E. Del Pezzo

TL;DR: A new strategy for reliable automatic classification of local seismic signals and volcano-tectonic earthquakes (vt) is presented, based on a supervised neural network in which a new approach for feature extraction from short period seismic signals is applied.

TL;DR: In this paper, passive high-resolution attenuation tomography is used to image the geological structure in the first upper 4 km of the shallow crust beneath the Campi Flegrei caldera, southern Italy.

TL;DR: In this article, Coda-Q estimates for the Granada Basin (Southern Spain) are obtained by analyzing earthquakes occurring within or close to the borders of this area, and the data set is composed of 54 earthquakes with local magnitudes ranging between 2.2 and 4.0.

TL;DR: In this paper, the authors investigated the intrinsic dissipation and scattering properties of the lithosphere under the Southern Apennines, Italy and applied the MLTW analysis in the hypothesis of velocity and scattering coefficient constant with depth.

Abstract: We analysed short-period seismograms from about 250 very local events recorded by a network of high dynamic range short-period seismic stations deployed on Mt Vesuvius to estimate the site-corrected short-period seismic attenuation. We calculated QC− 1, the inverse of the quality factor for coda waves, for short lapse times (12 s), and QP− 1 and QS− 1, the inverse of the direct body wave quality factors for P and S waves follow- ing shallow ray paths. We used the single scattering assumption to fit the amplitude envelopes of the coda at different frequency bands, obtaining a QC− 1 slowly varying with frequency, similar to values measured for other volcanoes at the same lapse time. Site-corrected QP− 1 and QS− 1 were estimated using the frequency decay method for both P and S waves in two frequency bands, 1–6 Hz and 15–24 Hz. Results show that QP− 1 is 0.028 in both frequency bands, and QS− 1 is 0.015 and 0.017 at low and high frequencies respectively, almost independent of the frequency, and that the value of QP− 1 is about twice that of QS− 1, as measured worldwide. A check was made by measuring the broadening of the first P-wave pulse with station–source distance, finding QP− 1=0.024. Using the independent estimates of QC− 1 and QS− 1, we separated the intrinsic from the scattering quality factor at Mt Vesuvius, obtaining a high scattering and a low intrinsi c Q− 1, as already observed for other volcanoes. This result confirms the hypothesis of the predominant role of the scattering phenomena with respect to the intrinsic dissipation in the seismogram formation for volcanic earthquakes.