Journal metrics

Journal metrics

  • IF value: 2.281 IF 2.281
  • IF 5-year value: 2.693 IF 5-year 2.693
  • CiteScore value: 2.43 CiteScore 2.43
  • SNIP value: 1.193 SNIP 1.193
  • SJR value: 0.965 SJR 0.965
  • IPP value: 2.31 IPP 2.31
  • h5-index value: 40 h5-index 40
  • Scimago H index value: 73 Scimago H index 73
Volume 18, issue 8 | Copyright
Nat. Hazards Earth Syst. Sci., 18, 2081-2092, 2018
https://doi.org/10.5194/nhess-18-2081-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 01 Aug 2018

Research article | 01 Aug 2018

Assessment of the peak tsunami amplitude associated with a large earthquake occurring along the southernmost Ryukyu subduction zone in the region of Taiwan

Yu-Sheng Sun1, Po-Fei Chen1, Chien-Chih Chen1,2, Ya-Ting Lee1,2, Kuo-Fong Ma1,2, and Tso-Ren Wu2,3,4 Yu-Sheng Sun et al.
  • 1Department of Earth Sciences, National Central University, Taoyuan City 32001, Taiwan, R.O.C.
  • 2Earthquake-Disaster & Risk Evaluation and Management Center, National Central University, Taoyuan City 32001, Taiwan, R.O.C.
  • 3Graduate Institute of Hydrological and Oceanic Sciences, National Central University, Taoyuan City 32001, Taiwan, R.O.C.
  • 4Center of Excellence for Ocean Engineering, National Taiwan Ocean University, Keelung, Taiwan

Abstract. 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 120km and a width of 70km. An earthquake magnitude of Mw8.15 is estimated by the fault geometry with an average slip of 8.25m 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 k−2 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 7.32m 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.

Download & links
Publications Copernicus
Download
Short summary
The maximum possible earthquake magnitude is Mw 8.15 with an average slip of 8.25 m in the southernmost portion of the Ryukyu Trench. One hundred slip distributions of the seismic rupture surface were generated by a stochastic slip model. The simulated results demonstrate that the complexity of the rupture plane has a significant influence on the near field for local tsunamis. The propagation of tsunami waves and the peak wave heights largely vary in response to the slip distribution.
The maximum possible earthquake magnitude is Mw 8.15 with an average slip of 8.25 m in the...
Citation
Share