Assessment of the peak tsunami amplitude associated with a large earthquake occurring along the southernmost Ryukyu subduction zone in the region of Taiwan
<p>The southernmost portion of the Ryukyu Trench near the island of Taiwan potentially generates tsunamigenic earthquakes with magnitudes from 7.5 to 8.7 through shallow rupture. The fault model for this potential region dips 10° northward with a rupture length of 120 km and a wi...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2018-08-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | https://www.nat-hazards-earth-syst-sci.net/18/2081/2018/nhess-18-2081-2018.pdf |
| _version_ | 1818598313380806656 |
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| author | Y.-S. Sun P.-F. Chen C.-C. Chen C.-C. Chen Y.-T. Lee Y.-T. Lee K.-F. Ma K.-F. Ma T.-R. Wu T.-R. Wu T.-R. Wu |
| author_facet | Y.-S. Sun P.-F. Chen C.-C. Chen C.-C. Chen Y.-T. Lee Y.-T. Lee K.-F. Ma K.-F. Ma T.-R. Wu T.-R. Wu T.-R. Wu |
| author_sort | Y.-S. Sun |
| collection | DOAJ |
| description | <p>The southernmost portion of the Ryukyu Trench near the island of
Taiwan potentially generates tsunamigenic earthquakes with magnitudes from
7.5 to 8.7 through shallow rupture. The fault model for this potential region
dips 10° northward with a rupture length of 120 km and a width of
70 km. An earthquake magnitude of <i>M</i><sub>w</sub> 8.15 is estimated by the fault
geometry with an average slip of 8.25 m as a constraint on the earthquake
scenario. Heterogeneous slip distributions over the rupture surface are
generated by a stochastic slip model, which represents the decaying slip spectrum
according to <i>k</i><sup>−2</sup> in the wave number domain. These synthetic slip
distributions are consistent with the abovementioned identical seismic
conditions. The results from tsunami simulations illustrate that the
propagation of tsunami waves and the peak wave heights largely vary in
response to the slip distribution. Changes in the wave phase are possible as
the waves propagate, even under the same seismic conditions. The tsunami
energy path not only follows the bathymetry but also depends on the slip
distribution. The probabilistic distributions of the peak tsunami amplitude
calculated by 100 different slip patterns from 30 recording stations reveal
that the uncertainty decreases with increasing distance from the tsunami
source. The highest wave amplitude for 30 recording points is 7.32 m at
Hualien for 100 different slips. Compared with the stochastic-slip
distributions, the uniform slip distribution will be highly
underestimated, especially in the near field. In general, the uniform slip
assumption only represents the average phenomenon and will consequently
ignore the possibility of tsunami waves. These results indicate that
considering the effects of heterogeneous slip distributions is necessary for
assessing tsunami hazards to provide additional information about tsunami
uncertainties and facilitate a more comprehensive estimation.</p> |
| first_indexed | 2024-12-16T12:01:43Z |
| format | Article |
| id | doaj.art-d02e2caf480a4a048746989fdc02afba |
| institution | Directory Open Access Journal |
| issn | 1561-8633 1684-9981 |
| language | English |
| last_indexed | 2024-12-16T12:01:43Z |
| publishDate | 2018-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Natural Hazards and Earth System Sciences |
| spelling | doaj.art-d02e2caf480a4a048746989fdc02afba2022-12-21T22:32:26ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812018-08-01182081209210.5194/nhess-18-2081-2018Assessment of the peak tsunami amplitude associated with a large earthquake occurring along the southernmost Ryukyu subduction zone in the region of TaiwanY.-S. Sun0P.-F. Chen1C.-C. Chen2C.-C. Chen3Y.-T. Lee4Y.-T. Lee5K.-F. Ma6K.-F. Ma7T.-R. Wu8T.-R. Wu9T.-R. Wu10Department of Earth Sciences, National Central University, Taoyuan City 32001, Taiwan, R.O.C.Department of Earth Sciences, National Central University, Taoyuan City 32001, Taiwan, R.O.C.Department of Earth Sciences, National Central University, Taoyuan City 32001, Taiwan, R.O.C.Earthquake-Disaster & Risk Evaluation and Management Center, National Central University, Taoyuan City 32001, Taiwan, R.O.C.Department of Earth Sciences, National Central University, Taoyuan City 32001, Taiwan, R.O.C.Earthquake-Disaster & Risk Evaluation and Management Center, National Central University, Taoyuan City 32001, Taiwan, R.O.C.Department of Earth Sciences, National Central University, Taoyuan City 32001, Taiwan, R.O.C.Earthquake-Disaster & Risk Evaluation and Management Center, National Central University, Taoyuan City 32001, Taiwan, R.O.C.Earthquake-Disaster & Risk Evaluation and Management Center, National Central University, Taoyuan City 32001, Taiwan, R.O.C.Graduate Institute of Hydrological and Oceanic Sciences, National Central University, Taoyuan City 32001, Taiwan, R.O.C.Center of Excellence for Ocean Engineering, National Taiwan Ocean University, Keelung, Taiwan<p>The southernmost portion of the Ryukyu Trench near the island of Taiwan potentially generates tsunamigenic earthquakes with magnitudes from 7.5 to 8.7 through shallow rupture. The fault model for this potential region dips 10° northward with a rupture length of 120 km and a width of 70 km. An earthquake magnitude of <i>M</i><sub>w</sub> 8.15 is estimated by the fault geometry with an average slip of 8.25 m as a constraint on the earthquake scenario. Heterogeneous slip distributions over the rupture surface are generated by a stochastic slip model, which represents the decaying slip spectrum according to <i>k</i><sup>−2</sup> in the wave number domain. These synthetic slip distributions are consistent with the abovementioned identical seismic conditions. The results from tsunami simulations illustrate that the propagation of tsunami waves and the peak wave heights largely vary in response to the slip distribution. Changes in the wave phase are possible as the waves propagate, even under the same seismic conditions. The tsunami energy path not only follows the bathymetry but also depends on the slip distribution. The probabilistic distributions of the peak tsunami amplitude calculated by 100 different slip patterns from 30 recording stations reveal that the uncertainty decreases with increasing distance from the tsunami source. The highest wave amplitude for 30 recording points is 7.32 m at Hualien for 100 different slips. Compared with the stochastic-slip distributions, the uniform slip distribution will be highly underestimated, especially in the near field. In general, the uniform slip assumption only represents the average phenomenon and will consequently ignore the possibility of tsunami waves. These results indicate that considering the effects of heterogeneous slip distributions is necessary for assessing tsunami hazards to provide additional information about tsunami uncertainties and facilitate a more comprehensive estimation.</p>https://www.nat-hazards-earth-syst-sci.net/18/2081/2018/nhess-18-2081-2018.pdf |
| spellingShingle | Y.-S. Sun P.-F. Chen C.-C. Chen C.-C. Chen Y.-T. Lee Y.-T. Lee K.-F. Ma K.-F. Ma T.-R. Wu T.-R. Wu T.-R. Wu Assessment of the peak tsunami amplitude associated with a large earthquake occurring along the southernmost Ryukyu subduction zone in the region of Taiwan Natural Hazards and Earth System Sciences |
| title | Assessment of the peak tsunami amplitude associated with a large earthquake occurring along the southernmost Ryukyu subduction zone in the region of Taiwan |
| title_full | Assessment of the peak tsunami amplitude associated with a large earthquake occurring along the southernmost Ryukyu subduction zone in the region of Taiwan |
| title_fullStr | Assessment of the peak tsunami amplitude associated with a large earthquake occurring along the southernmost Ryukyu subduction zone in the region of Taiwan |
| title_full_unstemmed | Assessment of the peak tsunami amplitude associated with a large earthquake occurring along the southernmost Ryukyu subduction zone in the region of Taiwan |
| title_short | Assessment of the peak tsunami amplitude associated with a large earthquake occurring along the southernmost Ryukyu subduction zone in the region of Taiwan |
| title_sort | assessment of the peak tsunami amplitude associated with a large earthquake occurring along the southernmost ryukyu subduction zone in the region of taiwan |
| url | https://www.nat-hazards-earth-syst-sci.net/18/2081/2018/nhess-18-2081-2018.pdf |
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