[S-SS11] Strong Ground Motion and Earthquake Disaster

[SSS11-27] A source model with asperities for the 2024 Noto Peninsula earthquake

*Atsushi Nozu¹ (1.Port and Airport Research Institute)

Keywords:The 2024 Noto Peninsula earthquake, Strong ground motion, Asperity, Corrected empirical Green's function method

The 2024 Noto Peninsula earthquake caused significant damage to buildings and geotechnical structures. To investigate the damage mechanism of such structures, it is fundamentally important to estimate the ground motions which caused the damage. The spatial variation of ground motions within Noto Peninsula is significant due to the variation of site effects, distance from the asperities, etc. The ground motions which caused the damage is generally unknown. The purpose of this study is to develop a source model which can be used to estimate ground motions at the site of damage. With a trial-and-error approach, the author finally developed a source model with eight asperities. These asperities were intended to reproduce velocity waveforms (0.2-2Hz) and Fourier spectra (0.2-10Hz) at strong motions stations. The locations of the asperities were determined to be consistent with the results of waveform inversion (https://www.pari.go.jp/bsh/jbn-kzo/jbn-bsi/taisin/research_jpn/research_jpn_2024/jr_61.html) as much as possible. Two of the asperities correspond to the initial rupture which proceeded approximately 13 s earlier than the main rupture. The author used the corrected empirical Green's function method (Kowada et al., 1998; Nozu et al., 2009) to calculate strong ground motions. In the presentation, the author will explain why each of these asperities were required.
Acknowledgment: I would like to thank the National Institute for Earth Science and Disaster Resilience for strong motion data.