Characteristics of consecutive tsunamis and resulting tsunami behaviors in southern Taiwan induced by the Hengchun earthquake doublet on 26 December 2006
<p>Consecutive <span class="inline-formula"><i>M</i><sub>L</sub></span> 7.0 submarine earthquakes occurred offshore of the Hengchun Peninsula, Taiwan, on 26 December 2006. A small tsunami was generated and recorded at tide gauge stations. This impo...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-02-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | https://nhess.copernicus.org/articles/23/447/2023/nhess-23-447-2023.pdf |
| _version_ | 1811173069395329024 |
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| author | A.-C. Cheng A.-C. Cheng A. Suppasri A. Suppasri K. Pakoksung F. Imamura F. Imamura |
| author_facet | A.-C. Cheng A.-C. Cheng A. Suppasri A. Suppasri K. Pakoksung F. Imamura F. Imamura |
| author_sort | A.-C. Cheng |
| collection | DOAJ |
| description | <p>Consecutive <span class="inline-formula"><i>M</i><sub>L</sub></span> 7.0 submarine earthquakes occurred offshore of the Hengchun Peninsula, Taiwan, on 26 December 2006. A small tsunami was generated and recorded at tide gauge stations. This important event attracted public interest, as it was generated by an earthquake doublet and produced a tsunami risk for Taiwan. This study analyzed tide gauge tsunami waveforms and numerical simulations to understand the source characteristics
and resulting behaviors of tsunamis. The maximum wave heights at the three
nearest stations were 0.08 m (Kaohsiung), 0.12 m (Dongkung), and 0.3 m
(Houbihu), and only Houbihu recorded the first wave crest as the largest.
The tsunami duration was 3.9 h at Dongkung and over 6 h at Kaohsiung and
Houbihu. Spectral analyses detected dominant periodic components of spectral peaks on the tsunami waveforms. The period band from 13.6–23.1 min was identified as the tsunami source spectrum, and the approximate fault area for the consecutive tsunamis was estimated to be 800 km<span class="inline-formula"><sup>2</sup></span>, with central fault depths of 20 km (first earthquake, <span class="inline-formula"><i>M</i><sub>w</sub></span> 7.0) and 33 km (second earthquake, <span class="inline-formula"><i>M</i><sub>w</sub></span> 6.9). The focal mechanisms of the first earthquake, with
a strike of 319<span class="inline-formula"><sup>∘</sup></span>, dip of 69<span class="inline-formula"><sup>∘</sup></span>, and rake of
<span class="inline-formula">−</span>102<span class="inline-formula"><sup>∘</sup></span>, and the second earthquake, with a strike of 151<span class="inline-formula"><sup>∘</sup></span>, dip of 48<span class="inline-formula"><sup>∘</sup></span>, and rake of 0<span class="inline-formula"><sup>∘</sup></span>, could successfully
reproduce the observed tsunami waveforms. Numerical simulations suggested
that the tsunami waves were coastally trapped on the south coast of Taiwan
during the tsunami's passage. The trapped waves propagated along the coast
as edge waves, which repeatedly reflected and refracted among the shelves,
interfered with incoming incident wave, and resonated with the fundamental
modes of the shelves, amplifying and continuing the tsunami wave
oscillation. These results elucidated the generation and consequential
behaviors of the 2006 tsunami in southern Taiwan, contributing essential
information for tsunami warning and coastal emergency response in Taiwan to
reduce disaster risk.</p> |
| first_indexed | 2024-04-10T17:41:49Z |
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| id | doaj.art-2479b39033c64f68baa3fa882bca897c |
| institution | Directory Open Access Journal |
| issn | 1561-8633 1684-9981 |
| language | English |
| last_indexed | 2024-04-10T17:41:49Z |
| publishDate | 2023-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Natural Hazards and Earth System Sciences |
| spelling | doaj.art-2479b39033c64f68baa3fa882bca897c2023-02-03T11:15:21ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812023-02-012344747910.5194/nhess-23-447-2023Characteristics of consecutive tsunamis and resulting tsunami behaviors in southern Taiwan induced by the Hengchun earthquake doublet on 26 December 2006A.-C. Cheng0A.-C. Cheng1A. Suppasri2A. Suppasri3K. Pakoksung4F. Imamura5F. Imamura6Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aoba, Aramaki-Aza, Aoba, Sendai 980-0845, JapanWISE Program for sustainability in the Dynamic Earth, Tohoku University, 6-3 Aoba, Aramaki Aza, Aoba, Sendai 980-8578, JapanWISE Program for sustainability in the Dynamic Earth, Tohoku University, 6-3 Aoba, Aramaki Aza, Aoba, Sendai 980-8578, JapanInternational Research Institute of Disaster Science, Tohoku University, 468-1 Aoba, Aramaki-Aza, Aoba, Sendai 980-0845, JapanInternational Research Institute of Disaster Science, Tohoku University, 468-1 Aoba, Aramaki-Aza, Aoba, Sendai 980-0845, JapanWISE Program for sustainability in the Dynamic Earth, Tohoku University, 6-3 Aoba, Aramaki Aza, Aoba, Sendai 980-8578, JapanInternational Research Institute of Disaster Science, Tohoku University, 468-1 Aoba, Aramaki-Aza, Aoba, Sendai 980-0845, Japan<p>Consecutive <span class="inline-formula"><i>M</i><sub>L</sub></span> 7.0 submarine earthquakes occurred offshore of the Hengchun Peninsula, Taiwan, on 26 December 2006. A small tsunami was generated and recorded at tide gauge stations. This important event attracted public interest, as it was generated by an earthquake doublet and produced a tsunami risk for Taiwan. This study analyzed tide gauge tsunami waveforms and numerical simulations to understand the source characteristics and resulting behaviors of tsunamis. The maximum wave heights at the three nearest stations were 0.08 m (Kaohsiung), 0.12 m (Dongkung), and 0.3 m (Houbihu), and only Houbihu recorded the first wave crest as the largest. The tsunami duration was 3.9 h at Dongkung and over 6 h at Kaohsiung and Houbihu. Spectral analyses detected dominant periodic components of spectral peaks on the tsunami waveforms. The period band from 13.6–23.1 min was identified as the tsunami source spectrum, and the approximate fault area for the consecutive tsunamis was estimated to be 800 km<span class="inline-formula"><sup>2</sup></span>, with central fault depths of 20 km (first earthquake, <span class="inline-formula"><i>M</i><sub>w</sub></span> 7.0) and 33 km (second earthquake, <span class="inline-formula"><i>M</i><sub>w</sub></span> 6.9). The focal mechanisms of the first earthquake, with a strike of 319<span class="inline-formula"><sup>∘</sup></span>, dip of 69<span class="inline-formula"><sup>∘</sup></span>, and rake of <span class="inline-formula">−</span>102<span class="inline-formula"><sup>∘</sup></span>, and the second earthquake, with a strike of 151<span class="inline-formula"><sup>∘</sup></span>, dip of 48<span class="inline-formula"><sup>∘</sup></span>, and rake of 0<span class="inline-formula"><sup>∘</sup></span>, could successfully reproduce the observed tsunami waveforms. Numerical simulations suggested that the tsunami waves were coastally trapped on the south coast of Taiwan during the tsunami's passage. The trapped waves propagated along the coast as edge waves, which repeatedly reflected and refracted among the shelves, interfered with incoming incident wave, and resonated with the fundamental modes of the shelves, amplifying and continuing the tsunami wave oscillation. These results elucidated the generation and consequential behaviors of the 2006 tsunami in southern Taiwan, contributing essential information for tsunami warning and coastal emergency response in Taiwan to reduce disaster risk.</p>https://nhess.copernicus.org/articles/23/447/2023/nhess-23-447-2023.pdf |
| spellingShingle | A.-C. Cheng A.-C. Cheng A. Suppasri A. Suppasri K. Pakoksung F. Imamura F. Imamura Characteristics of consecutive tsunamis and resulting tsunami behaviors in southern Taiwan induced by the Hengchun earthquake doublet on 26 December 2006 Natural Hazards and Earth System Sciences |
| title | Characteristics of consecutive tsunamis and resulting tsunami behaviors in southern Taiwan induced by the Hengchun earthquake doublet on 26 December 2006 |
| title_full | Characteristics of consecutive tsunamis and resulting tsunami behaviors in southern Taiwan induced by the Hengchun earthquake doublet on 26 December 2006 |
| title_fullStr | Characteristics of consecutive tsunamis and resulting tsunami behaviors in southern Taiwan induced by the Hengchun earthquake doublet on 26 December 2006 |
| title_full_unstemmed | Characteristics of consecutive tsunamis and resulting tsunami behaviors in southern Taiwan induced by the Hengchun earthquake doublet on 26 December 2006 |
| title_short | Characteristics of consecutive tsunamis and resulting tsunami behaviors in southern Taiwan induced by the Hengchun earthquake doublet on 26 December 2006 |
| title_sort | characteristics of consecutive tsunamis and resulting tsunami behaviors in southern taiwan induced by the hengchun earthquake doublet on 26 december 2006 |
| url | https://nhess.copernicus.org/articles/23/447/2023/nhess-23-447-2023.pdf |
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