Correlation between eruptions of Mount Etna, Sicily, and regional earthquakes as seen in historical records from a.d. 1582

Catalogues from 1582 to the present of Etnean eruptions and earthquakes from various structural zones of southern Italy have been statistically compared using non-stationary Poisson statistics in order to search for correlative seismic and eruptive activity. A significant relationship exists between flank eruptions and earthquakes in the zone immediately surrounding the volcano. Also, crater eruptions are found to occur before flank eruptions which are not preceded by earthquakes. They do not, however, appear to be correlated with earthquakes. Earthquakes of different structural zones appear to be largely independent of each other. The results suggest two mechanisms for the flank eruptions of Etna. Those that are preceded by crater eruptions are presumed to be caused by magma pressure within Etna's storage reservoir. Whereas those preceded by earthquakes are thought to be due to fracturing of the flank by earthquakes caused by tensile forces associated with the east—west extension of eastern Sicily. The existence of earthquake-related volcanism is consistent with models which attribute Etna's existence to the extensional tectonism and lithospheric faulting in eastern Sicily.