Abstract by Claire Ashcraft
Field investigations, numerical modeling and Bayesian analysis of earthquake, tsunami and landslide risk in eastern Indonesia
This investigation helps quantify the risk of natural hazards on the Indonesian islands of Lombok, Ambon, and Banda. Seismic measurements were acquired to determine variations in Vs30 (shear-wave velocity to 30m depth), which is used as a proxy for MMI. Vs30 and MMI of modern and historical earthquakes are then correlated with the goal of mapping shaking susceptibility by location. The Banda Islands are surrounded by 270 degrees of subduction zones and offer historical data regarding centuries of earthquakes and tsunamis. A new methodology involving Bayesian statistical inversion was used to reconstruct the source parameters of an earthquake and tsunami that occurred there in 1852. Additionally, investigation of Banda Api volcano in the Banda Islands revealed a fault along which a sector collapse may occur. A numerical simulation of this event produces a tsunami with up to 76m of run-up. The same technique is used to reconstruct a major landslide tsunami that occurred on Ambon in 1674.