M. Castellano et al., RECENT DEEP EARTHQUAKE OCCURRENCE AT MT. ETNA (SICILY, ITALY), Physics of the earth and planetary interiors, 102(3-4), 1997, pp. 277-289
The seismic activity of Mt. Etna from April 1988 until the December 19
91 eruption was monitored by means of permanent and temporary seismic
networks. Volcanic activity that occurred during this period (tremor i
ncrease with lava fountains at the Summit Craters and eruptions) was p
receded and accompanied by the occurrence of deep (Z greater than or e
qual to 15km) seismicity. This deep seismic activity, occurring a few
days up to some weeks before the volcanic phases, was characterized by
typical mainshock-aftershocks sequences. Focal mechanisms of the more
energetic events which preceded the eruptions show that the compressi
on axis was nearly north-south, parallel to the direction of the compr
essive stress field acting in the area at regional scale. Both the obs
ervation of deep seismicity occurrence also before or during previous
eruptions and the role played by tectonics as controller of the magma
uprise suggest the hypothesis of a relation between the seismic energy
released in the volcanic basement and the recharge mechanisms of the
volcanic system, In this hypothesis the deep seismicity located in the
Etnean area could be considered as a possible 'forerunner' of volcani
c activity. (C) 1997 Elsevier Science B.V.