Post-event survey and numerical simulation of the tsunami inundation caused by the 2024 Noto Peninsula Earthquake in Hegurajima Island, Japan

This is the authors' abstract. We don't add key points for this paper.

The 2024 Noto Peninsula Earthquake generated a tsunami that concentrated around Hegurajima Island due to wave refraction. However, disruptions in marine transport hindered on-site surveys, resulting in insufficient tsunami run-up and inundation data in previous studies. Lack of comprehensive field data limited the understanding of tsunami behavior in this region. This study presents a more detailed and extensive field survey of tsunami inundation and run-up heights covering the whole island. Our field measurements, utilizing a total station, revealed significant variations in tsunami height across different areas of the island. The inundation and run-up heights were significantly lower in breakwater-protected areas compared with those in unprotected areas, with a reduction rate of 40–50%. The maximum run-up height recorded was 6.5 m in the northern region. Moreover, we conducted numerical simulations based on the nonlinear long-wave theory to clarify further the characteristics of tsunami propagation and inundation. The simulation results closely matched field survey results, effectively replicating key inundation features, such as debris distribution and house damage. A comparison of survey findings and numerical simulations provided insights into the physical mechanisms governing the island’s complex inundation patterns.