ITACAs2s flatfile 2.0: table of empirical amplification functions of the Italian recording stations

The ITACAs2s flat-file is a parametric table containing the repeatable site terms δS2S (Al-Atik et al., 2010) and the associated variabilities, evaluated with respect to the ITA18 ground-motion model (Lanzano et al., 2019) for acceleration spectral ordinates (SA, 5% damping). These terms quantify the systematic deviations between observed ground-motion and predictions at a site. They are estimated with respect to generic rock condition of ITA18-SA, i.e., VS,30=800m/s. The dataset used for this analysis is the ITACAext, composed of the data and metadata included in ITACA, integrated with some velocimetric waveforms. The adopted ITA18 model is valid for the median of the horizontal component in the moment-magnitude range Mw [3.5-7.5] and rupture distance interval R [0-200km]. The flat-file includes 916 stations and can be exploited to have an overview of the amplifications and peculiar features of the Italian recording stations. Compared to version 1.0, the dataset of recordings used for the calculation of the amplification function was extended to 31 December 2022. In addition, the amplification functions for the ordinates of the Fourier amplitude spectrum, in the frequency range f=0.1-30Hz, and the empirical amplification factors, according to the Guidelines for Italian Seismic Microzonation (SM-WG, 2008) for PGA, PGV and three period intervals of the ordinates of the acceleration response spectra SA (5% damping): 0.1-0.5s; 0.4-0.8s; 0.7-1.1s, are also computed.