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Infrasonic evidences for branched conduit dynamics at Mt. Etna volcano, Italy
Author(s) -
Marchetti Emanuele,
Ripepe Maurizio,
Ulivieri Giacomo,
Caffo Salvatore,
Privitera Eugenio
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl040070
Subject(s) - impact crater , volcano , geology , magma , electrical conduit , infrasound , flux (metallurgy) , seismology , geophysics , strombolian eruption , amplitude , crater lake , petrology , astrobiology , physics , mechanical engineering , materials science , quantum mechanics , acoustics , engineering , metallurgy
On multi‐vents volcanoes changes in activity between different vents reflect a complex fluid‐dynamics of the shallow feeding systems and are often explained numerically and experimentally in terms of conduit branches and bifurcations. We present new geophysical constraints on the shallow feeding system of Etna volcano derived from array analysis of infrasound radiated from two distinct sources, one located in the SE crater and one in the Voragine or NE crater (VNE). These two sources alternated in their behavior, with the VNE crater system radiating low amplitude background infrasound interrupted by episodes of increased infrasound radiation from the SE crater. This switching behavior suggested a branched shallow feeding system strongly controlled by the gas/magma‐flux. Here, the VNE craters represented the preferential and most stable branch of degassing during stationary flux regime, while the SE crater branch activated in response to an increase in the magma/gas supply rate.