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Scattering of linear long-wave tsunamis due to randomly fluctuating sea-bottom topography: coda excitation and scattering attenuation
https://nied-repo.bosai.go.jp/records/4758
https://nied-repo.bosai.go.jp/records/47589fff484f-5746-47b5-8e62-1dbd21ff052c
| Item type | researchmap(1) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 公開日 | 2023-03-30 | |||||||||
| タイトル | ||||||||||
| 言語 | en | |||||||||
| タイトル | Scattering of linear long-wave tsunamis due to randomly fluctuating sea-bottom topography: coda excitation and scattering attenuation | |||||||||
| 言語 | ||||||||||
| 言語 | eng | |||||||||
| 著者 |
Tatsuhiko Saito
× Tatsuhiko Saito
× Takashi Furumura
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| 抄録 | ||||||||||
| 内容記述タイプ | Other | |||||||||
| 内容記述 | The scattering coefficient is one of the most fundamental parameters by which to quantify the scattering intensity for waves as a function of scattering angle and wave frequency. This study presents a derivation of the scattering coefficient for linear long-wave tsunami equations in randomly fluctuating sea-bottom topography using the first-order Born approximation. The scattering coefficient is directly related to the power spectrum density function of fluctuations in the bottom topography and shows a strong tsunami-wavelength dependence. The scattering regime is determined by the normalized wavenumber ak, where k is the tsunami wavenumber and a is the correlation distance of the fluctuating sea-bottom topography. The scattering pattern for small wavenumbers, ak << 1, is symmetric in the forward and backward directions, whereas the pattern for large wavenumbers, ak >> 1, shows small-angle scattering around the forward direction. Based on the theoretically derived scattering coefficient, we evaluate the excitation of tsunami coda and leading-wave attenuation as a function of the normalized wavenumber. The coda energy for small wavenumber ak << 1 is proportional to k(3), whereas the energy for large wavenumber ak >> 1 is proportional to k(-p+3) when the power spectral density function of the sea-bottom fluctuation is characterized by a power law with the exponent of -p in large wavenumber. The scattering attenuation represented by the inverse of the quality factor (Sc)Q(-1) is proportional to k(2) for small wavenumber ak << 1, whereas (Sc)Q(-1) is proportional to k(-p+2) for large wavenumber ak >> 1. | |||||||||
| 言語 | en | |||||||||
| 書誌情報 |
en : GEOPHYSICAL JOURNAL INTERNATIONAL 巻 177, 号 3, p. 958-965, 発行日 2009-06 |
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| 出版者 | ||||||||||
| 言語 | en | |||||||||
| 出版者 | WILEY-BLACKWELL PUBLISHING, INC | |||||||||
| ISSN | ||||||||||
| 収録物識別子タイプ | ISSN | |||||||||
| 収録物識別子 | 0956-540X | |||||||||
| DOI | ||||||||||
| 関連識別子 | 10.1111/j.1365-246X.2009.03988.x | |||||||||
