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Seismological insight into the kinematics of the 5 April 2003 vulcanian explosion at Stromboli volcano (southern Italy)
Author(s) -
D'Auria Luca,
Giudicepietro Flora,
Martini Marcello,
Peluso Rosario
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl026018
Subject(s) - seismology , volcano , geology , magma , impact crater , lava , ejecta , vulcanian eruption , explosive material , explosive eruption , physics , geography , astrobiology , archaeology , quantum mechanics , supernova
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‐long‐period 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.