Macroseismic study of the Gulf of Patti earthquake in the geostructural frame of north-eastern Sicily

A macroscismic study of the Gulf of Patti earthquake (15th April 1978, Sicily) is prcesented with the aim of examining closely the elements of comparison with the macroseismic field observed in the geological and structural context of the area involved. The seismic event felt for a radius of 150 km affectcd almost the whole of Sicily, and Calabria as far as the Sila plateau. From the analysis of the data gathered, the isoseismals, the focal depth (h = 25 km) and the attenuation coefficient values along the principal trends found were charactcrlsed. The seismicity of the area is likewise characterised, more reliably for thc last 270 years, by a greater concentration of activity between the Tindari- Giardini line and the Naso area, along a belt which develops in a NNW-SSE direction. The frequency-magnitude equation can be established as well as the strain release curve relative to the last 500 years. Having found that the mesoseismic area of the earthquake has a preferential development in a NNW-SSE direction, it is believed that the structure responsible for the event develops in the same direction and thus concords with the seismo-structural context of the region.