You need JavaScript to view this

Shear-wave velocity models and seismic sources in Campanian volcanic areas: Vesuvius and Phlegraean fields

Abstract

This chapter summarizes a comparative study of shear-wave velocity models and seismic sources in the Campanian volcanic areas of Vesuvius and Phlegraean Fields. These velocity models were obtained through the nonlinear inversion of surface-wave tomography data, using as a priori constraints the relevant information available in the literature. Local group velocity data were obtained by means of the frequency-time analysis for the time period between 0.3 and 2 s and were combined with the group velocity data for the time period between 10 and 35 s from the regional events located in the Italian peninsula and bordering areas and two station phase velocity data corresponding to the time period between 25 and 100 s. In order to invert Rayleigh wave dispersion curves, we applied the nonlinear inversion method called hedgehog and retrieved average models for the first 30-35 km of the lithosphere, with the lower part of the upper mantle being kept fixed on the basis of existing regional models. A feature that is common to the two volcanic areas is a low shear velocity layer which is centered at the depth of about 10 km, while on the outside of the cone and along a path in the northeastern  More>>
Authors:
Guidarelli, M; Zille, A; Sarao, A; [1]  Natale, M; Nunziata, C; [2]  Panza, G F; [1]  Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)]
  1. Dipartimento di Scienze della Terra, Universita degli Studi di Trieste, Trieste (Italy)
  2. Dipartimento di Geofisica e Vulcanologia, Universita di Napoli 'Federico II', Napoli (Italy)
Publication Date:
Dec 15, 2006
Product Type:
Technical Report
Report Number:
IC-2006/145
Resource Relation:
Other Information: 50 refs, 10 figs, 5 tabs
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; EARTHQUAKES; ITALY; MAGMA; PHASE VELOCITY; RAYLEIGH WAVES; SEISMIC SOURCES; TOMOGRAPHY; VOLCANOES; WAVE PROPAGATION
OSTI ID:
20992773
Research Organizations:
Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
TRN: XA0703129016708
Availability:
Available from INIS in electronic form; Also available at: http://publications.ictp.it/preprints.html
Submitting Site:
INIS
Size:
23 pages
Announcement Date:
Mar 26, 2008

Citation Formats

Guidarelli, M, Zille, A, Sarao, A, Natale, M, Nunziata, C, Panza, G F, and Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)]. Shear-wave velocity models and seismic sources in Campanian volcanic areas: Vesuvius and Phlegraean fields. IAEA: N. p., 2006. Web.
Guidarelli, M, Zille, A, Sarao, A, Natale, M, Nunziata, C, Panza, G F, & Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)]. Shear-wave velocity models and seismic sources in Campanian volcanic areas: Vesuvius and Phlegraean fields. IAEA.
Guidarelli, M, Zille, A, Sarao, A, Natale, M, Nunziata, C, Panza, G F, and Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)]. 2006. "Shear-wave velocity models and seismic sources in Campanian volcanic areas: Vesuvius and Phlegraean fields." IAEA.
@misc{etde_20992773,
title = {Shear-wave velocity models and seismic sources in Campanian volcanic areas: Vesuvius and Phlegraean fields}
author = {Guidarelli, M, Zille, A, Sarao, A, Natale, M, Nunziata, C, Panza, G F, and Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)]}
abstractNote = {This chapter summarizes a comparative study of shear-wave velocity models and seismic sources in the Campanian volcanic areas of Vesuvius and Phlegraean Fields. These velocity models were obtained through the nonlinear inversion of surface-wave tomography data, using as a priori constraints the relevant information available in the literature. Local group velocity data were obtained by means of the frequency-time analysis for the time period between 0.3 and 2 s and were combined with the group velocity data for the time period between 10 and 35 s from the regional events located in the Italian peninsula and bordering areas and two station phase velocity data corresponding to the time period between 25 and 100 s. In order to invert Rayleigh wave dispersion curves, we applied the nonlinear inversion method called hedgehog and retrieved average models for the first 30-35 km of the lithosphere, with the lower part of the upper mantle being kept fixed on the basis of existing regional models. A feature that is common to the two volcanic areas is a low shear velocity layer which is centered at the depth of about 10 km, while on the outside of the cone and along a path in the northeastern part of the Vesuvius area this layer is absent. This low velocity can be associated with the presence of partial melting and, therefore, may represent a quite diffused crustal magma reservoir which is fed by a deeper one that is regional in character and located in the uppermost mantle. The study of seismic source in terms of the moment tensor is suitable for an investigation of physical processes within a volcano; indeed, its components, double couple, compensated linear vector dipole, and volumetric, can be related to the movements of magma and fluids within the volcanic system. Although for many recent earthquake events the percentage of double couple component is high, our results also show the presence of significant non-double couple components in both volcanic areas. (author)}
place = {IAEA}
year = {2006}
month = {Dec}
}