Publikationsdatum:
2017-04-04
Beschreibung:
Previous studies performed on Mt. Etna on short and
discontinuous time intervals indicate the North East Crater (NEC)
as the most active source of infrasound. The source mechanism of
NEC infrasound events was modeled as a double resonance. This
lead to infer the connection between the NEC and both the
southeast crater (SEC) and the eruptive fissure (EF), that opened at
the beginning of the 2008–2009 eruption. Nevertheless, there are
still several open questions that need to be addressed. For instance,
the steadiness of NEC event features should be studied, as well as
the orderliness of spectral changes of NEC events time-related to
eruptive activity of other vents. The investigation of such topics is
strongly enhanced by the possibility of analysing infrasound signals
during year-long time periods. With this aim about 40,000 infrasound
events, recorded at Mt. Etna from August 2007 to December
2009 were analysed by using spectral and location techniques. It
was noted in particular that the NEC events featured periods with
very steady waveforms and spectral characteristics lasting from
days to months with slow or sudden variations. The most important
eruptive episodes occurring at the SEC or the EF were accompanied
by significant spectral changes in NEC events. In light of such
systematic behaviour the connection between the NEC and the
SEC/EF plumbing systems was not considered temporary but rather
stable even during a relatively long time interval (2006–2009).
Moreover, study of NEC event spectral features and their changes
over multiple years supports the double resonance source model.
Such a model, together with the inferred connections between NEC
and SEC/EF feeding systems, implies that level fluctuations of a
magma column inside the NEC conduit correspond to magmastatic
pressure decrease/increase inside the main plumbing system. These
findings open up new and interesting possibilities for monitoring
magma pressure changes inside the Mt. Etna plumbing system.
Beschreibung:
Published
Beschreibung:
473–490
Beschreibung:
3V. Dinamiche e scenari eruttivi
Beschreibung:
JCR Journal
Beschreibung:
restricted
Schlagwort(e):
Infrasound
;
plumbing system geometry
;
Etna
;
04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
Repository-Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Materialart:
article
