Investigation on Mt. Etna dynamics by seismic and acoustic signals (August 2007-December 2010)
type: CreativeWork
description: In order to shed light on the dynamics of the plumbing system, and define the source-mechanism of acoustic events at Mt. Etna, infrasound signals-continuously recorded by Istituto Nazionale di Geofisica and Vulcanologia- were analyzed in this thesis, jointly with some seismic signals. In particular, we focused on the period comprised between August 2007 and December 2010, during which a wide spectrum of eruptive activity occurred. Until the activation of Bocca Nuova (BN), on August 2010, the three main vents radiating infrasound were North East Crater (NEC), South East Crater (SEC), and the Eruptive Fissure of the 2008-2009 eruption (EF). Location and spectral analyses carried out on the infrasound signals, revealed the numerical dominance and the steadiness of NEC events, radiating almost continuously acoustic energy, oppositely to SEC and EF. Furthermore, NEC events most relevant changes (spectral and amplitude variation) occurred systematically after the renewal of activity at SEC or at the EF. This evidence led us to infer the existence of a persistent link among their feeding system, and confirm the presence of a double resonance model for NEC events. Successively, events from EF were gathered and analyzed in detail through high precision location methods, allowing to define the cyclic activation of an highest altitude vent along the fissure, likely corresponding to the arrival of new batch of magma, rich in volatiles. During 2010, instead, Mt. Etna eruptive style was different, being characterized by a total number of roughly 35 minor ash emissions from SEC, BN and NEC. Three main episodes are here analyzed, by studying the morphological and compositional features of the sampled ash and the seismic and acoustic signals radiated during those events. Different conditions were deduced for the craters. In particular, for SEC and BN the presence of material plugging the upper conduit was inferred, while data shows that NEC was characterized by open conduit conditio…
abstract: In order to shed light on the dynamics of the plumbing system, and define the source-mechanism of acoustic events at Mt. Etna, infrasound signals-continuously recorded by Istituto Nazionale di Geofisica and Vulcanologia- were analyzed in this thesis, jointly with some seismic signals. In particular, we focused on the period comprised between August 2007 and December 2010, during which a wide spectrum of eruptive activity occurred. Until the activation of Bocca Nuova (BN), on August 2010, the three main vents radiating infrasound were North East Crater (NEC), South East Crater (SEC), and the Eruptive Fissure of the 2008-2009 eruption (EF). Location and spectral analyses carried out on the infrasound signals, revealed the numerical dominance and the steadiness of NEC events, radiating almost continuously acoustic energy, oppositely to SEC and EF. Furthermore, NEC events most relevant changes (spectral and amplitude variation) occurred systematically after the renewal of activity at SEC or at the EF. This evidence led us to infer the existence of a persistent link among their feeding system, and confirm the presence of a double resonance model for NEC events. Successively, events from EF were gathered and analyzed in detail through high precision location methods, allowing to define the cyclic activation of an highest altitude vent along the fissure, likely corresponding to the arrival of new batch of magma, rich in volatiles. During 2010, instead, Mt. Etna eruptive style was different, being characterized by a total number of roughly 35 minor ash emissions from SEC, BN and NEC. Three main episodes are here analyzed, by studying the morphological and compositional features of the sampled ash and the seismic and acoustic signals radiated during those events. Different conditions were deduced for the craters. In particular, for SEC and BN the presence of material plugging the upper conduit was inferred, while data shows that NEC was characterized by open conduit conditio…
author: SPINA, LAURA
language: eng
keywords: infrasound, plumbing system, resonance, Etna
date published: 2013-12-05
date modified: 2026-07-24T01:35:03Z
provider: Università degli Studi di Catania
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Università degli studi di Catania

PropertyValue
property ID: Handle
value: https://hdl.handle.net/20.500.11769/587915