5:15 PM - 6:45 PM
[U15-P95] Estimation of ground surface displacements caused by 2024 Noto Peninsula earthquake, using differential LiDAR DEM analysis
Keywords:Airborne LiDAR survey, surface displacement, 3D image matching analysis
A wide-area crustal deformation was observed in the northern part of the Noto Peninsula following the 2024 Noto Peninsula earthquake. In this study, we conducted a difference analysis using a numerical geomorphologic image analysis method based on airborne LiDAR topographic data acquired before and after the earthquake, to measure the areal surface displacements. As a result, we were able to extract the east-west, north-south, and vertical components of the land surface displacement within the surveyed area, and were able to determine the local land surface displacement that is thought to be caused by slope deformation as well as by wide-area crustal deformation.
The local surface displacement observed near the boundary between Otani-machi and Umatsunagi-machi, Suzu City, and in the hill area of Shibuta-machi, Wajima City, covers an area of about 0.1 to 0.4 km2, and the amount of horizontal displacement is about 2 to 8 m. These displacement areas are considered to be large-scale landslide moving blocks, and it is estimated that secondary collapse of the margins of the moving blocks in the Shibuta River in Shibuta-machi is causing river channel blockage at several points.
In addition, three linear low cliffs were observed crossing the valley-bottom plain of the Wakayama River at Nobutake, Wakayama-machi, Suzu City. According to differential elevation analysis, the area between the low cliffs was uplifted like a horst shape, and the valley wall slopes on both banks at the points where the low cliffs occurred showed a north-south compressive trend of land surface displacements.
The local surface displacement observed near the boundary between Otani-machi and Umatsunagi-machi, Suzu City, and in the hill area of Shibuta-machi, Wajima City, covers an area of about 0.1 to 0.4 km2, and the amount of horizontal displacement is about 2 to 8 m. These displacement areas are considered to be large-scale landslide moving blocks, and it is estimated that secondary collapse of the margins of the moving blocks in the Shibuta River in Shibuta-machi is causing river channel blockage at several points.
In addition, three linear low cliffs were observed crossing the valley-bottom plain of the Wakayama River at Nobutake, Wakayama-machi, Suzu City. According to differential elevation analysis, the area between the low cliffs was uplifted like a horst shape, and the valley wall slopes on both banks at the points where the low cliffs occurred showed a north-south compressive trend of land surface displacements.