Publication Date:
2017-04-04
Description:
Volcanic edifices are often unable to support their own load, triggering the instability of their flanks. Many
analogue models have been aimed, especially in the last decade, at understanding the processes leading to
volcano flank instability; general behaviors were defined and the experimental results were compared to nature.
However, available data at well-studied unstable volcanoes may allow a deeper understanding of the
specific processes leading to instability, providing insights also at the local scale. Etna (Italy) constitutes a
suitable example for such a possibility, because of its well-monitored flank instability, for which different
triggering factors have been proposed in the last two decades. Among these factors, recent InSAR data highlight
the role played by magmatic intrusions and a weak basement, under a differential unbuttressing at the
volcano base. This study considers original and recently published experimental data to test these factors
possibly responsible for flank instability, with the final aim to better understand and summarize the conditions
leading to flank instability at Etna. In particular, we simulate the following processes: a) the longterm
activity of a lithospheric boundary, as the Malta Escarpment, separating the Ionian oceanic lithosphere
from the continental Sicilian lithosphere, below the most unstable east flank of the volcano; b) spreading due
to a weak basement, with different boundary conditions; c) the pressurization of a magmatic reservoir, as
that active during the 1994–2001 inflation period; d) dike emplacement, as observed during the major
2001 and 2002–2003 eruptions. The experimental results suggest that: 1) the long-term activity of a lithospheric
tectonic boundary may create a topographic slope which provides a differential buttressing at the
volcano base, a preparing factor to drive longer-term (〉105 years) instability on the east flank of the volcano;
2) volcano spreading (b104 years) has limited effect on flank instability at Etna; 3) magmatic intrusions
(b101 years), both in the form of Mogi-like sources or dikes, provide the most important conditions to trigger
flank instability on the shorter-term.
Description:
Thisworkwas partially funded by INGV and the Italian
DPC (DPC-INGV project V4 “Flank”).
Description:
Published
Description:
98-111
Description:
1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
Description:
3.2. Tettonica attiva
Description:
3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
Description:
3.6. Fisica del vulcanismo
Description:
JCR Journal
Description:
reserved
Keywords:
volcano instability
;
analogue modeling
;
Etna
;
unbuttressing
;
04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous
;
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::04.07. 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::04.08.02. Experimental volcanism
;
04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
;
04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
;
04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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