MECHANICAL INTERPRETATION USING LOCAL SAFETY FACTOR OF SURFACE RUPTURES CAUSED BY THE 2024 NOTO PENINSULA EARTHQUAKE

Abstract

 In this paper, surface ruptures caused by the 2024 Noto Peninsula earthquake were discussed mechanistically based on the stress changes in the surface rock mass due to crustal deformation. The possibility of rupture of the surface rock mass was evaluated using the local safety factor, which is defined as the ratio of the shear strength to the shear stress, calculated by the elastic theory of dislocations. The results suggest that the surface ruptures near the Wakayama River in Suzu City are located in a region where the local safety factor is less than 1, and are secondary faults. On the other hand, the surface rupture observed near the Togigawa-Nangan fault has a local safety factor greater than 5, suggesting that it is not a secondary fault.