stress states, which is important for understanding generation mechanisms of intraplate earthquakes. | |||||||||||||||||||||||||||||||||
| 言語 | en | |||||||||||||||||||||||||||||||||
| 書誌情報 |
ja : Journal of Geophysical Research: Solid Earth en : Journal of Geophysical Research: Solid Earth 巻 126, 号 10, p. e2021JB022223, 発行日 2021-10-13 |
|||||||||||||||||||||||||||||||||
| 出版者 | ||||||||||||||||||||||||||||||||||
| 言語 | ja | |||||||||||||||||||||||||||||||||
| 出版者 | American Geophysical Union | |||||||||||||||||||||||||||||||||
| 出版者 | ||||||||||||||||||||||||||||||||||
| 言語 | en | |||||||||||||||||||||||||||||||||
| 出版者 | American 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 | 10.1029/2021JB022223 | |||||||||||||||||||||||||||||||||
