A parameter quantifying radiation damping of bay oscillations excited by incident tsunamis

Takahiro Endo, Daisuke Inazu, Takuji Waseda, Toshiyuki Hibiya

研究成果: ジャーナルへの寄稿記事

抄録

The transient response of a bay with a narrow mouth to incident tsunamis is interpreted as the convolution of the input signal with the impulse response obtained by an inverse Fourier transform of the response curve of the oscillatory system with one degree of freedom. The rate of radiation damping associated with energy escaping seaward through the bay mouth is expressed in terms of the quality factor Q, which determines the decaying envelope of the impulse response. The value of Q of the resonant peak is approximated by the ratio of the resonant frequency ω0 to the bandwidth between frequencies at which the power spectral density of sea level within the bay drops to half of the peak value. Since the shape of the frequency power spectrum during the tsunami event is almost similar to that in the normal state in the neighborhood of ω0, Q can be estimated from sea level datasets in the normal state. Although the amplitude and phase of the impulse response need to be adjusted using the first crest or trough of the observed leading wave, this approach proves to work well in examining the transient responses of Miyako Bay and Kushimoto Bay on the Japanese Pacific coast to incident tsunamis.

元の言語英語
ページ(範囲)10-19
ページ数10
ジャーナルContinental Shelf Research
157
DOI
出版物ステータス出版済み - 4 1 2018
外部発表Yes

Fingerprint

tsunamis
tsunami
damping
oscillation
sea level
mouth
tsunami event
Q factor
coasts
energy
Fourier transform
trough
radiation
parameter
coast

All Science Journal Classification (ASJC) codes

  • Oceanography
  • Aquatic Science
  • Geology

これを引用

A parameter quantifying radiation damping of bay oscillations excited by incident tsunamis. / Endo, Takahiro; Inazu, Daisuke; Waseda, Takuji; Hibiya, Toshiyuki.

:: Continental Shelf Research, 巻 157, 01.04.2018, p. 10-19.

研究成果: ジャーナルへの寄稿記事

Endo, Takahiro ; Inazu, Daisuke ; Waseda, Takuji ; Hibiya, Toshiyuki. / A parameter quantifying radiation damping of bay oscillations excited by incident tsunamis. :: Continental Shelf Research. 2018 ; 巻 157. pp. 10-19.
@article{503f2d2df8cb44e7ac2f7b621541a866,
title = "A parameter quantifying radiation damping of bay oscillations excited by incident tsunamis",
abstract = "The transient response of a bay with a narrow mouth to incident tsunamis is interpreted as the convolution of the input signal with the impulse response obtained by an inverse Fourier transform of the response curve of the oscillatory system with one degree of freedom. The rate of radiation damping associated with energy escaping seaward through the bay mouth is expressed in terms of the quality factor Q, which determines the decaying envelope of the impulse response. The value of Q of the resonant peak is approximated by the ratio of the resonant frequency ω0 to the bandwidth between frequencies at which the power spectral density of sea level within the bay drops to half of the peak value. Since the shape of the frequency power spectrum during the tsunami event is almost similar to that in the normal state in the neighborhood of ω0, Q can be estimated from sea level datasets in the normal state. Although the amplitude and phase of the impulse response need to be adjusted using the first crest or trough of the observed leading wave, this approach proves to work well in examining the transient responses of Miyako Bay and Kushimoto Bay on the Japanese Pacific coast to incident tsunamis.",
author = "Takahiro Endo and Daisuke Inazu and Takuji Waseda and Toshiyuki Hibiya",
year = "2018",
month = "4",
day = "1",
doi = "10.1016/j.csr.2018.02.007",
language = "English",
volume = "157",
pages = "10--19",
journal = "Continental Shelf Research",
issn = "0278-4343",
publisher = "Elsevier Limited",

}

TY - JOUR

T1 - A parameter quantifying radiation damping of bay oscillations excited by incident tsunamis

AU - Endo, Takahiro

AU - Inazu, Daisuke

AU - Waseda, Takuji

AU - Hibiya, Toshiyuki

PY - 2018/4/1

Y1 - 2018/4/1

N2 - The transient response of a bay with a narrow mouth to incident tsunamis is interpreted as the convolution of the input signal with the impulse response obtained by an inverse Fourier transform of the response curve of the oscillatory system with one degree of freedom. The rate of radiation damping associated with energy escaping seaward through the bay mouth is expressed in terms of the quality factor Q, which determines the decaying envelope of the impulse response. The value of Q of the resonant peak is approximated by the ratio of the resonant frequency ω0 to the bandwidth between frequencies at which the power spectral density of sea level within the bay drops to half of the peak value. Since the shape of the frequency power spectrum during the tsunami event is almost similar to that in the normal state in the neighborhood of ω0, Q can be estimated from sea level datasets in the normal state. Although the amplitude and phase of the impulse response need to be adjusted using the first crest or trough of the observed leading wave, this approach proves to work well in examining the transient responses of Miyako Bay and Kushimoto Bay on the Japanese Pacific coast to incident tsunamis.

AB - The transient response of a bay with a narrow mouth to incident tsunamis is interpreted as the convolution of the input signal with the impulse response obtained by an inverse Fourier transform of the response curve of the oscillatory system with one degree of freedom. The rate of radiation damping associated with energy escaping seaward through the bay mouth is expressed in terms of the quality factor Q, which determines the decaying envelope of the impulse response. The value of Q of the resonant peak is approximated by the ratio of the resonant frequency ω0 to the bandwidth between frequencies at which the power spectral density of sea level within the bay drops to half of the peak value. Since the shape of the frequency power spectrum during the tsunami event is almost similar to that in the normal state in the neighborhood of ω0, Q can be estimated from sea level datasets in the normal state. Although the amplitude and phase of the impulse response need to be adjusted using the first crest or trough of the observed leading wave, this approach proves to work well in examining the transient responses of Miyako Bay and Kushimoto Bay on the Japanese Pacific coast to incident tsunamis.

UR - http://www.scopus.com/inward/record.url?scp=85042620437&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85042620437&partnerID=8YFLogxK

U2 - 10.1016/j.csr.2018.02.007

DO - 10.1016/j.csr.2018.02.007

M3 - Article

AN - SCOPUS:85042620437

VL - 157

SP - 10

EP - 19

JO - Continental Shelf Research

JF - Continental Shelf Research

SN - 0278-4343

ER -