Impacts of bathymetry on the propagation of tsunamis in the Sea of Japan

Ray tracing of tsunamis generated at the Sea of Japan (SOJ) was performed to investigate far-field tsunami propagation in a semi-enclosed sea with complicated bottom features. This study focused on analyzing the propagation of the tsunami generated by the 2024 Noto Peninsula Earthquake that emerged in the southern SOJ, which differed from previously recorded large tsunami events that originated in the northern part of the SOJ. The tsunami propagation path and traveling time were estimated by predicting the wave refraction according to Snell’s Law. The numerical runs were made under the setting of four major tsunami events that occurred in the SOJ, and the calculated arrival time of the initial wave at the coast agreed well with the observed values. The trajectories of tsunami waves in the SOJ depend greatly on the meridional position of the wave source. In the case of the Noto Earthquake, the tsunami generated at the western and eastern parts of the rupture zone behaved differently, mainly due to the presence of the deep Toyama Submarine Canyon situated on the eastern side of the tsunami source. The findings of this study may aid in interpreting the observed or simulated results regarding tsunami propagation in the SOJ.