Publication Date:
2012-02-03
Description:
An edited version of this paper was published by AGU. Copyright (2010) American Geophysical Union.
Description:
Volcano deformation may occur under different conditions. To understand how a volcano deforms, as well as relations with magmatic activity, we studied Mt. Etna in detail using interferometric synthetic aperture radar (InSAR) data from 1994 to 2008. From 1994 to 2000, the volcano inflated with a linear behavior. The inflation was accompanied by eastward and westward slip on the eastern and western flanks, respectively. The portions proximal to the summit showed higher inflation rates, whereas the distal portions showed several sectors bounded by faults, in some cases behaving as rigid blocks. From 2000 to 2003, the deformation became nonlinear, especially on the proximal eastern and western flanks, showing marked eastward and westward displacements, respectively. This behavior resulted from the deformation induced by the emplacement of feeder dikes during the 2001 and 2002–2003 eruptions. From 2003 to 2008, the deformation approached linearity again, even though the overall pattern continued to be influenced by the emplacement of the dikes from 2001 to 2002. The eastward velocity on the eastern flank showed a marked asymmetry between the faster sectors to the north and those (largely inactive) to the south. In addition, from 1994 to 2008 part of the volcano base (south, west, and north lower slopes) experienced a consistent trend of uplift on the order of ∼0.5 cm/yr. This study reveals that the flanks of Etna have undergone a complex instability resulting from three main processes. In the long term (103–104 years), the load of the volcano is responsible for the development of a peripheral bulge. In the intermediate term (≤101 years, observed from 1994 to 2000), inflation due to the accumulation of magma induces a moderate and linear uplift and outward slip of the flanks. In the short term (≤1 year, observed from 2001 to 2002), the emplacement of feeder dikes along the NE and south rifts results in a nonlinear, focused, and asymmetric deformation on the eastern and western flanks. Deformation due to flank instability is widespread at Mt. Etna, regardless of volcanic activity, and remains by far the predominant type of deformation on the volcano.
Description:
ESA provided the SAR data (Cat‐1 no. 4532
and GEO Supersite initiative). The DEM was obtained from the SRTM
archive, while the ERS‐1/2 orbits are courtesy of the TU‐Delft, The Netherlands.
This work was partially funded by INGV and the Italian DPC (DPCINGV
project V4 “Flank”), the Italian DPC (under special agreement with
IREA‐CNR), and the Italian Space Agency under contract “sistema rischio
vulcanico (SRV).” The authors thank Francesco Casu, Paolo Berardino,
and Riccardo Lanari for their support and Geoff Wadge and Michael Poland
for their helpful and constructive review of the manuscript.
Description:
Published
Description:
B10405
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:
3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
Description:
3.6. Fisica del vulcanismo
Description:
4.3. TTC - Scenari di pericolosità vulcanica
Description:
JCR Journal
Description:
reserved
Keywords:
Flank instability
;
InSAR
;
volcanoes
;
Etna
;
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::04.04.06. 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::04.08.03. 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::05.02.03. Volcanic eruptions
;
05. General::05.04. Instrumentation and techniques of general interest::05.04.99. General or miscellaneous
;
05. General::05.08. Risk::05.08.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
