Publication Date:
2017-04-04
Description:
The results of a detailed stratigraphic study, carried out in the areas located to the east and south-west of Mt. Epomeo at Ischia,
are presented and compared with those of previous geological, archaeological and historical investigations to show the
relationships among caldera resurgence, volcanism and slope instability in the past 5.5 ka. Resurgence at Ischia began at about
30 ka B.P. and occurred through intermittent uplifting and tectonic quietness phases. During the past 5.5 ka reactivation of faults
and related volcanic activity was accompanied by emplacement of deposits generated by surface gravitational movements. These
deposits were generated in four main phases, dated between 5.5 and 2.9 ka, around 2.9 ka, between 2.6 and 2.3 ka, and between 2.3
and 1.9 ka, respectively. Deposits formed by gravitational movements preceded and followed the emplacement of volcanic rocks,
testifying that slope instability was induced by vertical movements, which also activated and/or reactivated faults and fractures that
fed volcanism. The results of this study therefore suggest that, although slope failure can occur as a consequence of a variety of
factors, resurgence has to be considered a factor inducing a particularly intense slope instability. Resurgence is accompanied by
activation of faults and renewal of volcanism, causing oversteepening of the slopes and generating seismicity that could trigger
surface gravitational movements. Furthermore, the availability of large amount of loose material, rapidly accumulated along the
slopes during eruptions, favors landslide generation.
Description:
Published
Description:
148–165
Description:
reserved
Keywords:
Slope instability
;
Volcanism
;
Volcano-tectonism
;
Resurgent calderas
;
Ischia
;
04. Solid Earth::04.04. Geology::04.04.03. Geomorphology
;
04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy
;
04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Format:
1454013 bytes
Format:
application/pdf
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