Description
Regional seismic risk assessment has emerged as a growing research area in the past decade, driven by the rapid expansion of urban centers situated near active fault systems (Kim and Kim, 2024). The process of regional risk evaluation entails two core components: (1) assessing the structural vulnerability and exposure of assets within a region and (2) evaluating the seismic hazard that may affect those assets. This study focuses primarily on the second component, the estimation of regional seismic hazard. Regional probabilistic seismic hazard analysis (RPSHA) leverages single site-specific approach, estimating exceedance rates for multiple sites and generating regional hazard fields. To model regional hazard, it requires assessing three main parameters: (1) seismic source characterization, (2) ground motion assessment, and (3) uncertainty estimation trough spatial correlation models. To assess IM regional fields, Monte Carlo-based simulation method is the preferred tool and the one applied in this work (Baker et al., 2021). This study presents the comparison of the uncertainties in three IMs: PGA, Sa(T=1s) and Saavg (0.2T-1.5T). Each IM is assessed with two Chilean GMMs (Idini et al., 2017, Montalva et al., 2017) and three subduction global GMMs (Parker et al., 2022, Abrahamson and Gulerce, 2022, and Kuehn et al., 2023), and uncertainties are propagated with spatial correlation models for PGA and Sa(T) (proposed by Aldea et al., 2022) and for Saavg (proposed by Heresi and Miranda, 2021).Two case studies over the Metropolitan area in Chile are developed. The first one is composed of a probabilistic analysis in a 25-points grid separated at every 0.1°, for three Vs30 values (350, 500, and 900 m/s) and three correlation levels (without, real and perfect correlation among points). The second one establish a deterministic analysis for the 2010 Mw=8.8 Maule earthquake, comparing IMs measures in five stations over the region (Castro et al., 2022) with the IM estimations for the same three correlation levels in case one.
| Period | Oct 2025 |
|---|---|
| Held at | GIASIS, Chile |
| Degree of Recognition | National |