Receiver Functions Analysis and Regional Tomography at StromboliVolcano (Italy)

This study focuses on constraining the crust and upper mantle discontinuities at Stromboli volcano by considering both receiver function (RF) analysis on teleseismic body waveforms and regional tomography. The RF technique utilizes the waveforms of Ps conversions from velocity discontinuities to model variations in Vs beneath a seismic station (e.g. Ammon et al., 1990). The method is sensitive to velocity discontinuities, but it can only detect the velocity-depth product, and not the absolute velocity. Therefore, we use the regional tomographic results as an independent constraint on absolute velocity. In order to improve the velocity model beneath the volcano we reviewed the most recent classical local earthquake tomographies available for the thyrrenian region. Here we show a new lithospheric seismic tomography performed in the northeastern Sicily and southern Calabria, including the Aeolian Archipelago and Stromboli volcano area. The dataset, consisting of P and S arrival times from a thousand of earthquakes located in the studied area between 1994-2003, was inverted by using the standard tomography SimulPS and the double-difference algorithm of TomoDD (Zhang and Thurber, 2003) for simultaneous computation of hypocenter parameters and Vp and Vs three dimensional distributions. For RF analysis the seismograms from about 100 teleseismic earthquakes (M greater than 6.0), recorded between 2004 and 2006 at 13 broad-band seismic stations deployed by the INGV, have been considered to compute the receiver function by the Multi-Taper Spectral Correlation (MTSC) technique (Park and Levin, 2000). One key advantage of this method is its resistance to noise, which recommends its use in environments such as ocean sea islands with high noise levels in the seismic bands.