The flatfile contains the results of the shaking scenario, organized by points on a spatial grid. Each row represents a single site (grid node) and includes its coordinates, distance/site parameters, and ground motion predictions (median values and uncertainties) for various Intensity Measures (IM).

id: Unique numerical identifier of the point (or node) in the computational grid.

X_m: Planar Cartesian coordinate on the Easting axis (e.g., UTM projected system), expressed in meters.

Y_m: Planar Cartesian coordinate on the Northing axis, expressed in meters.

Latitude: Latitude of the site, expressed in decimal degrees (e.g., WGS84).

Longitude: Longitude of the site, expressed in decimal degrees.

Rrup: Rupture Distance, expressed in kilometers. It represents the minimum 3D distance between the site and the fault plane.

Vs30_Brunelli: Time-averaged shear-wave velocity in the top 30 meters (Vs30), expressed in m/s, extracted for that site from the map by Brunelli et al., 2025.

In the flatfile, predictive ground motion parameters are reported for multiple spectral periods (IM). For compactness, field names use an IM-identifying suffix, generically denoted as _[IM] (in the file header, it takes the form x[S][MMM], where x0_010 stands for T=0.010s, x0_500 for T=0.500s, and so on).


For each spectral period or parameter, the flatfile reports the following four fields:

Pred_[IM]: Median value predicted by the empirical model (Ground Motion Model, GMM by Lanzano et al., 2019) for the specific parameter, including site corrections based on Vs30.

PredMinSigma_[IM]: Predicted value minus one logarithmic standard deviation (corresponding to the 16th percentile of the distribution).

PredPlusSigma_[IM]: Predicted value plus one logarithmic standard deviation (corresponding to the 84th percentile of the distribution).

SigmaLN_[IM]: Total standard deviation of the model in natural logarithmic scale for the specific parameter. It represents the overall uncertainty associated with the median estimate.