5:15 PM - 6:45 PM
[U15-P69] Comparative Investigation of Tsunami Source Models for the 2024 Noto Peninsula Earthquake Based on Comprehensive Seabed Survey Data
Keywords:Tsunami, 2024 Noto Peninsula Earthquake , Tsunami Source Model, Numerical Simulation, Seabed Survey, Sensitivity analysis
The tsunami that accompanied the Noto Peninsula earthquake (M7.6), which occurred on January 1, 2024, resulted in waves exceeding 5 meters in height along the coast of the Sea of Japan. The faults responsible for generating the tsunami are believed to be offshore of Noto. Specifically, the NT1 to NT6 faults, examined by the Sea of Japan Earthquake & Tsunami Survey Project (Sato et al., 2021), and the F42 and F43 faults, considered by the Ministry of Land, Infrastructure, Transport, and Tourism, have been suggested. Their movements are presumed to have caused the tsunami. However, many details remain unclear, such as how much each fault moved and the impact of submarine landslides on the tsunami. Amidst this, Fujii and Satake (2024) have used inversion methods to estimate the slip amounts of the NT1 to NT6 faults and have proposed a model that somewhat aligns with the time-series waveforms recorded by tidal gauges along the coast of the Sea of Japan. On the other hand, the Civil Engineering Society's Coastal Engineering Committee has published measurements taken along the coasts of Ishikawa, Toyama, and Niigata Prefectures (Yui et al., 2024). According to their findings, the tsunami heights were approximately 4 to 5 meters along the eastern and western coasts of Ishikawa Prefecture, around 1 to 2 meters along the coasts of Toyama and Niigata Prefectures, except for Joetsu, where locally, the tsunami exceeded 5 meters.
A comprehensive tsunami source model that could explain the tsunami observed along these coastal areas has yet to be proposed. Meanwhile, seabed surveys have been conducted to elucidate the underwater earthquake faults, gradually revealing the changes in topography before and after the earthquake and the characteristics of the seismic faults.
Therefore, this study aims to elucidate the tsunami generation mechanism by performing numerical calculations and sensitivity analysis, altering the dip angle and slip amounts of faults based on current information from seabed surveys and including localized submarine landslides. The non-linear dispersive wave model JAGURS was used for the numerical calculations. The results suggest that the slip amounts of the faults on the eastern side of the offshore area of Noto might be small and that relatively large tsunami sources near the boundary between the east and west faults could explain the observed tsunami heights in Joetsu.
A comprehensive tsunami source model that could explain the tsunami observed along these coastal areas has yet to be proposed. Meanwhile, seabed surveys have been conducted to elucidate the underwater earthquake faults, gradually revealing the changes in topography before and after the earthquake and the characteristics of the seismic faults.
Therefore, this study aims to elucidate the tsunami generation mechanism by performing numerical calculations and sensitivity analysis, altering the dip angle and slip amounts of faults based on current information from seabed surveys and including localized submarine landslides. The non-linear dispersive wave model JAGURS was used for the numerical calculations. The results suggest that the slip amounts of the faults on the eastern side of the offshore area of Noto might be small and that relatively large tsunami sources near the boundary between the east and west faults could explain the observed tsunami heights in Joetsu.