Space-time evolution of seismic activity at Mount Etna during 1974-1982

This paper summarizes all results obtained from temporary and fixed seismic arrays installed on Mount Etna in the period 1974-1982. A set of velocity models derived from travel-time inversion of local microearthquakes arrival times and deep seismic sounding data have been analyzed, and used for routine locations. A few fault plane solutions obtained from data of a temporary seismic array have shown complexities in the faulting process, with a simultaneous presence of both normal and thrust fault motions, but located at different depth. It is noteworthy that this stress field agrees with previous models inferred from structural and tectonic studies. The present work suggests the need of extending seismic studies on Mount Etna, for their great importance in monitoring and predicting the volcanic activity, as in the case of flank eruptions occurred during 1974, 1979 and 1981, and also for a better understanding of the physical mechanisms of eruptions of this volcano.