Publication Date:
2017-04-04
Description:
Long duration time-series of the chemical composition of fumaroles and of soil CO2 flux reveal
that important variations in the activity of the Solfatara fumarolic field, the most important
hydrothermal site of Campi Flegrei, occurred in the 2000-2008 period. A continuous increase of the
CO2 concentrations, and a general decrease of the CH4 concentrations are interpreted as the
consequence of the increment of the relative amount of magmatic fluids, rich in CO2 and poor in
CH4, hosted by the hydrothermal system. Contemporaneously, the H2O-CO2-He-N2 gas system
shows remarkable compositional variations in the samples collected after July 2000 with respect to
the previous ones, indicating the progressive arrival at the surface of a magmatic component
different from that involved in the 1983-84 episode of volcanic unrest (1983-1984 bradyseism).
The change starts in 2000 concurrently with the occurrence of relatively deep, long-period seismic
events which were the indicator of the opening of an easy-ascent pathway for the transfer of
magmatic fluids towards the shallower, brittle domain hosting the hydrothermal system. Since 2000,
this magmatic gas source is active and causes ground deformations, seismicity as well as the
expansion of the area affected by soil degassing of deeply derived CO2. Even though the activity
will most probably be limited to the expulsion of large amounts of gases and thermal energy, as
observed in other volcanoes and in the past activity of Campi Flegrei, the behavior of the system in
the future is, at the moment, unpredictable.
Description:
Published
Description:
B03205
Description:
1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
Description:
2.4. TTC - Laboratori di geochimica dei fluidi
Description:
4.5. Studi sul degassamento naturale e sui gas petroliferi
Description:
JCR Journal
Description:
reserved
Keywords:
Campi Flegrei
;
CO2
;
03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems
;
04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
;
04. Solid Earth::04.08. Volcanology::04.08.01. Gases
;
04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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