A Bayesian update of ESHM20 ground-motion model for France
| Autor: | Kotha, S., Traversa, P. |
|---|---|
| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| DOI: | 10.57757/iugg23-0944 |
| Popis: | The ESHM20 ground-motion model (GMM) is developed using the pan-European Engineering Strong-Motion (ESM) dataset, and is applicable for earthquakes of 3 < Mw ≤ 7.4. This model accounts for regional variability of path and source effects via regionally adjustable anelastic attenuation and offset components, respectively, in its functional form. In low-moderate seismicity regions, such as France and Germany, events with lower Mws and paths of slower crustal attenuation could be of interest in seismic hazard assessments. For this purpose, we have performed a Bayesian update of the ESHM20 GMM using the French RESIF-RAP dataset containing ground-motion data from 2 < Mw ≤ 5.5 earthquakes. This procedure extends the GMM’s applicability to smaller earthquakes and apparently slower attenuating regions of France. The updated GMM, however, predicts larger median ground-motions with a larger aleatory variability – which together would aggravate the hazard estimates in France (compared to ESHM20). Here, we present our approach, outcome, and understanding of these systemic changes in GMM coefficients and predictions following the Bayesian update. Revision of attenuation regionalisation model of France and moment-magnitude estimates of French earthquakes are in process, and may help evaluate the procedure. We anticipate that such checks and refinements would become necessary before adapting the ESHM20 GMM in seismic hazard assessments of other low-moderate seismicity regions of pan-Europe. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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