HYPOTHETICAL MODELING OF TSUNAMIS DUE TO VOLCANIC ACTIVITY IN THE TEON-NILA-SERUA ISLANDS, MALUKU PROVINCE Riyadi Zakia Syahrulloh (a*), Hamzah Latief (a) , Karina Aprilia Sujatmiko (a)
(a) Oceanography, Faculty of Earth Sciences and Technology, Bandung Institute of Technology (ITB)
Jl. Ganesha 10, Bandung, West Java 40132, Indonesia
*Corresponding author, E-mail:riyadizakia111[at]gmail.com
Abstract
Maluku Province, located along the Pacific Ring of Fire, is prone to volcanic activity, which poses significant risks. One such risk involves volcanoes like Mount Laworkawra, which last erupted in 1968 on Nila Island. To anticipate potential tsunamis resulting from volcanic activity, a hypothetical analysis using numerical simulations is essential for effective mitigation planning.
This study employs the COMCOT (Cornell Multi grid Coupled Tsunami Model) to simulate tsunamis triggered by underwater landslides, utilizing the Non linear Shallow Water Equations (NSWE) and a nested domain approach with up to 10 layers. Bathymetric data from the International Hydrographic Organization (IHO) and National Topographic data (DEMNAS) were used. Five scenarios were simulated, varying the landslide volumes based on historical events such as the 1660 Teon Island tsunami (2.75 km^3), the 2018 Anak Krakatau tsunami (2.8 km^3), the 1871 Mount Ruang eruption (5.28 km^3), and estimated landslide prone areas around Nila Island.
The simulation results indicate that at the tsunamis source near Nila Island, the splash height reached up to 200 meters. As the tsunami propagated towards the nearest island, Teon, the wave height decreased to 13 meters, as recorded by the observation station. The fastest tsunami propagation time was 3.5 minutes, while the slowest propagation was toward Kei Kecil Island, taking 39 minutes and reaching a height of 0.32 meters. The study concludes that tsunamis caused by landslides in this region are likely to be local but highly destructive near the source, particularly around Serua, Nila, and Teon Islands. In contrast, more distant areas like Damar, Romang, Moa, Babar, Jendena, and Kei Kecil Islands would experience significantly lower impact.
Keywords: tsunami hazard, volcanic tsunami, underwater landslide, Nila Island, COMCOT
