STRESS TENSOR COMPUTATIONS IN THE MOUNT ETNA AREA (SOUTHERN ITALY) AND TECTONIC IMPLICATIONS

Fault plane solutions of several tens of local-shear earthquakes recor ded in the Mount Etna volcanic area have been inverted for stress tens or parameters by Gephart and Forsyth's [J. geophys. Res. 89, 9305-9320 (1984)] method. The main findings can be summarized as follows: (i) s tress is homogeneous between 10 and 30 km of depth beneath western Etn a (longitude < 15 degrees E) with a low-dip N-S sigma(1) reconductible to the compressive tectonics of western Sicily and, more in general, to the Africa-Europe slow convergence; some stress heterogeneity is de tected at shallower depths in the same sector; (ii) the stress, style changes across the 15 degrees E meridian and becomes more complex bene ath eastern Etna, where no uniform stress model is able to explain the available fault plane solutions. In agreement with other geophysical and geological information available from the literature, the results of the present investigation can be explained by assuming that Western Etna belongs to the compressive domain of western Sicily, whereas Eas tern Etna is transitional towards the Calabrian Ard tensional domain. Copyright (C) 1996 Elsevier Science Ltd