Publication Date:
2017-04-04
Description:
In this paper we present the first data of temperature continuously recorded in two fumarole fields (designated
VOR and HOR) located in the summit area of Mount Etna volcano (Italy). The time series embraces two
distinct periods: (1) October 2007 to November 2009, during which an effusive eruption occurred from
May 2008 to July 2009, and (2) November 2011 to June 2012, characterized by the occurrence of strong paroxysms
(fire fountains and lava flow). The analysis of the temperature signal in both the time and frequency
domains, and its comparison with meteorological observations allowed us to separate the exogenous influences
from the effects of variations in the activity state of the volcano. The acquired data were weakly affected
by seasonal cycles of the air temperature and strongly affected by the rainfall. Optimization of site
conditions (i.e., sensor depth and soil permeability) markedly reduced meteorological disturbances. The distance
from the main degassing and/or eruptive fractures was crucial to maximizing the probability of the
technical survival of the monitoring apparatus, which was seriously affected by the emission of acidic
gases, tephra fallout, and lava flows. Apart from the exogenous influences, the most appreciable variation
was observed at VOR, where a huge increase in fumarole temperature was detected immediately after the
onset of the 2008–2009 eruption. Such an anomalous increase was attributed to the rapid ascent of magma
feeding the eruptive fracture. Another abrupt increase in temperature was recorded at HOR in March and
April 2012. During this period the frequency of paroxysm occurrence increased markedly, and this led us
to hypothesize that the thermal anomaly was due to the intrusion of a new batch of magma in the conduits
of the southeast crater. Medium- to long-term monitoring (weeks to months) of fumarole temperatures revealed
variations that were attributed to pressurization/depressurization phases of the shallow volcanic system,
which varied between the various monitored sectors of the volcano. Our observations suggest that
continuous monitoring of fumarole temperature can give useful information about the activity of Mount
Etna. Moreover, due to the complexity of its shallow plumbing system, we conclude that the monitoring systems
should be extended to cover the entire fumarole network of the summit area.
Description:
Published
Description:
12-20
Description:
1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
Description:
JCR Journal
Description:
restricted
Keywords:
Continuous monitoring
;
Mount Etna
;
Fumarole temperature
;
Meteorological parameters
;
Volcanic Degassing
;
04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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