Publication Date:
2017-04-04
Description:
Since 1993, geodetic data obtained by different techniques (GPS, EDM, SAR, levelling) have
detected a consistent inflation of the Mt. Etna volcano. The inflation, culminating with the 1998–
2001 strong explosive activity from summit craters and recent 2001 and 2002 flank eruptions,
is interpreted in terms of magma ascent and refilling of the volcanic plumbing system and
reservoirs. We have modelled the 1993–1997 EDM and GPS data by 3-D pressurized sources
to infer the position and dimension of the magma reservoir. We have performed analytical
inversions of the observed deformation using both spheroidal and ellipsoidal sources embedded
in a homogeneous elastic half-space and by applying different inversion methods. Solutions
for these types of sources show evidence of a vertically elongated magma reservoir located
6 km beneath the summit craters. The maximum elevation of topography is comparable to
such depth and strong heterogeneities are inferred from seismic tomography; in order to assess
their importance, further 3-D numerical models, employing source parameters extracted from
analytical models, have been developed using the finite-element technique. The deformation
predicted by all the models considered shows a general agreement with the 1993–1997 data,
suggesting the primary role of a pressure source, while the complexities of the medium play
a minor role under elastic conditions. However, major discrepancies between data and models
are located in the SE sector, suggesting that sliding along potential detachment surfaces may
contribute to amplify deformation during the inflation. For the first time realistic features of
Mt. Etna are studied by a 3-D numerical model characterized by the topography and lateral
variations of elastic structure, providing a framework for a deeper insight into the relationships
between internal sources and tectonic structures.
Description:
Published
Description:
852-862
Description:
3.6. Fisica del vulcanismo
Description:
JCR Journal
Description:
reserved
Keywords:
finite-element methods
;
geodesy
;
lateral heterogeneity
;
volcanic activity
;
volcanic structure
;
04. Solid Earth::04.03. Geodesy::04.03.08. Theory and Models
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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