Investigation of the effect of using proxy-based Vs30 models for PSHA. The case of the M7.8, 2023 Pazarcik earthquake in Türkiye

抄録

In most large-scale seismic hazard and risk applications, local site conditions are inevitably taken into account through site models inferred from proxies, such as geology and terrain. In this study we examine the effect of applying proxy-based Vs30 models in PSHA analyses, focusing on the region affected by the M7.8 Pazarcik earthquake of February 2023 in Türkiye. To this end, we compare PSHA results obtained from two different proxy-based Vs30 models for the region with those obtained from a more precise site model developed from Vs30 data from AFAD-TADAS. The results indicate that for large-scale applications, and in exception of prominent near field conditions, the site proxies may provide a valuable tool in PSHA studies. In addition, a comparison of the PSHA results with the recorded ground motions allows for a quantitative estimate on how rare this earthquake event was.