Publication Date:
2017-04-04
Description:
Flank instability is common at volcanoes, even though
the subsurface structures, including the depth to a
detachment fault, remain poorly constrained. Here, we use
a multidisciplinary approach, applicable to most volcanoes,
to evaluate the detachment depth of the unstable NE flank
of Mt. Etna. InSAR observations of Mount Etna during
1995–2008 show a trapdoor subsidence of the upper NE
flank, with a maximum deformation against the NE Rift.
The trapdoor tilt was highest in magnitude in 2002–2004,
contemporaneous with the maximum rates of eastward slip
along the east flank. We explain this deformation as due to
a general eastward displacement of the flank, activating a
rotational detachment and forming a rollover anticline, the
head of which is against the NE Rift. Established 2D
rollover construction models, constrained by morphological
and structural data, suggest that the east‐dipping detachment
below the upper NE flank lies at around 4 km below the
surface. This depth is consistent with seismicity that clusters
above 2–3 km below sea level. Therefore, the episodically
unstable NE flank lies above an east‐dipping rotational
detachment confined by the NE Rift and Pernicana Fault.
Our approach, which combines short‐term (InSAR) and
long‐term (geological) observations, constrains the 3D
geometry and kinematics of part of the unstable flank of
Etna and may be applicable and effective to understand the
deeper structure of volcanoes undergoing flank instability
or unrest.
Description:
This work was partially funded by INGV
and the DPC‐INGV project “Flank”, and partially by the ASI (SRV project).
Description:
Published
Description:
L16304
Description:
1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
Description:
1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
Description:
1.10. TTC - Telerilevamento
Description:
3.2. Tettonica attiva
Description:
4.3. TTC - Scenari di pericolosità vulcanica
Description:
JCR Journal
Description:
reserved
Keywords:
flank instability
;
fault
;
InSAR
;
Etna
;
rollover
;
04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous
;
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::04.04.06. Rheology, friction, and structure of fault zones
;
04. Solid Earth::04.04. Geology::04.04.09. Structural geology
;
04. Solid Earth::04.04. Geology::04.04.11. Instruments and techniques
;
04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
;
04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous
;
04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
;
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::04.08.06. Volcano monitoring
;
04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
;
04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
;
05. General::05.08. Risk::05.08.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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