Detection of surface deformation and growth of an active fold induced by the 2007 Niigataken Chuetsu-oki Earthquake using SAR interferometry

Abstract

An interferometric analysis of Synthetic Aperture Radar (InSAR) using PARSAR data of the Advanced Land Observations Satellite (ALOS PALSAR) reveals the spatial pattern of deformation associated with the 2007 Niigataken Chuetsu-oki Earthquake (Mj 6.8). The analysis reveals not only regional deformation in the focal area, but also a narrow uplifted zone (1.5 km in width and 15 km in length) along the axis of an active anticline in the Nishiyama hill, located 15 km east of the epicenter of the mainshock. The deformation provides direct evidence for episodic growth of the fold, triggered by the earthquake. In addition, InSAR data reveal non-tectonic ground deformation, such as soil liquefaction and lateral soil flow in the central part of Kashiwazaki City.