title: Decrypting geophysical signals at Stromboli Volcano (Italy): Integration of seismic and Ground-Based InSAR displacement data.
abstract: We present the integration of seismic and Ground-Based Interferometric Synthetic Aperture Radar system (GBInSAR) displacement data at Stromboli Volcano. Ground deformation in the area of summit vents is positively correlated with both seismic tremor amplitude and cumulative amplitudes of very long period (VLP) signals associated with Strombolian explosions. Changes in VLP amplitudes precede by a few days the variations in ground deformation and seismic tremor. We propose a model where the arrival of fresh, gas-rich magma from depth enhances gas slug formation, promoting convection and gas transfer throughout the conduit system. At the shallowest portion of the conduit, an increase in volatile content causes a density decrease, expansion of the magmatic column and augmented degassing activity, which respectively induce inflation of the conduit, and increased tremor amplitudes. The temporal delay between increase of VLP and tremor amplitudes/conduit inflation can be interpreted in terms of the different timescales characterizing bulk gas transfer versus slug formation and ascent.
authors.affiliation: Department of Earth Sciences, Università degli Studi di Firenze Firenze, Italy ; Department of Earth Sciences, Università degli Studi di Pisa Pisa, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Di Traglia
authors.affiliation: Sezione di Pisa, Istituto Nazionale di Geofisica e Vulcanologia Pisa, Italy ; School of Geological Sciences, University College of Dublin Dublin, Ireland.
authors.forename: L
authors.initials: L
authors.lastname: Cauchie
authors.affiliation: Department of Earth Sciences, Università degli Studi di Firenze Firenze, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Casagli
authors.affiliation: Sezione di Pisa, Istituto Nazionale di Geofisica e Vulcanologia Pisa, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Saccorotti
keywords: GBInSAR monitoring; Strombolian explosions; very long period activity; volcanic tremor
references.citation: Science. 2007 Jul 13;317(5835):227-30
references.pmid: 17626881