The New ShakeMap in Italy: Progress and Advances in the Last 10 Yr

Abstract

This work describes a procedure to configure U.S. Geological Survey (USGS)-ShakeMap for a given region. The procedure is applied to Italy to update and improve the ShakeMap service provided by Istituto Nazionale di Geofisica e Vulcanologia (INGV). The new configuration features (1) the adoption of recently developed ground-motion models (GMMs) and of an updated map of VS30 for the local site effects and (2) the adoption of the newly developed USGS-ShakeMap version 4 (v.4) software (see Data and Resources). We have used the same subdivision in tectonic regimes adopted for the GMMs for the new Italian seismic hazard model (MPS19, Meletti et al., 2017) and selected the most appropriate GMMs after applica- tion of a ranking procedure consisting of statistical tests. A cross- validation technique has been applied to test the goodness of the selected configuration and to compare the ShakeMaps obtained with the old (Michelini et al., 2008) and the new settings. Finally, the INGV ShakeMap workflow has been renovated to exploit the data and analysis chain implemented at INGV from real-time data streams acquisition to analyst revised waveforms including additional data (e.g., revised location, fault geometry) that may become available days after the event occurrence.