ITACAs2s flatfile: table of site response spectral curves 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 in two ways (Lanzano et al. 2020): i) δS2S800: with respect to generic rock condition of ITA18-SA, i.e., VS,30=800m/s; ii)δS2Ss: with respect to the corresponding site condition of the recording station, given by the VS,30 value. The dataset used for this analysis is the ITACAext, composed of the data and metadata included in ITACA up to 2020 December 31st, 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 computation of the site-to-site component is performed by applying the random-effect model (Bates et al., 2015), while the associated variability is evaluated by standard deviation of the aleatory residuals at the site.The flat-file includes 1,922 stations and can be exploited to have an overview of the amplifications and peculiar features of the Italian recording stations.