Satrio Muhammad Alif, Ongky Anggara, Redho Surya Perdana, Rizki Wulandari, Yudha Styawan
Southern Sumatra, Indonesia, is a tectonically active region influenced by the Sunda subduction zone and the Sumatran Fault Zone (SFZ), yet its earthquake potential and seismic hazard have not been comprehensively assessed using geodetic data. This study investigates how different GNSS velocity sets, comprising continuous, periodic, and synthetic data, affect the estimation of strain, earthquake potential, and probabilistic seismic hazard. Postseismic deformation is corrected using a viscoelastic model to isolate interseismic signals. Principal strain is computed across six tectonic zones, and earthquake potential is quantified using geodetic and seismic moment rates. The derived moment magnitudes range from Mw 5.9 to Mw 7.2 across the zones. The PSHA incorporates geodetically constrained magnitude–frequency distributions and is implemented using OpenQuake. Results show that the geodetically constrained model yields peak ground acceleration (PGA) values up to 0.57 ± 0.11 g, significantly lower than the 1.1 ± 0.1 g from the non-constrained model, highlighting the overestimation risk in models that neglect aseismic processes. These findings suggest that partial creeping along the SFZ may reduce short-term seismic hazard. The study underscores the importance of integrating geodetic observations into seismic hazard assessments, especially in regions with complex fault segmentation and limited historical earthquake records. © 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Geomatics Engineering, Institut Teknologi Sumatera, Indonesia; Geophysics Engineering, Institut Teknologi Sumatera, Indonesia