Task 3 (WG-T3): GMPEs calibration

(Giovanni Lanzano, Maria D’Amico, Chiara Felicetta)

The WG-T3 will develop a set of median GMPEs for Southern Italy, using the results of the previous tasks. In particular, three subsets of GMPEs will be retrieved:

• Empirical GMPEs based on the flatfile of recorded waveforms developed in Task 1;

• Physics-based GMPEs based on the flatfile of simulated waveforms developed in Task 2;

• Hybrid GMPEs based on the flatfile integrating the recorded and simulated data;

The results of the GMPEs calibration will be compared among them and with respect to other significant existing GMPEs. The goodness of fit will be evaluated on the basis of the total residuals, calculated as the difference between observations and predictions. The standard deviation of the total residuals of GMPEs has a strong influence on the results of PSHA. The sigma will be decomposed in the within-event and the between-event components in order to make a comparison between the standard deviations of empirical and synthetic data. These values will be finally compared to those evaluated for other world regions (Rodriguez-Marek et al. 2011; Al-Atik et al. 2010; Luzi et al. 2014).