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Re-thinking site amplification in regional seismic risk assessment

Graeme A. Weatherill, Sreeram Reddy Kotha and Fabrice Cotton
Re-thinking site amplification in regional seismic risk assessment (in GEM's 2018 global hazard and risk model, Marco Pagani (editor), Vitor Silva (editor), Kishor S. Jaiswal (editor) and Trevor Allen (editor))
Earthquake Spectra (October 2020) 36 (1, Suppl.): 274-297


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 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.

ISSN: 8755-2930
EISSN: 1944-8201
Serial Title: Earthquake Spectra
Serial Volume: 36
Serial Issue: 1, Suppl.
Title: Re-thinking site amplification in regional seismic risk assessment
Title: GEM's 2018 global hazard and risk model
Author(s): Weatherill, Graeme A.Reddy Kotha, SreeramCotton, Fabrice
Author(s): Pagani, Marcoeditor
Author(s): Silva, Vitoreditor
Author(s): Jaiswal, Kishor S.editor
Author(s): Allen, Trevoreditor
Affiliation: Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany
Affiliation: Global Earthquake Model (GEM) Foundation, International
Pages: 274-297
Published: 202010
Text Language: English
Publisher: Earthquake Engineering Research Institute, Berkeley, CA, United States
References: 22
Accession Number: 2021-013027
Categories: Seismology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. sketch maps
N30°00'00" - N45°00'00", E129°00'00" - E147°00'00"
Secondary Affiliation: University of Potsdam, DEU, Germany
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2021, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 202104
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