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Smoothing-Based Aftershock Probabilistic Seismic Hazard Assessment Using the Spatiotemporal ETAS Model


Abstract Probabilistic seismic hazard analysis (PSHA) is generally based on computing time-invariant occurrence rates of mainshocks using the Poisson process. However, aftershock probabilistic seismic hazard analysis (APSHA) allows for assessing time-varying aftershock occurrence rates within a short-term seismic hazard mitigation framework. Our proposed methodology of APSHA develops a smoothing-based analytical formulation to capture the spatial distribution and temporal evolution of aftershock sequences using the spatiotemporal epidemic-type aftershock sequence model. This approach is tested on case studies of the 2013 Bushehr, 2021 and 2022 Hormozgan seismic events, and characterizes the aftershocks’ hierarchical structure to improve the reliability of aftershock hazard assessments. Then, the results of APSHA (aftershock ground-motion hazard at specific sites) based on smoothing are compared with conventional PSHA (pre-mainshock ground-motion hazard at specific sites). This comparative analysis highlights the importance of considering aftershock effects when assessing ground-motion hazards because PSHA does not fully account for aftershock hazard increases following major earthquakes.
Authors Elham Shokrgozar-Yatimdar University of Wyoming , Saman Yaghmaei‐Sabegh ORCID , Parva Shoaeifar ORCID , Po Chen University of WyomingORCID
Journal Info Seismological Society of America | Bulletin of the Seismological Society of America
Publication Date 12/6/2024
ISSN 0037-1106
TypeKeyword Image article
Open Access closed Closed Access
DOI https://doi.org/10.1785/0120240172
KeywordsKeyword Image Smoothing (Score: 0.59426016)