Distribution of seismicity hazard levels using PGA analysis with the PSHA method in the Ciletuh Geopark Area, Sukabumi, Indonesia

Abstract

The regional structure in Java Island, Indonesia, was influenced by the collisional activity of the Eurasian and Indo-Australian plates, which resulted from mélange rocks outcrops in Ciletuh. Ciletuh is one of the geotourism conservation areas included in the UGG (UNESCO Global Geoparks). This area is in the path of the Cimandiri Fault and the Sunda Strait Megathrust, resulting in a unique geological diversity and a place where the oldest rocks are exposed in West Java. In addition, the potential impact of seismicity on the Ciletuh geopark area is quite significant. The potential for seismicity can be analyzed and calculated. In this study, PGA (Peak Ground Acceleration) analysis on bedrock was conducted using the PSHA (Probabilistic Seismic Hazard Analysis) method. The data used for the PSHA method is in the form of background, fault, and megathrust provided by the National Earthquake Study Center (PuSGeN). This research shows that the PGA value in the Ciletuh Geopark area is influenced by how close it is to the location of the earthquake source. Pelabuhanratu Subdistrict has the highest PGA value based on all earthquake sources when combined.