2025 Volume 81 Issue 13 Article ID: 24-13486
The 2024 Noto Peninsula Earthquake (MJ=7.6) caused widespread liquefaction-induced ground deformation throughout the Noto Peninsula and Hokuriku region, with ground flow due to liquefaction particularly concentrated along the inland edge of the Uchinada Sand Dunes. This report summarizes the characteristics of ground deformation observed in Ohsaki, Kahoku City, including the topographic features of the initiation and convergence points of the ground flow areas. The Uchinada Sand Dunes are classified into old new dunes, with the new dunes characterized by low converted N-values and shear wave velocities, and a shallow groundwater level. The grain size distribution of the sand ejected from the ground was found to closely match that of the new dunes. To understand the impact of groundwater distribution differences on liquefaction-induced flow displacement, a residual deformation analysis was conducted. The results indicate that when groundwater is inclined along the surface, the thickness of the liquefied layer in the new dunes increases, with the groundwater gradient significantly amplifying flow deformation, consistent with the observed cracks and upheaval at the site.
