Development of Peak Ground Motion Acceleration Map of Surabaya City based on Probabilistic Seismic Hazard Analysis

Abstract The city of Surabaya is a densely populated city with a diverse array of structural and infrastructural developments. In addition to these, the city is equipped with vital systems that support daily life; however, it faces a significant risk of earthquake disasters. Rapid urban development and population growth further exacerbate this risk. This study aims to implement preventive and mitigation strategies through the application of earthquake-resistant building regulations, guided by Probabilistic Seismic Hazard Analysis (PSHA). The PSHA approach incorporates various data sources, including seismicity background data, fault geometry, and subduction zone information within a 500-kilometer radius of the study area. The analysis computes Peak Ground Acceleration (PGA) values at bedrock, considering a 2% probability of exceedance over a 50-year duration. Preliminary results indicate that the PGA values on bedrock for Surabaya range from 0.314 to 0.538 g. For a period of 0.2 seconds, the values range from 0.759 to 1.308 g, while for a period of 1 second, they range from 0.192 to 0.321 g. Future studies will expand this analysis to include other major cities across Indonesia.