Publication Date:
2021-12-06
Description:
Studying seismicity in a volcanic environment provides important information on the state
of activity of volcanoes. The seismicity of the Neapolitan volcanoes, Campi Flegrei,
Vesuvius, and Ischia, shows distinctive characteristics for each volcano, coveringwide range of patterns and types. In this study we relocated some significant volcano-
tectonic earthquake swarms that occurred in Campi Flegrei and Vesuvius. Moreover, we
compared the earthquake occurrence evolution, the magnitude and the seismic energy
release of the three volcanoes. Also, we considered the results of seismic analysis in the
light of geochemical and ground deformation data that contribute to defining the state of
activity of volcanoes. In Campi Flegrei, which is experiencing a long term unrest, we
identified a seismogenic structure at shallow depth in Pisciarelli zone that has been
activated repeatedly. The increasing seismicity accompanies an escalation of the
hydrothermal activity and a ground uplift phase. At Vesuvius a very shallow seismicity
is recorded, which in recent years has shown an increase in terms of the number of events
per year. Earthquakes are usually located right beneath the crater axis. They are
concentrated in a volume affected by the hydrothermal system. Finally, Ischia generally
shows a low level of seismicity, however, in Casamicciola area events with a moderate
magnitude can occur and these are potentially capable of causing severe damage to the
town and population, due to their small hypocentral depth (typically 〈 2.5 km). After the
seismic crisis of August 21, 2017 (mainshock magnitude M 4), the seismicity returned to
a low level in terms of occurrence rate and magnitude of earthquakes. The seismicity of
these three different volcanic areas shows some common aspects that highlight a relevant
role of hydrothermal processes in the seismogenesis of volcanic areas. However, while the
main swarms in Campi Flegrei and most of the Vesuvian earthquakes are distributed along
conduit-like structures, the seismicity of Ischia is mainly located along faults. Furthermore,
the temporal evolution of seismicity in Neapolitan volcanic area suggests a concomitant
increase in the occurrence of earthquakes both in Campi Flegrei and Vesuvius in
recent years.
Description:
Published
Description:
662113
Description:
4V. Processi pre-eruttivi
Description:
JCR Journal
Keywords:
04.08. Volcanology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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