107th Sogo Bosai seminar (Nov, 7)

  • Date : 07 Nov. 2025 15:00 - 17:00
  • Seminar
Date 07 Nov. 2025 15:00 - 17:00
Place E-417D of Main building, Uji campus and Online
Target Researcher, Student, General
We are pleased to announce the 107th Sogo Bosai Seminar (Nov. 7, Friday) as follows.
Dr. Kirill at the Sophisticated Earthquake Risk Evaluation Lab will deliver the lecture on
“Improving tsunami source models in the context of advancing understanding of earthquake sources.”
We look forward to your participation. This seminar will be held in English.

 

[Date & Time]
November 7, Friday, 15:00-17:00

 

[Venue]
E-417D of Main building, Uji campus and Online
If you will attend via online, please register yourself by November 5, 9:00am: https://forms.gle/yExbjxToArfcyFwy5

 

[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).