The Italian strong motion database: design, data input and web distribution

A new Italian strong-motion database was created during a joint project between the Istituto Nazionale di Geofisica e Vulcanologia (INGV, Italian Institute for Geophysics and Vulcanology) and the Dipartimento della Protezione Civile (DPC, Italian Civil Protection). The aim of the project was to collect, homogenize and distribute strong motion data acquired by different institutions, namely Ente Nazionale per l�Energia Elettrica (ENEL, Italian electricity company), Ente per le Nuove tecnologie, l�Energia e l�Ambiente (ENEA, Italian energy and environment organization) and the DPC with different purposes, such as permanent strong motion monitoring and temporary monitoring during seismic sequences or before permanent installation in Italy in the time span 1972-2004. The database contains 2182 three-component waveforms generated by 1004 earthquakes with a maximum moment magnitude of 6.9 (1980 Irpinia earthquake) and can be accessed on-line at the site http://itaca.mi.ingv.it. Here a wide range of search tools enables the user to interactively retrieve events, recording stations and waveforms with particular characteristics, whose parameters can be specified, as needed, through user friendly interfaces. A range of display options allows users to view data in different contexts, extract and download time series and spectral data. This article describes the database structure and the working steps which led to the completion of the project.