Publication Date:
2017-04-04
Description:
On 13 May 2008 an eruptive fissure opened on Mount Etna's eastern flank feeding both explosive activity and
lava effusion from multiple vents for about 14 months. During the investigated May-September 2008 eruptive
period, infrasound recordings from a 4 station-sparse network allowed tracking of the explosive activity
in terms of location and dynamics. In order to focus on activity from the eruptive fissure, the infrasonic events
generated by the summit craters were selected by using both spectral features and time delays between pairs
of stations and excluded from our analysis. Then, to accurately locate events from the fissure, we used a composite
method, based on the semblance and brightness functions. This enabled the study of the co-existence
of more than one infrasound source and/or its migration along the eruptive fissure. Hence, results permitted
us to discriminate the number of active vents and their location along the fissure even when, due to poor
weather conditions, it was not possible to access the vents or carry out direct observations. The eruptive activity
was characterised by variations in the number of active vents according to the overall intensity of the
eruptive event. Variability of the infrasound waveforms highlighted either that distinct vents produced signals
with different waveforms, or that single vents generated different events during distinct periods of
time, or finally both the previous phenomena. We applied the strombolian bubble vibration model to
model waveform differences and attributed the signal variations to bubble radius changes.
Description:
Published
Description:
1-11
Description:
1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
Description:
JCR Journal
Description:
reserved
Keywords:
Etna
;
Infrasound
;
Infrasonic source location
;
explosive activity
;
04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
