9:15 AM - 9:30 AM
[SSS11-07] Microtremor observations in Damaged area due to the 2024 Noto Peninsula Earthquake: Noto Town, Ukawa, Matsunami, and Ushitsu; Nanao City, Tazurihama area
Keywords:microtremor, H/V, S-wave velocity, the 2024 Noto Peninsula Earthquake, Damaged area
The Noto Peninsula earthquake that occurred on January 1, 2024 caused extensive damage in the Noto region of Ishikawa Prefecture near the epicenter. In this study, microtremor observations were conducted in the damaged areas where collapsed houses were concentrated in Ukawa, Matsunami, and Ushitsu Noto Town, and Tazuruhama, Nanao City. Three-component single-point microtremor observations were conducted at intervals of approximately 100 m: 48 points in Ukawa, Noto Town; 46 points in Matsunami, Noto Town; 31 points in Udezu, Noto Town; and 63 points in Tazuruhama, Nanao City. Array observations were conducted at 2 sites in each area, for a total of 8 sites.
The H/V characteristics of the earthquake were clear peaks in all areas, and the predominant period was 0.2 to 3 s. The predominant period was 1 to 3 s, especially in areas where collapsed houses were concentrated. Especially in the area where the collapsed houses were concentrated, the excitatory period was 1 to 3 s. The subsurface structure was characterized by Vs=100 to 200 m/s. The H/V values were also high in the area where the collapsed houses were concentrated, with the excitatory period ranging from 0.2 to 3 s. TAs for the ground structure, it was found that the soft ground with Vs=100-200m/s was thicker. In addition to amplification of the strong ground motion due to soft layers, nonlinear ground response may have had a significant impact on the damage in each region.
The H/V characteristics of the earthquake were clear peaks in all areas, and the predominant period was 0.2 to 3 s. The predominant period was 1 to 3 s, especially in areas where collapsed houses were concentrated. Especially in the area where the collapsed houses were concentrated, the excitatory period was 1 to 3 s. The subsurface structure was characterized by Vs=100 to 200 m/s. The H/V values were also high in the area where the collapsed houses were concentrated, with the excitatory period ranging from 0.2 to 3 s. TAs for the ground structure, it was found that the soft ground with Vs=100-200m/s was thicker. In addition to amplification of the strong ground motion due to soft layers, nonlinear ground response may have had a significant impact on the damage in each region.