GNGTS 2022 - Atti del 40° Convegno Nazionale

328 GNGTS 2022 Sessione 2.2 The method shows the ability to characterize the heterogeneity of the ground motion of earthquakes even considering the effects of finite fault and site response in complex conditions (2D and 3D). For instance, our study finds that the empirical observations of path-specific residuals correlate well with expected propagation effects in Central Apennine region, which reflect the underlying geomorphological structure and the evidences on the rheology and tectonic stability of portion of earth crust (i.e., amplification of ground motion corresponds to lower attenuation). Local effects due to shallow geology or basin effects at long-periods are also captured by the site corrections and consequently by the final shaking maps. The application potential of this promising methodology is mainly intended in the field of site-specific hazard and risk assessments with the aim to: - assessing the shaking pattern of events in near real-time; - post-processing past and historical earthquakes; - designing an intermediate-level technique for scenarios simulation, useful until the results of numerical models are made available; - preliminarily judge the reasonability of numerically simulated scenarios; - reproducing scenarios of potential future events. Ongoing developments include the adoption of an advanced approach for geospatial modeling of the empirical site functions at those sites that lack direct observations to get more accurate site maps, as well as the integration of the empirical effects of rupture directivity in the predictions. The approach proposed here is very promising in densely sampled areas because the estimation of repeatable site, propagation and source terms is reliable. In areas where records are limited, the development of hybrid ground motion models, based on the integration of observed and simulated data, could be a viable alternative. Acknowledgments . This study has also benefited from funding provided by the agreement B1, DPC-INGV 2019–2021 between INGV and the Italian Dipartimento della Protezione Civile (DPC). References Abrahamson, N. A., Kuehn, N., Walling, M., and Landwehr, N. (2019). Probabilistic Seismic Hazard Analysis in California Using Nonergodic Ground-Motion Models. Bull. Seismol. Soc. Am., 109(4), 1235-1249. https://doi. org/10.1785/0120190030. Anderson, J. G., and Brune, J. N. (1999). Probabilistic Seismic Hazard Analysis without the Ergodic Assumption. Seismol. Res. Lett., 70(1), 19-28. https://doi.org/10.1785/gssrl.70.1.19. Lanzano, G., Sgobba, S., Caramenti, L., Menafoglio, A. (2021). Ground-Motion Model for Crustal Events in Italy by Applying the Multisource Geographically Weighted Regression (MS-GWR) Method . Bulletin of the Seismological Society of America; 111 (6): 3297–3313. doi: https://doi.org/10.1785/0120210044 Landwehr, N., Kuehn, N. M., Scheffer, T., and Abrahamson, N., 2016. A Non Ergodic Ground-Motion Model for California with Spatially Varying Coefficients . Bull. Seism. Soc. Am. 106(6), 2574-2583. https://doi. org/10.1785/0120160118. Kuehn, N. M., Abrahamson, N. A., and Walling, M. A., 2019. Incorporating Nonergodic Path Effects into the NGA-West2 Ground-Motion Prediction Equations. Bull. Seism. Soc. Am. 109(2), 575-585. https://doi. org/10.1785/0120180260. Parker, G. A., Stewart, J. P., Boore, D. M., Atkinson, G. M., and Hassani, B. (2022). NGA-subduction global ground motion models with regional adjustment factors. Earthq. Spectra 38(1), doi:10.1177/87552930211034889. Rodriguez-Marek, A., F. Cotton, N. A. Abrahamson, S. Akkar, L. Al Atik, B. Edwards, G. A. Montalva, and H. Dawood; 2013: A model for single-station standard deviation using data from various tectonic regions , Bull. Seismol. Soc. Am. 103, 3149–3163 Sgobba S., Lanzano G., Pacor F., Puglia R., D’Amico M., Felicetta C., Luzi L. (2019) Spatial Correlation Model of Systematic Site and Path Effects for Ground‐Motion Fields in Northern Italy. Bulletin of the Seismological Society of America. Vol. 109, No. 4, pp. 1419–1434 Sgobba, S, Lanzano, G, Pacor, F. Empirical nonergodic shaking scenarios based on spatial correlation models: An application to central Italy. Earthquake Engng Struct Dyn. 2021; 50: 60– 80. https://doi.org/10.1002/eqe.3362 Worden, C. B., Thompson, E. M., Baker, J. W., Bradley, B. A., Luco, N., and Wald, D. J. (2018). Spatial and Spectral Interpolation of Ground- Motion Intensity Measure Observations. Bull. Seism. Soc. Am., 108 (2), 866-875. https:// doi.org/10.1785/0120170201.