ASSESSMENT ON THE POTENTIAL OF TSUNAMI RISK IN SUNDA STRAIT COASTS DUE TO SEISMICITY IN THE SUNDA MEGATHRUST SUBDUCTION ZONE (CASE STUDY: CILEGON CITY AND TANJUNG LESUNG)

• Main Author: Syakura, Salsabila
• Format: Final Project
• Language: Indonesia
• Subjects: Karya Umum
• Online Access: https://digilib.itb.ac.id/gdl/view/51958
• Institution: Institut Teknologi Bandung

Based on the map by Tim Pusat Studi Gempa Nasional in 2017, one of the locations that have the potential to produce earthquakes with large magnitudes is the Sunda Megathrust Subduction Zone, precisely in the Sunda-Banten Strait segment with ???????? = 8.8. It is feared that the potential for an earthquake with a large magnitude will generate a tsunami that will hit the coastal areas of Java Island. Therefore, this research will study the potential of tsunami risk in Sunda Strait Coasts due to seismicity in the Sunda Megathrust Subduction Zone with three hypothetical scenarios and apply a nested grid model in which the smallest level domain is focused on the Cilegon City and Tanjung Lesung area. This tsunami propagation simulation using COMCOT v.1.7 with the input of bathymetry and topography data from BATNAS and DEMNAS. This tsunami propagation simulation was run for two hours. The simulation shows that the maximum tsunami height recorded at the verification points in Scenario-3 (extreme scenario, Mw = 9.2) in Cilegon City and Tanjung Lesung is 3.34 m and 8.23 m. Then, the fastest tsunami arrival time in the City of Cilegon and Tanjung Lesung is recorded in Scenario-3 (???????? = 9.2) with a value range of 62 - 74 minutes and 46 - 50 minutes. The transformation of the tsunami waves (refraction, reflection, and diffraction) causes the tsunami height to vary along the Sunda Strait Coasts. Furthermore, the maximum inundation in Cilegon City and Tanjung Lesung is 4.5 m and 14.4 m. The potential for tsunami hazards based on inundation in Cilegon City and Tanjung Lesung is at a low and very high hazard level, respectively. By paying attention to the hazard and vulnerability aspects, Cilegon City and Tanjung Lesung have the potential to be included in Tsunami Risk Category III.