Seismic and petrological data are analyzed with reference to the eruptive phenomena at Mt. Etna from 1974–1984. Seismological data show that most earthquakes occur within the upper 16 km of the crust and very few below 30 km. Focal solutions for events at depth between 7 and 16 km show evidence of both normal and thrust faults, due to an unstable stress field, whereas at shallower levels only normal mechanisms are observed. In most cases, enhanced seismic activity preceded the beginning of adventive eruptions, but neither upward migration nor clear concentration of epicenters near the eruptive area (except for the shallowest events; h < 1 km) was observed.Petrological analyses of the products from the various eruptions show no regular variations and suggest that slightly different magmas rose up through a complex system of fractures, having possibly resided at various levels. The results of this study suggest that tectonics strongly control the eruptive activity at Mt. Etna, allowing magmas to be stored at depth and providing ways to the surface for them.
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- Feeding Mechanism of Eruptive Activity at Mt. Etna Based on Seismological and Petrological Data
- Vieweg+Teubner Verlag