Publication Date:
2017-04-04
Description:
We merge volcanological, structural, and volcanic tremor
data to shed light on a fissure system opened on the
upper SE flank of Mt. Etna, Italy, in 1989. The system
propagates to about 6 km from the Southeast Crater
(SEC), and although it is formed by dry (non-eruptive)
NNW-SSE fissures, it was active throughout several
eruptive episodes after 1989, such as in 1991-1993 and
(at least in part) in 2001, 2004-2005, and 2006. Particularly,
we focus our attention on a paroxysmal eruptive
episode on 24 November 2006, which encompassed
different eruptive styles, such as lava fountaining and
effusion, and violent Strombolian explosions, involving
several eruptive vents on and near the SEC. This event
was documented by detailed field and aerial surveys
and remote video cameras. The characteristics of the
seismic radiation are analyzed considering: frequency
content, wavefield properties, and centroid location
of the volcanic tremor source. The synoptic analysis
of volcanic phenomena and volcanic tremor data
document that: i) an aborted intrusion of magma rose
to ~2000 m above sea level in the late evening of 24
November, along the NNW-SSE direction from below
the SEC towards the 1989 fracture system, ii) the fissures
opened in 1989 strongly affected, approximately
17 years after their formation, the modality of propagation
of the seismic energy radiation within the upper
volcanic edifice. Besides the role played by the 1989
system on the properties of seismic radiation in 2006,
the present study allows to postulate probable links between
contiguous fault systems in the upper SE flank
of Mt. Etna. Based on the structural framework on a
volcano-wide scale, our results do indeed sketch out a
hitherto unknown continuity of some faults affecting the
southeastern flank, which might also shed some light
onto the complex phenomenon of flank instability in the
eastern sector of the volcano.
Description:
Published
Description:
Puerto de la Cruz, Tenerife, Canary Islands, Spain
Description:
open
Keywords:
Fracture Reactivation
;
Volcanological data
;
Structural data
;
Seismic data
;
Mt. Etna
;
04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
Oral presentation
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