Application of neodeterministic seismic hazard analysis to Sumatra

Abstract This work is about the application of neo-deterministic seismic hazard assessment (NDSHA) methodology at two different scales: the regional scale, covering Sumatra, whose results are shown by the NDSHA maps, and the local scale, covering Banda Aceh city, whose result is the microzonation map of Banda Aceh City. NDSHA addresses some issues largely neglected in a traditional hazard analysis, that is, how crustal properties affect attenuation: ground motion parameters are not derived from overly simplified attenuation relations, but rather from the synthetic time histories. Starting from the available information on the Earth's structure (mechanical properties), seismic sources, and the level of seismicity of the investigated area, it is possible to estimate PGA, PGV, and PGD or any other parameter relevant to seismic engineering, which can be extracted from the physics-based computed signals. The implementation of NDSHA has been challenging due to the complicated tectonic setting, high seismicity, and the not-well-known but complex structural model of Sumatra; thus, the usual flow of the NDSHA analysis at a regional scale has been optimized for its application to this region. The NDSHA study that has been successfully carried out on Sumatra represents a milestone for improving the accuracy of the seismic hazard assessment map throughout Indonesia, a country that is exposed to a very high seismic risk.