SHALLOW STRUCTURE OF MT-VESUVIUS VOLCANO, ITALY, FROM SEISMIC ARRAY ANALYSIS

Data from a portable dense seismic array deployed on Mt. Vesuvius in M ay 1994, during a 2D seismic tomography experiment, are analyzed in th e present paper. The array consisted of two groups of short period geo phones, 4.5 hz natural frequency, formed by 16 and 25 vertical compone nts (plus two horizontal components), distributed along an are like sh ape along the summit crater. Stacks of later arrivals, interpreted as reflected phases, provide a significant constraint to a boundary layer located in the depth range 1.5 - 2.2 km beneath the summit crater wit h average velocity V = 1.8 - 2.2 km/s, interpreted as the top of the l imestone basement. The correlation methods applied on microtremor reco rds allowed to infer the shallow velocity structure, up to 400 m, bene ath the crater rim.