Probabilistic tsunami hazard analysis of Batukaras, a tourism village in Indonesia

Abstract

Indonesia's location in the middle of tectonic plates makes it vulnerable to earthquakes and tsunamis, especially in the megathrust zone around the island of Sumatra and the southern part of the island of Java. Research shows a seismic gap in southern Java, which poses a potential threat of megathrust earthquakes and tsunamis, impacting coastal areas such as Batukaras in West Java, a popular tourist destination. To prepare for disasters, probabilistic tsunami hazard analysis (PTHA), which focuses on seismic factors, was carried out by modelling tsunamis on 3348 sub-segments of 4 large megathrust segments in the south of Java. Stochastic earthquake modelling was used to simulate the occurrence of a tsunami from an earthquake with Mw 6.5 to the highest potential magnitude. This research shows that the PTHA in Batukaras reveals varying heights of 0.84, 1.63, 2.97, and 5.7 m for each earthquake return period of 250, 500, 1000, and 2500 years, respectively. The dominant threat arises from the West Java-Central Java megathrust segment, emphasising the importance of preparedness, although the annual probability of tsunamis is generally low. Our study will deepen knowledge of tsunami hazards associated with megathrust activities near Batukaras for mitigation planning and decision-making, and it can become a reference for similar coastal tourist areas.