Publication Date:
2017-04-04
Description:
Our study is aimed to develop a 3D physical model of the Campi Flegrei geothermal system, in order to achieve a
more accurate and comprehensive representation of the hydrothermal processes occurring in the caldera. The
new model, developed by using the TOUGH2 code simulator, accounts for the caldera rocks' physical properties,
bathymetry and water table topography. In particular, the computational domain is constrained by density values
obtained by tomographic inversion of gravity data collected during several surveys at CF both onshore and offshore
the caldera. Empirical relations between density and porosity and between porosity and permeability, derived
by published data on samples cored in deep wells or collected in outcrops, allowed us to characterize the
main rocks physical parameters controlling the dynamic of the CF geothermal system. We have performed and
compared several simulations investigating the effects of the injection at depth, underneath Solfatara crater, of
a hot gaseous mixture rich in CO2. We show that, with respect to the available literature on 2D axisymmetric
models, the effects of the water table topography together with the bathymetry and the heterogeneous distribution
of the rocks' physical properties, lead to important differences in the hydrothermal circulation of fluids at CF.
These constraints allow the activation of convective cells with different behaviors, which produce variable patterns
of temperature inside the hydrothermal system. As a consequence, the predominant effect is again represented
by a central plume below the Solfatara crater, but with a non-axisymmetric structure and a wider
extension. Additionally, high temperature zones are present near the coastline and in the middle part of the submerged
area of the caldera with a SE–NW alignment.
Moreover, our results indicate that, the submerged part of the CF caldera would deserve a more accurate study
and survey, being affected by phenomenon of heating and degassing. This information could be very useful in
terms of hazard assessment and volcanic risk mitigation in such an active and densely inhabited volcanic and
geothermal area.
Description:
Published
Description:
172-182
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:
restricted
Keywords:
Campi Flegrei
;
Geothermal system
;
3D model
;
Water table topography
;
03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring
;
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::04.08.07. Instruments and techniques
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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