FIELD INVESTIGATIONS, NUMERICAL MODELING AND BAYESIAN ANALYSIS OF EARTHQUAKE, TSUNAMI AND LANDSLIDE RISK IN EASTERN INDONESIA
The Banda Islands, which are surrounded by 270º of subduction zones, offer historical data regarding 400 years of earthquakes and associated tsunamis. One of the best-documented earthquake and tsunami events occurred in 1852. A new methodology involving Bayesian statistical inversion is used to reconstruct the most likely source parameters of this event. This method may also be applied to forecast earthquake and tsunami risks from other historical events worldwide.
Our investigation of Banda Api volcano over a 6-year time span revealed an active normal fault scarp that cuts through the summit. The last eruption in 1988 extruded lava flows from the fault zone along the flanks of the volcano, delineating a zone of weakness along which a future sector collapse may occur. A numerical simulation of this event produces a tsunami with up to 76 meters of run-up that inundates nearly every human-occupied part of the islands. The same methodology is used to reconstruct a landslide tsunami that occurred on the north coast of Ambon in 1674 with a 100 meter of run up.
Our work also involves community outreach in these areas to improve local geohazard education and preparedness.