Journal cover Journal topic
Natural Hazards and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Nat. Hazards Earth Syst. Sci., 15, 747-755, 2015
https://doi.org/10.5194/nhess-15-747-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
08 Apr 2015
The role of diffraction effects in extreme run-up inundation at Okushiri Island due to 1993 tsunami
K. O. Kim1, D. C. Kim2, B. H. Choi3, K. T. Jung1, J. H. Yuk4, and E. Pelinovsky5,6 1Marine Radionuclide Research Center, Korea Institute of Ocean Science and Technology, Ansan, 426-744, Korea
2Technology R&D Institute, Hyein E&C Co. Ltd., Seoul, 157-861, Korea
3Department of Civil and Environmental Engineering, Sungkyunkwan University, Chunchun-dong 300, Jangan-gu, Suwon, 440-746, Korea
4Disaster Management HPC Technology Research Center, Korea Institute of Science and Technology Information, Daejeon, 305-806, Korea
5Nizhny Novgorod State Technical University n.a. R.E. Alekseev, Nizhny Novgorod, 603950, Russia
6Institute of Applied Physics, Nizhny Novgorod, 603950, Russia
Abstract. The tsunami generated on 12 July 1993 by the Hokkaido–Nansei–Oki earthquake (Mw = 7.8) brought about a maximum wave run-up of 31.7 m, the highest recorded in Japan during the 20th century, near the Monai Valley on the west coast of Okushiri Island (Hokkaido Tsunami Survey Group, 1993). To reproduce the extreme run-up height, the three-dimensional non-hydrostatic model (Flow Science, 2012), referred to here as the NH-model, has been locally applied with open boundary conditions supplied in an offline manner by the three-dimensional hydrostatic model (Ribeiro et al., 2011), referred to here as the H-model. The area of the H-model is sufficiently large to cover the entire fault region with one-way nested multiple domains. For the initial water deformation, Okada's fault model (1985) using the sub-fault parameters is applied.

Three NH-model experiments have been performed, namely without islands, with one island and with two islands. The experiments with one island and with two islands give rise to values close to the observation with maximum run-up heights of about 32.3 and 30.8 m, respectively, while the experiment without islands gives rise to about 25.2 m. The diffraction of the tsunami wave primarily by Muen Island, located in the south, and the southward topographic guiding of the tsunami run-up at the coast are, as in the laboratory simulation (Yoneyama et al., 2002), found to result in the extreme run-up height near Monai Valley. The presence of Hira Island enhances the diffraction of tsunami waves but its contribution to the extreme run-up height is marginal.


Citation: Kim, K. O., Kim, D. C., Choi, B. H., Jung, K. T., Yuk, J. H., and Pelinovsky, E.: The role of diffraction effects in extreme run-up inundation at Okushiri Island due to 1993 tsunami, Nat. Hazards Earth Syst. Sci., 15, 747-755, https://doi.org/10.5194/nhess-15-747-2015, 2015.
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The 1993 Hokkaido tsunami brought about a maximum wave run-up of 31.7m. To reproduce the extreme run-up height, a three-dimensional non-hydrostatic model has been locally applied with open boundary conditions supplied in an offline manner by a three-dimensional hydrostatic model. The diffraction of the tsunami wave primarily by islands was found to result in the extreme run-up height as in the laboratory simulation.
The 1993 Hokkaido tsunami brought about a maximum wave run-up of 31.7m. To reproduce the extreme...
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