Assessing Geological and Seismic Hazards of Malili-Matano Region, East Luwu Regency, Sulawesi: A preliminary study for CCS and Strategic Infrastructure Planning

Understanding the seismotectonic characteristics and seismic hazards of the Malili-Matano Region (MMR) in Sulawesi is crucial due to its proximity to active faults, including the Matano Fault Zone (MFZ) and surrounding fault systems. These geological conditions pose significant risks to infrastructure development, particularly Carbon Capture and Storage (CCS) facilities , which require a thorough assessment of seismic hazards. This study integrates seismotectonic mapping and Probabilistic Seismic Hazard Analysis (PSHA) to evaluate earthquake risks, with a particular focus on spectral acceleration (PSA) values that influence structural resilience. The results indicate that MMR exhibits complex fault interactions , leading to elevated Peak Ground Acceleration (PGA ) and Spectral Acceleration (PSA) values, with PSA Ss = 1.10 g at 0.2 seconds and S1 = 0.55 g at 1 second for Site Class SB under a 2% probability of exceedance in 50 years (2500-year return period). These seismic hazard estimates suggest that structural design in the region must adhere to Seismic Design Category D standards, including reinforced foundations and real-time ground motion monitoring to enhance CCS infrastructure safety. The study underscores the importance of continuous seismic monitoring, hazard mitigation strategies, and risk communication for infrastructure resilience in seismically active environments. The findings contribute to a refined understanding of seismotectonic behavior in MMR and its implications for CCS site selection and long-term sustainability.