Revisiting source modeling in complex tectonic environments for PSHA: A Taiwan case study

Jessica D. Velasquez, Delphine D. Fitzenz, & Natanya B. Porto

Published 2019, SCEC Contribution #9099

All six Taiwan cities with populations of over one million people are located less than 10 km from at least one known, active seismogenic structure. The importance of characterizing the hazard associated with these structures is critical for understanding the risk in Taiwan, a country not unfamiliar with large, damaging earthquake. The complexity of the tectonics in this region make it well-suited for an investigation into the dynamics of how systems of faults and subduction interfaces may interact and accommodate plate motions. Here we build on and explore the recent Taiwan Earthquake Model Probabilistic Seismic Hazard Assessment study (TEM PSHA2015; Wang et al., 2016). We show the variation in hazard that can result from the inclusion of sub- and multi-fault ruptures. The systems of crustal faults across Taiwan translate the motions between the two opposite-dipping subduction zones at either end of the island. We will therefore also explore how coupling assumptions affect the overall moment budget of the system. We present end member cases to showcase the hazard variability and show how these variations can translate into significant differences in risk.

Citation
Velasquez, J. D., Fitzenz, D. D., & Porto, N. B. (2019). Revisiting source modeling in complex tectonic environments for PSHA: A Taiwan case study. Poster Presentation at Seismological Society of America Annual Meeting.