Interpretation and classification of landslides triggered by the 2024 Noto Peninsula Earthquake (M7.6) for landslide inventory
摘要
After the occurrence of the Noto Peninsula Earthquake (M7.6) on 1 Jan 2024 in NW Japan, the Geospatial Information Authority of Japan published aerial photos and a landslide inventory of the affected region with interpretations online. However, the inventory did not classify the scar (source of landslide), transported, and accumulated areas of the landslide mass, necessitating a more comprehensive interpretation of the published photos. This study focused on an 80-km2 area located on the boundary of the cities of Noto and Suzu, where many landslides were triggered by the 2024 earthquake. The landslides were classified into six types and tallied. A total number of 809 scars (118.38 ha), 209 clearly interpreted landslide bodies (153.31 ha), 79 slightly interpreted landslide bodies (32.59 ha), 514 mass-accumulated areas (115.85 ha), 93 mass-transported areas (25.19 ha), and 953 shallow-disrupted landslides (96.29 ha) were recorded. These types were further divided into subtypes, such as scars being classified into deep-seated and shallow-disrupted landslides. A 1-m digital elevation model analysis showed that the slope area ratio increased with the slope angle. The slope area ratio of shallow disruptions (approximately 11%) was higher than that of deep-seated disruptions (approximately 2%) at a slope angle of 85°. Though the study area is limited to the landslide-concentrated area, this reconnaissance study produces a more comprehensive inventory to understand the geological and geomorphological characteristics of the earthquake-induced landslides.