INSIGHTS INTO ERUPTION DYNAMICS AND SHALLOW PLUMBING SYSTEM OF MT. ETNA BY INFRASOUND AND SEISMIC SIGNALS

The success in eruption forecasting needs the knowledge of the eruptive processes and the plumbing system of the volcano. Indeed, the eruptive styles are controlled by the interplay between magma dynamics and the plumbing system. In multi-vent volcanoes, such as Mt. Etna, where volcanic activity can rapidly vary over time and be simultaneously at the different craters, the shallow plumbing system is quite complex. For forecasting purposes, volcano monitoring measures many geophysical parameters and interprets sub-aerial volcanic phenomena. Lots of volcanic processes occur at or near the boundary between the earth and the atmosphere, thus, beside seismic signal, acoustic waves mainly in the range of infrasound are generated. In particular, infrasound activity is usually evidence of open conduit conditions and its quantification can provide information on explosive phenomena and source mechanism. A more comprehensive knowledge of the source mechanism, as well as of the source depth into the conduit, can be achieved by exploring seismo-acoustic sources, exciting mechanical waves both in the volcano edifice and in the atmosphere. The aim of the thesis is to look closely at the eruption dynamics at Mt. Etna, with a focus on explosive activity, and at the shallow plumbing system by means of analysis of infrasound and seismo-acoustic signals.