Site-Specific Probabilistic Seismic Hazard Analysis for Sakarya Province

This study presents a site-specific Probabilistic Seismic Hazard Analysis (PSHA) for Sakarya Province, located near the North Anatolian Fault Zone. The earthquake catalog (1900–2023) was homogenized, declustered, and analyzed for completeness using ZMAP. Site-specific PSHA was performed with the OpenQuake engine. Seismic sources were modeled using ESHM20 area and fault sources within a logic-tree framework. A hybrid Vs30 model combining 2044 in-situ measurements and USGS data was developed to represent local site conditions. Results show that local hazard estimates exceed TBEC-2018 and ESHM20, particularly in basin areas, highlighting the importance of high-resolution site characterization for reliable seismic hazard assessment.