Seismoacoustic investigations of paroxysmal activity at Mt. Etna volcano: New insights into the 16 November 2006 eruption

Abstract

[1] On 16 November 2006, a 1 day long paroxysmal eruption occurred at the summit craters of Mt. Etna volcano. A multiparametric approach, consisting of analyzing infrasonic, seismic, and video camera recordings, was carried out to follow its evolution. Volcanological and geophysical observations identified three eruptive phases. In the first phase, infrasonic and seismic characteristics reflected the highly explosive nature of the activity. Waveform characterization of infrasound events confirmed the activity of the several explosive vents at the summit of Southeast Crater (SEC). During the second phase, results highlighted the decoupling between seismic and infrasonic sources, which was due to the decrease in explosive activity and the reactivation of effusive vents located south of Bocca Nuova and on the saddle between Bocca Nuova and SEC. The third phase was the most intense and was characterized by various volcanic phenomena (pyroclastic flows, jets of dark ash, and white steam). The very high radiated infrasonic energy, together with infrasound event features, led us to infer a gas enrichment of the shallow magma column, preceding by a few minutes and likely related to the pyroclastic flows in the SEC area. After the eruption at SEC, variations in infrasound events related to the activity of Northeast Crater (NEC) were found. The observed spectral changes and the source mechanism modeling of the NEC infrasound events suggest the existence of a link in the plumbing system feeding the two craters.

Seismic and infrasound signals at Mt. Etna: Modeling the North-East crater conduit and its relation with the 2008–2009 eruption feeding system

“…Sahetapy-Engel et al, 2008;Pistolesi et al, 2011;Sciotto et al, 2011). In particular, it has proved to be very useful in conjunction with seismic signal analysis (Arrowsmith et al, 2010).…”

“…Etna (e.g. Di Grazia et al, 2009;Sciotto et al, 2011). Currently, Etna is characterized by four active summit craters: Voragine, Bocca Nuova, South-East crater and North-East crater (hereafter referred to as VOR, BN, SEC and NEC, respectively; Fig.…”

Site effect determination using seismic noise from Tungurahua volcano (Ecuador): implications for seismo-acoustic analysis

“…This is potentially important for seismo-acoustic studies of volcanic explosions, in which the differences in ratios of acoustic and seismic energies are explained as physical changes related to the source conditions (Hagerty et al 2000;Rowe et al 2000;Johnson et al 2003). Johnson & Aster (2005), Sciotto et al (2011) and Andronico et al (2013) have all noted that the computation of the seismic energy needs to take into account the site effects, which should improve the accuracy of the estimation of the volcanic acoustic seismic ratio (VASR). Additionally, it is frequently observed in the case of volcanic explosions that the air waves are coupled into the seismic record (e.g.…”

MeMoVolc consensual document: a review of cross-disciplinary approaches to characterizing small explosive magmatic eruptions

“…Seismic data sets are available, for example, for gaspistoning events, puffing, fountains and Strombolian eruptions at mafic systems (e.g. Goldstein and Chouet 1994;Ripepe et al 1996;Sciotto et al 2011;Ripepe and Braun 1994), as well as for events that generate somewhat larger plumes during silicic eruptions, as at Santiaguito, Soufriere Hills and Redoubt. Associated pressure impulses (typically recorded by infrasound and barometers) have long been recorded for such energetic events, famous examples including the pressure response to the 1883 eruption of Krakatoa and the 1967 caldera-forming eruption of Fernandina (Simkin and Howard 1970).…”