GPS measurements in central-northern Italy for deterministic estimate of seismic hazard [Misure GPS nell'Italia centro settentrionale per la stima deterministica della pericolosità sismica]

The recognition of the Italian seismic zones most prone to next strong earthquakes could make economically feasible a gradual restoration of the building heritage in our country. Recent advancements of research suggest that achieving such information is not anymore impossible. The proposed approach is based on the study of the strain perturbation triggered by strong earthquakes. The hypothesis that such phenomenon can produce significant increase of earthquake probability in seismic zones undergoing particular conditions is suggested by the peculiar distribution of major historical earthquakes in some periAdriatic zones and by the quantification of post seismic visco-elastic relaxation in that area. The possibility of recognizing the propagation of the above phenomenon and its possible implications on earthquake probability in some zones can considerably be strengthened by the use of geodetic measurements. In this work, we describe the information that has been obtained by the analysis of the geodetic data acquired by a fairly dense network of 202 permanent GPS stations in Central and Northern Italy.