Location of the source and shallow velocity model deduced from the explosion quakes recorded by two seismic antennas at Stromboli volcano

The seismic wavefield associated to the ongoing eruptive activity at Stromb oli volcano (Italy) is investigated using data from two small-aperture, sho rt-period seismic arrays deployed on the northern and western flanks, locat ed at about 1.7 km from the active craters. Two distinct approaches are use d to analyze the recorded signals: 1) the zero-lag cross-correlation method is used to analyze the explosion q uakes data, to estimate slowness and backazimuth as a function of lapse tim e; 2) multiple filter technique and phase matched filtering are used to estima te Rayleigh wave dispersion, to obtain a shallow velocity model of the two sites. Estimates of slowness vectors at the two different array sites show a prima ry (volcanic) source located at shallow depth beneath the crater region. Se condary sources associated with path effects are located in close proximity of the sector graben of Sciara del Fuoco and of the old parasitic cone of Timpone del Fuoco. The shallow velocity structure derived for the western, flank depicts striking resemblance with that previously inferred for the no rthern flank of the volcano. (C) 2000 Elsevier Science Ltd. AII rights rese rved.