An evaluation of the applicability of current ground-motion models to the South and Central American subduction zones

Abstract

The applicability of existing ground‐motion prediction equations (GMPEs) for subduction‐zone earthquakes is an important issue to address in the assessment of the seismic hazard affecting the Peru–Chile and Central American regions. Few predictive equations exist that are derived from local data, and these do not generally meet the quality criteria required for use in modern seismic hazard analyses. This paper investigates the applicability of a set of global and regional subduction ground‐motion models to the Peru–Chile and Central American subduction zones, distinguishing between interface and intraslab events, in light of recently compiled ground‐motion data from these regions. Strong‐motion recordings and associated metadata compiled by Arango, Strasser, Bommer, Boroschek, et al. (2011) and Arango, Strasser, Bommer, Hernandez, et al. (2011) have been used to assess the performance of the candidate equations following the maximum‐likelihood approach of Scherbaum et al. (2004) and its extension to normalized intraevent and interevent residual distributions developed by Stafford et al. (2008). The results of this study are discussed in terms of the transportability of GMPEs for subduction‐zone environments from one region to another, with a view to providing guidance for developing ground‐motion logic trees for seismic hazard analysis in these regions.