Re-thinking site amplification in regional seismic risk assessment
- Probabilistic assessment of seismic hazard and risk over a geographical region presents the modeler with challenges in the characterization of the site amplification that are not present in site-specific assessment. Using site-to-site residuals from a ground motion model fit to observations from the Japanese KiK-net database, correlations between measured local amplifications and mappable proxies such as topographic slope and geology are explored. These are used subsequently to develop empirical models describing amplification as a direct function of slope, conditional upon geological period. These correlations also demonstrate the limitations of inferring 30-m shearwave velocity from slope and applying them directly into ground motion models. Instead, they illustrate the feasibility of deriving spectral acceleration amplification factors directly from sets of observed records, which are calibrated to parameters that can be mapped uniformly on a regional scale. The result is a geologically calibrated amplification model that can beProbabilistic assessment of seismic hazard and risk over a geographical region presents the modeler with challenges in the characterization of the site amplification that are not present in site-specific assessment. Using site-to-site residuals from a ground motion model fit to observations from the Japanese KiK-net database, correlations between measured local amplifications and mappable proxies such as topographic slope and geology are explored. These are used subsequently to develop empirical models describing amplification as a direct function of slope, conditional upon geological period. These correlations also demonstrate the limitations of inferring 30-m shearwave velocity from slope and applying them directly into ground motion models. Instead, they illustrate the feasibility of deriving spectral acceleration amplification factors directly from sets of observed records, which are calibrated to parameters that can be mapped uniformly on a regional scale. The result is a geologically calibrated amplification model that can be incorporated into national and regional seismic hazard and risk assessment, ensuring that the corresponding total aleatory variability reflects the predictive capability of the mapped site proxy.…
Author details: | Graeme WeatherillORCiD, Sreeram Reddy KothaORCiDGND, Fabrice CottonORCiDGND |
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DOI: | https://doi.org/10.1177/8755293019899956 |
ISSN: | 8755-2930 |
ISSN: | 1944-8201 |
Title of parent work (English): | Earthquake spectra : the professional journal of the Earthquake Engineering Research Institute |
Publisher: | Sage Publishing |
Place of publishing: | Thousand Oaks, CA |
Publication type: | Article |
Language: | English |
Date of first publication: | 2020/03/11 |
Publication year: | 2020 |
Release date: | 2023/06/09 |
Tag: | earthquake hazard analysis; ground motion; regional mapping; seismic risk; site effects |
Volume: | 36 |
Issue: | 1_SUPPL |
Number of pages: | 24 |
First page: | 274 |
Last Page: | 297 |
Funding institution: | Horizon 2020 "Seismology and Earthquake Engineering Research; Infrastructure Alliance for Europe (SERA)'' project; SIGMA2 consortium; (EDF); SIGMA2 consortium (CEA); SIGMA2 consortium (PGE); SIGMA2; consortium (SwissNuclear); SIGMA2 consortium (Areva); SIGMA2 consortium; (CEZ); SIGMA2 consortium (CRIEPI) |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
DDC classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
Peer review: | Referiert |