Typical of Tsunami Hazard Potential from Earthquake and Landslide Sources in Palabuhanratu Bay, Indonesia

• Published in: Pure and applied geophysics 2024-05, Vol.181 (5), p.1381-1412
• Main Authors: Setyonegoro, Wiko, Gusman, Aditya Riadi, Hanif, Muhammad, Kurniawan, Telly, Ardhyastuti, Sri, Muqoddas, Muhamad Mahfud, Nakamura, Mamoru, Putra, Purna Sulastya, Husrin, Semeidi, Hanifa, Nuraini Rahma, Nugroho, Septriono Hari, Sudjono, Evie Hadrijantie, Anggono, Titi, Febriani, Febty, Supendi, Pepen, Ramdhan, Mohamad, Martha, Agustya Adi, Tohari, Adrin, Turyana, Iyan
• Format: Article
• Language: English
• Subjects: Debris flow; Earth and Environmental Science; Earth Sciences; Earthquakes; Fault lines; Faults; Geophysics/Geodesy; Landslides; Landslides & mudslides; Nonlinear equations; Ocean floor; Research vessels; Seismic activity; Shallow water; Side scan sonar; Sonar data; Surveys; Tsunami hazard; Tsunamis; Underwater; Weather hazards
• ISSN: 0033-4553; 1420-9136
• DOI: 10.1007/s00024-024-03483-3

Traces of past landslides were found on the seabed of Palabuhanratu Bay, West Java. This landslide is thought to have generated a tsunami, but has never been investigated before. This bay is located around the western part of the Cimandiri Fault which is an active horizontal fault with a length of 100 km. Therefore, it is necessary to study the potential impact of a tsunami in the Palabuhanratu Bay area caused by a combination of local earthquakes and underwater landslides around the bay. Evidence of past landslides was revealed through side-scan sonar data from the underwater research vessel Baruna Jaya IV in Palabuhanratu Bay, Indonesia, in 2020. The data from this survey provides evidence of debris flows (historical landslide data) at the survey site. We simulated 29 tsunami scenarios from combined landslide earthquake sources by solving shallow water nonlinear equations numerically. Tsunami sources from earthquakes are classified into three types, e.g., land faults, sea faults, and combinations of land and sea faults. While the source of the tsunami from the landslide is divided by volume. Combination of the earthquake magnitudes range from M6.80 to M7.85, and the landslide volume ranged from 3.06 × 10 5 m 3 to 2.5 × 10 8 m 3 . This study concludes that in our scenario, the M8.12 type T7 earthquake generates the largest tsunami in the study area, followed by the T6L5 scenario with M7.85 from the Cimandiri Fault and landslide with a total volume of 2.5 × 10 8 m 3 .