Characterization of seismicity at Mt. Etna volcano (Italy) by inter-event time distribution

摘要: Abstract The space–time inter-event time (IET) distributions of earthquakes occurring from 1988 to 2011 at Mt. Etna are analysed in order identify the periodicity or stationary behaviour seismicity, and correlate it with volcano-tectonic features region. comparison between IET those obtained both for Sicily Italy, shows that IETs a larger scale well-modelled by gamma distribution, whereas local they characterised bimodal curve, which two peaks related to: (i) contribution seismic swarms very short times, (ii) background regional seismicity. analysis is an important tool investigate seismicity different crustal levels region, distinguishing sectors influenced volcano dynamics tectonics. Indeed, spatial variation distributions, analysing sectors, shallower than 5 km almost entirely times mainly confined summit area. For deeper eastern flank volcano, as well Sicily, independent events suggest areas same extensional regime. By contrast, western north-western marked peaks, indicating compressional stress acting areas.