Modeling ground deformation associated with the destructive earthquakes occurring on Mt. Etna's southeastern flank in 1984

Abstract

Abstract. The Timpe Fault System is the source of very shallow but destructive earthquakes that affect several towns and villages on the eastern flank of Mt. Etna (Italy). In 1984, several seismic events, and specifically on October 25, caused one fatality, 12 injuries and produced serious damage in the Zafferana and Acireale territories. This seismicity was mainly related to the activity of the Fiandaca Fault, one of the structures belonging to the Timpe Fault System. We inverted ground deformation data collected by a geodimeter trilateration network set up in 1977 at a low altitude along the eastern side of the volcano in order to define the Timpe Fault System faulting mechanisms linked to the seismicity in 1984. We found that in the May 1980–October 1984 period, the Fiandaca Fault was affected by a strike slip and normal dip slip of about 27 and 23cm. This result is in fairly good accord with field observations of the co-seismic ground ruptures along the fault but it's notably large compared to displacements estimated by seismicity, then suggest ing that most of the slip over the fault plane was aseismic. The results once again confirm how seismicity and in particular ground ruptures represent a very high hazard to the several towns and villages situated along the Fiandaca Fault.

Tilt offset associated with local seismicity: the Mt. Etna January 9, 2001 seismic swarm.

“…Etna. In particular [19] concluded that only 30% of the total deformation of the Pernicana Fault is attributable to co-seismic displacements and [50] showed a seismic efficiency lower than 30% for the Fiandaca Fault (see Fig. 1 for their locations).…”