Publikationsdatum:
2017-04-04
Beschreibung:
Understanding how shallow magma is emplaced
within volcanoes is crucial for hazard assessment. The
2002–2003 Stromboli eruption provides the opportunity to
investigate shallow magma emplacement resulting from
orthogonal feeder dikes and its possible effects. Stromboli
erupted in 2002–2003, when effusive activity replaced
Strombolian activity. On December 28, a NE-SW fissure
propagated from the lava-filled northernmost summit crater.
On December 29, a NW-SE fissure propagated north of the
craters, feeding NW-SE aligned vents. On December 30,
this area collapsed, reaching the sea and generating a
tsunami. In mid February 2003, the NW-SE fissure became
inactive, while the NE-SW effusive fissure continued until
July. A model for shallow magma emplacement is proposed.
The lateral propagation of a NE-SW dike from the
northernmost crater was triggered. Below, a NW-SE dike,
propagating from the magma-filled NE tip of the NE-SW
elongated conduit, fed the NW-SE aligned vents. In
February, the conduit periphery became solidified,
freezing the NW-SE dike, and the transport of magma
was limited to the central part, focusing its rise below the
craters. This fed the NE-SW fissure until the supply
decreased further (July), returning to the ordinary level
sustaining Strombolian activity. Orthogonal dike
emplacement followed the trajectories of the maximum
(gravitational) stress s1, partly controlled by the irregular
topography of the uppermost edifice. The emplacement of
orthogonal dikes in a limited area is feasible at non-perfectly
conical active volcanoes, where the maximum gravitational
stress may show variations from a purely radial path.
Beschreibung:
Published
Beschreibung:
L17310
Beschreibung:
reserved
Schlagwort(e):
NONE
;
04. Solid Earth::04.04. Geology::04.04.09. Structural geology
;
04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress
;
04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
Repository-Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Materialart:
article
Format:
3375462 bytes
Format:
application/pdf
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