Publication Date:
2017-04-04
Description:
The 2001 eruption represents one of the most studied events both from volcanological and geophysical point
of view on Mt. Etna. This eruption was a crucial event in the recent dynamics of the volcano, marking the
passage from a period (March 1993–June 2001) of moderate stability with slow, continuous flank sliding and
contemporaneous summit eruptions, to a period (July 2001 to present) of dramatically increased flank
deformations and flank eruptions. We show new GPS data and high precision relocation of seismicity in
order to demonstrate the role of the 2001 intrusive phase in this change of the dynamic regime of the
volcano. GPS data consist of two kinematic surveys carried out on 12 July, a few hours before the beginning of
the seismic swarm, and on 17 July, just after the onset of eruptive activity. A picture of the spatial distribution
of the sin-eruptive seismicity has been obtained using the HypoDD relocation algorithm based on the
double-difference (DD) technique. Modeling of GPS measurements reveals a southward motion of the upper
southern part of the volcano, driven by a NNW–SSE structure showing mainly left-lateral kinematics. Precise
hypocenter location evidences an aseismic zone at about sea level, where the magma upraise was
characterized by a much higher velocity and an abrupt westward shift, revealing the existence of a weakened
or ductile zone.
These results reveal how an intrusion of a dike can severely modify the shallow stress field, triggering
significant flank failure. In 2001, the intrusion was driven by a weakened surface, which might correspond to
a decollement plane of the portion of the volcano affected by flank instability, inducing an additional stress
testified by GPS measurements and seismic data, which led to an acceleration of the sliding flanks.
Description:
This work was funded by the Istituto Nazionale di Geofisica e
Vulcanologia and by the Dipartimento per la Protezione Civile (Italy).
Description:
Published
Description:
78–86
Description:
1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
Description:
1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
Description:
1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
Description:
3.2. Tettonica attiva
Description:
3.6. Fisica del vulcanismo
Description:
4.3. TTC - Scenari di pericolosità vulcanica
Description:
JCR Journal
Description:
reserved
Keywords:
stress release
;
dike
;
volcano-tectonics
;
flank instability
;
Mt. Etna
;
instrumental monitoring
;
04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous
;
04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes
;
04. Solid Earth::04.02. Exploration geophysics::04.02.99. General or miscellaneous
;
04. Solid Earth::04.03. Geodesy::04.03.99. General or miscellaneous
;
04. Solid Earth::04.03. Geodesy::04.03.07. Satellite geodesy
;
04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous
;
04. Solid Earth::04.04. Geology::04.04.09. Structural geology
;
04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
;
04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
;
04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous
;
04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress
;
04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
;
04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
;
04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
;
04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
;
04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
;
05. General::05.02. Data dissemination::05.02.99. General or miscellaneous
;
05. General::05.02. Data dissemination::05.02.02. Seismological data
;
05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
