2024 年 24 巻 7 号 p. 7_27-7_32
We applied NIOM analysis to the earthquake records at the KiK-net Togi site to examine nonlinear behavior of the ground during the 2024 Noto Hanto earthquake. Results revealed that (1) S-wave propagation times increased from 0.2365 s (NS) and 0.2333 s (EW) before the mainshock to 0.3136 s and 0.3245 s, respectively, during principal motion, and (2) S-wave propagation times at the end of the waveform were larger than those before the mainshock by 6 to 6.5%. In addition, a SHAKE91 analysis indicated that (3) the effect of nonlinear behavior was remarkable in the soil layer from GL −28 to −50 m.
