Volcanic tremor at Mount Etna (January 1984–March 1985): its relationship to the eruptive activity and modelling of the summit feeding system

Spectral analyses of volcanic tremor at Etna during January 1984–March 1985, have been performed and the relationship between tremor energy and observed volcanic phenomena have been examined. The highest energy levels have been observed during the paroxysmal phases of eruptions, whereas a gradual decrease was linked to the lowering of eruptive activity. Amplitude variations with time of some spectral frequency peaks (0.95, 1.20, 1.45, 1.65, 1.80 and 2.40 Hz) have been compared with volcanic activity at the summit craters, and on the basis of these results a new schematic diagram for the feeding system of the summit vents is proposed.