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 dynamic 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 reveal 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:
In press
Description:
1.1. TTC - Monitoraggio sismico del territorio nazionale
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:
3.5. Geologia e storia dei sistemi vulcanici
Description:
3.6. Fisica del vulcanismo
Description:
4.2. TTC - Scenari e mappe di pericolosità sismica
Description:
4.3. TTC - Scenari di pericolosità vulcanica
Description:
4.4. Scenari e mitigazione del rischio ambientale
Description:
JCR Journal
Description:
reserved
Keywords:
Stress release
;
Dike
;
Volcano-tectonics
;
Flank instability
;
Mount Etna
;
Instrumental monitoring
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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::04.03.06. Measurements and monitoring
;
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::04.04.01. Earthquake geology and paleoseismology
;
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::04.06.03. Earthquake source and dynamics
;
04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
;
04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
;
04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous
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04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
;
04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress
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04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
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04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
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04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
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04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
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04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
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05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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