Publication Date:
2017-04-04
Description:
Fissure eruptions may provide important information on the
shallow propagation of dikes at volcanoes. Somma-Vesuvius (Italy)
consists of the active Vesuvius cone, bordered to the north by the
remnants of the older Somma edifice. Historical chronicles are considered
to define the development of the 37 fissure eruptions between
A.D. 1631 and 1944. The 1631 fissure, which reopened the
magmatic conduit, migrated upward and was the only one triggered
by the subvertical propagation of a dike. The other 25 fissure
eruptions migrated downward, when the conduit was open,
through the lateral propagation of radial dikes. We suggest two
scenarios for the development of the fissures. When the summit
conduit is closed, the fissures are fed by vertically propagating
dikes. When the summit conduit is open, the fissures are fed by
laterally propagating dikes along the volcano slopes. Consistent
behaviors are found at other composite volcanoes, suggesting a
general application to our model, independent of the tectonic setting
and composition of magma. At Vesuvius, the historical data
set and our scenarios are used to predict the consequences of the
emplacement of fissures after the opening of the conduit. The results
suggest that, even though the probability of opening of vents
within the inhabited south and west slopes is negligible, the possibility
that these are reached by a lava flow remains significant.
Description:
Published
Description:
673-676
Description:
reserved
Keywords:
fissures
;
dike propagation
;
conduit
;
Vesuvius
;
04. Solid Earth::04.04. Geology::04.04.09. Structural geology
;
04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
;
04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Format:
308433 bytes
Format:
application/pdf
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