[S-GD03] 地殻変動

[SGD03-P01] 立山火山地獄谷における2016～2024年の長期的地盤変動

*堀田 耕平¹ (1.富山大学)

キーワード：立山火山、地獄谷、水準測量、InSAR、Sentinel-1、GNSS

Leveling surveys in Jigokudani Valley, located in the Midagahara area of the Tateyama Volcano, have been conducted by the University of Toyama every summer since 2015. The leveling routes were first established in 2015, revised in 2016 (Hotta et al., 2022), and further expanded in 2023. Between 2016 and 2024, an uplift of up to 4.1 cm was detected in Kajiya Jigoku, the central area of Jigokudani Valley, while subsidence of up to 6.2 cm was observed in the northern and eastern areas of the valley. Interferometric Synthetic Aperture Radar (InSAR) analysis using Sentinel-1 SAR data from the European Space Agency also revealed similar deformation trends. Global Navigation Satellite System (GNSS) surveys have also been conducted in the valley since 2020. Their time series with respect to GNSS Earth Observation Network System (GEONET) station 041138, conducted by the Geospatial Information Authority of Japan (GSI), are consistent with the results of annual leveling surveys.