Publication Date:
2017-04-04
Description:
On 5 April 2003 at 07:13 GMT (09:13 local time) a
violent vulcanian explosion occurred at Stromboli volcano.
At the time of the event an eruptive crisis was ongoing at the
volcano with a lava flow outpouring along the Sciara del
Fuoco flank. The seismic signals related to the event were
recorded by 8 permanent broadband stations and gives
information about the eruption kinematics. An ultra-longperiod
signal (period 〉 20 s), that we interpret as the effect
of the ground tilt on the broadband sensors, starts about 4 min
before and terminates about 1 min after the explosion. On the
basis of the radial pattern of tilt directions we conclude that
this signal is the effect of the deformation of the volcanic
edifice, due to the rapid rising of a batch of magma, its
ejection and the magma column readjustment. About 1 min
before the explosion we observe an high frequency signal
(period 〈 0.1 s) that we believe to be related to the
vesiculation of the rising batch of gas-rich magma. At
07:13:35 GMT a powerful very-long-period signal (period 2
20 s), marking the onset of the explosive fragmentation, is
recorded. This is confirmed by a blast wave following few
seconds later. The remaining seismic signal (more than
3 min), shows an higher frequency content being related
only to the fall of ballistic ejecta and to landslides along
Sciara del Fuoco.We propose the implementation of an early
warning system for the short-term forecast of such
explosions, based on the real-time automatic detection of
the tilt signals preceding such events.
Description:
Published
Description:
L08308
Description:
reserved
Keywords:
NONE
;
04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
;
04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
;
05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Format:
773734 bytes
Format:
application/pdf
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