Monitoring of crustal and ground deformation using Satellite SAR

Abstract

The Geospatial Information Authority of Japan (GSI) conducts monitoring of crustal and ground deformation associated with earthquakes and volcanic activities using satellite Synthetic Aperture Radar (SAR) through analysis techniques such as interferometric analysis and time-series analysis. In recent years, satellite SAR has been used to detect areal crustal deformation accompanying the Earthquake offshore east of Aomori Prefecture (M7.5) that occurred in December 2025 and volcanic activities at Iwatesan since 2024, as well as topographic changes at Ioto following eruptions in 2025. GSI will continue to utilize satellite SAR like ALOS-4 to monitor crustal and ground deformation both during normal times and disasters, thereby advancing the management of national land.