In 1977 the working group «Catalogo dei Terremoti» (GCT) responsible for the «Progetto Finalizzato Geodinamica» (PFG) acquired the ENEL Catalogue of Italian earthquakes which, as the most complete and updated collection on domestic historical seismicity, lists over 20,000 events.

Twelve Operational Units, each having different territorial competence, have been working to reach the following goals:

1. a revision of the ENEL Catalogue of Italian earthquakes from 1000 to 1975 and its updating up to and including 1980;
2. the production of an atlas of the isoseismals of Italian earthquakes greater than intensity IX.

The above goals turned out to be too difficult to reach with the funds and the human resources available, and the catalogue was therefore updated with data supplied both by the national seismologic network and by local networks. Earthquakes previously listed incorrectly were also revised on the information that became available in the seismologic literature.

The coordinating Operational Unit was responsible for this effort, summarizing in the catalogue the information derived from the research aimed at studying those earthquakes having intensity ≥ IX MCS (Postpischl ed., 1985).

The GCT believes that a catalogue of the earthquakes where the information has been reduced to numerical values is not sufficient to answer the multiple questions related to the needs of territorial planning.

It hopes, therefore, to organize a Data Base capable of including all the information concerning the interaction between the earthquake and the territory needed to determine local seismicity (Bergamaschi et al. 1983).

In the catalogue only those earthquakes located within the area indicated in fig. 1 have been considered.