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Seismic Wavefields in the Deep Seafloor Area from a Submarine Landslide Source
https://nied-repo.bosai.go.jp/records/4136
https://nied-repo.bosai.go.jp/records/4136af70f912-c348-4878-bde2-b3bafd91dd92
| 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 | Seismic Wavefields in the Deep Seafloor Area from a Submarine Landslide Source | |||||||||||||
| 言語 | ||||||||||||||
| 言語 | eng | |||||||||||||
| 著者 |
Takeshi Nakamura
× Takeshi Nakamura
× Hiroshi Takenaka
× Taro Okamoto
× Yoshiyuki Kaneda
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| 抄録 | ||||||||||||||
| 内容記述タイプ | Other | |||||||||||||
| 内容記述 | We use the finite difference method to simulate seismic wavefields at broadband land and seafloor stations for a given terrestrial landslide source, where the seafloor stations are located at water depths of 1,900-4,300 m. Our simulation results for the landslide source explain observations well at the seafloor stations for a frequency range of 0.05-0.1 Hz. Assuming the epicenter to be located in the vicinity of a large submarine slump, we also model wavefields at the stations for a submarine landslide source. We detect propagation of the Airy phase with an apparent velocity of 0.7 km/s in association with the seawater layer and an accretionary prism for the vertical component of waveforms at the seafloor stations. This later phase is not detected when the structural model does not consider seawater. For the model incorporating the seawater, the amplitude of the vertical component at seafloor stations can be up to four times that for the model that excludes seawater; we attribute this to the effects of the seawater layer on the wavefields. We also find that the amplification of the waveform depends not only on the presence of the seawater layer but also on the thickness of the accretionary prism, indicating low amplitudes at the land stations and at seafloor stations located near the trough but high amplitudes at other stations, particularly those located above the thick prism off the trough. Ignoring these characteristic structures in the oceanic area and simply calculating the wavefields using the same structural model used for land areas would result in erroneous estimates of the size of the submarine landslide and the mechanisms underlying its generation. Our results highlight the importance of adopting a structural model that incorporates the 3D accretionary prism and seawater layer into the simulation in order to precisely evaluate seismic wavefields in seafloor areas. | |||||||||||||
| 言語 | en | |||||||||||||
| 書誌情報 |
en : PURE AND APPLIED GEOPHYSICS 巻 171, 号 7, p. 1153-1167 |
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| 言語 | en | |||||||||||||
| 出版者 | SPRINGER BASEL AG | |||||||||||||
| ISSN | ||||||||||||||
| 収録物識別子タイプ | EISSN | |||||||||||||
| 収録物識別子 | 1420-9136 | |||||||||||||
| DOI | ||||||||||||||
| 関連識別子 | 10.1007/s00024-013-0717-3 | |||||||||||||
