Monitoring Slow Slip Events in the Nankai Trough Region Using PSInSAR
Ching-Lun Lin (1), Chung-Pai Chang (2)

Center for Space and Remote Sensing Research, National Central University, Taiwan

Abstract

The Nankai Trough, an active subduction zone off southern Japan, poses a significant seismic hazard due to its potential for generating destructive megathrust earthquakes. Episodic slow slip events (SSEs), which occur aseismically along the plate interface, are key indicators of stress accumulation and interplate coupling. While Japan^s dense GNSS network has enabled reliable SSE detection, its cost and limited applicability in other tectonic regions underscore the need for alternative approaches. This study evaluates the capability of Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) as a complementary technique, offering centimeter-scale displacement sensitivity, broad spatial coverage, and sufficient temporal resolution. Using Sentinel-1 SAR data (2017-2025), processed through ESA^s SNAP and StaMPS software, the analysis focuses on detecting subtle crustal deformation in the Nankai Trough region. PSInSAR-derived signals are cross-validated against GNSS and seismicity data to assess their spatial extent and temporal evolution. The results highlight the potential of PSInSAR for monitoring slow tectonic transients in subduction zones, thereby contributing to a more comprehensive understanding of the seismic cycle and long-term hazard assessment in the Nankai Trough.

Keywords: Slow earthquake, PSInSAR, Nankai Trough, Slow slip events, StaMPS

Topic: Topic B: Applications of Remote Sensing