Changing in crust mechanical behaviour due to raising magma: A fracturing model of SE flank of Mt. Etna (Sicily)

Associated with the remarkable flank eruption which started in late October 2002, a series of earthquakes occurred on the lower eastern flank of Mt. Etna. The MD = 4.4 Bongiardo–S.Venerina earthquake (at 10:02 am GMT, 29th October) affected a large NNW–SSE area severely damaging nearby villages. The faulting model proposed in this paper seeks to justify the two causes of the fracturing process as well as its spatiotemporal development. For this purpose, a preliminary analysis of the morphotectonic framework, and the detected fractures linked to October 2002 earthquakes has been carried out. We will therefore consider the seismic activity which affected the volcano in 2001 and 2002. Additionally we will review previous scientific studies of seismic tomography and macroseismic data. In particular the fracturing mechanisms appear to be linked to the volcanic area uplift, as a consequence of rising magma. The consequent change in the rheology beneath this sector of the volcano explains the differing reaction of the crust at different levels.