Publication Date:
2017-04-04
Description:
Ischia is an active volcanic island in the Gulf of
Naples whose history has been dominated by a calderaforming
eruption (ca. 55 ka) and resurgence phenomena
that have affected the caldera floor and generated a net
uplift of about 900 m since 33 ka. The results of new
geomorphological, stratigraphical and textural investigations
of the products of gravitational movements triggered
by volcano-tectonic events have been combined with the
information arising from a reinterpretation of historical
chronicles on natural phenomena such as earthquakes,
ground deformation, gravitational movements and volcanic
eruptions. The combined interpretation of all these data
shows that gravitational movements, coeval to volcanic
activity and uplift events related to the long-lasting
resurgence, have affected the highly fractured marginal
portions of the most uplifted Mt. Epomeo blocks. Such
movements, mostly occurring since 3 ka, include debris
avalanches; large debris flows (lahars); smaller mass
movements (rock falls, slumps, debris and rock slides, and
small debris flows); and deep-seated gravitational slope
deformation. The occurrence of submarine deposits linked
with subaerial deposits of the most voluminous mass
movements clearly shows that the debris avalanches impacted on the sea. The obtained results corroborate the
hypothesis that the behaviour of the Ischia volcano is based
on an intimate interplay among magmatism, resurgence
dynamics, fault generation, seismicity, slope oversteepening
and instability, and eruptions. They also highlight that
volcano-tectonically triggered mass movements are a
potentially hazardous phenomena that have to be taken
into account in any attempt to assess volcanic and related
hazards at Ischia. Furthermore, the largest mass movements
could also flow into the sea, generating tsunami waves that
could impact on the island’s coast as well as on the
neighbouring and densely inhabited coast of the Neapolitan
area.
Description:
Published
Description:
79-106
Description:
3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
Description:
JCR Journal
Description:
reserved
Keywords:
Ischia .
;
Caldera resurgence
;
Slope instability
;
Debris avalanche
;
Lahar
;
Volcanic and related hazards
;
04. Solid Earth::04.04. Geology::04.04.03. Geomorphology
;
04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport
;
04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy
;
04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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