第107回総合防災セミナー(11/7)
- セミナー
| 開催期間 | 2025.11.07 15:00 ～ 17:00 |
|---|---|
| 場所 | 宇治キャンパス本館E-417D および オンライン |
| 対象 | 研究者、学生、一般 |
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[Date & Time]
11月7日（金）15:00-17:00
[Venue]
宇治キャンパス本館E-417D および オンライン
参加登録はこちら（オンライン参加の場合、11月5日（水）
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[Title]
Improving tsunami source models in the context of advancing understanding of earthquake sources.
[Language]
English
[Abstract]
Traditionally the so-called static tsunami sources were used in tsunami modelling. According to this approach, it was assumed that during an earthquake, the deformation of the seafloor occurs instantaneously, and that initial displacement of the ocean surface is exactly the same as the seafloor displacement.
The first limitation of this approach is that local irregularities of the seafloor displacement, which in reality are smoothed out by the water layer, remain in the model and saturate the synthetic tsunami. To avoid this, it is necessary to calculate the smoothed initial ocean surface displacement using non-orthogonal curvilinear sigma coordinates.
The second limitation of the static approach is that it neglects the effect of fault rupture propagation on tsunami generation. This can lead to significant underestimations of tsunami. The importance of time-dependent tsunami sources will be explained using our results for the Illapel event (2015/09/16).
Finally, strong ground motions simulations for the Noto-Hanto earthquake (2024/01/01) will be presented. Strong ground motion simulations was performed using the spectral element method. In the context of the tsunami discussion, it is worth noting that seismic waves themselves under certain conditions are able to generate the waves in the ocean, as was observed during the catastrophic 2011 Tohoku event.
[Short bio]
PhD Kirill Sementsov is an Earth-Scientist graduated from Lomonosov Moscow State University. He had a 2 years postdoctoral stay in Hokkaido University. From April 2025 he is working as a specially-appointed assistant professor in the Sophisticated Earthquake Risk Evaluation Section, DPRI. His research interests are related to the earthquake and tsunami sources, mechanisms of tsunami generation and simulation of the strong ground motion using spectral element method (SPECFEM3D).