Publication Date:
2021-02-09
Description:
The Campi Flegrei caldera is characterized by well known episodes of fast uplift,
called ‘‘bradyseism,’’ the last of which produced 1.8 m of maximum vertical
displacement in the period 1982–1984. Less known is a particular aspect of Campi Flegrei
unrests, detected only in the last 20 years, namely, the occurrence of ‘‘miniuplift’’
episodes, characterized by relatively small positive vertical displacements (in the range
0.03–0.11 m). Miniuplift episodes occurred in 1989, 1994, and 2000 and, probably, one or
two times in the period 1972–1982. These small ground uplifts were also accompanied by
moderate seismicity. Each of them was followed by a short phase of relatively quick
subsidence, after which the previous rate of subsidence of the period was resumed. An
order-of-magnitude analysis of the forces, energy, and power that can cause the onset and
determine the evolution of these events is derived on the basis of a thermal-fluiddynamical approach. It allows the quantitative correlation of the power input from the
energy source with the rate of energy dissipation in the geologic system during the
miniuplifts. In order to assess the likelihood of our fluid-dynamical model for these
episodes, theoretical ground displacements have been computed. These displacements result
from the changes in pressure as a function of depth predicted by the fluid-dynamical model
for reasonable perturbations of the geothermal system, described as changes of the Pe´clet
number. Theoretical results agree extremely well with the observed amounts of the
miniuplifts.
Description:
Published
Description:
2363
Description:
2V. Struttura e sistema di alimentazione dei vulcani
Description:
3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici
Description:
4V. Processi pre-eruttivi
Description:
6A. Geochimica per l'ambiente e geologia medica
Description:
JCR Journal
Keywords:
hydrothermalism,
;
Phlegraen Fields
;
bradyseism
;
thermal fluid dynamical model
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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