Ongky Anggara, Irwan Meilano, Satrio Muhammad Alif, Susilo Susilo, Agustinus Bambang Setyadji
Central Sumatra, Indonesia, is historically known for its significant seismic activities, most notably the devastating 1883 earthquake. In this study, we measured the interseismic deformation using continuous GNSS observation data for three years from 2018 to 2021.5. The results show that the derived velocity fields indicate that the Central Sumatra deformation is primarily characterized by crustal strain shortening due to interaction between the India-Australian plate and the Sundaland plate. High strain values are observed along the Sumatran Fault Zone (SFZ), which is characterized by a history of significant seismic activity. Interseismic locking is divided into two segments. Segment A, located in the northern part of Siberut Island has an estimated moment magnitude of MW7.44 with a return period of 200 years leading to a potential earthquake magnitude of MW8.98. Segment B in the southern part of Siberut Island has an estimated moment magnitude of MW7.26 with a return period of 200 years, resulting in a potential earthquake magnitude of MW8.79. The findings highlight critical seismic hazard implications, emphasizing the potential for a major earthquake in the Central Sumatra. © 2025 Institute of Seismology, China Earthquake Administration
Department of Geomatics Engineering, Institut Teknologi Sumatera, South Lampung, Indonesia; Faculty of Earth Sciences and Technology, Institute of Technology Bandung (ITB), Bandung, Indonesia; National Research and Innovation Agency (BRIN), Jakarta Pusat, Indonesia; Geodesy and Geomatics Engineering, Faculty of Earth Science and Technology, Institut Teknologi Bandung, Bandung, Indonesia