Early signals of new volcanic unrest at Campi Flegrei caldera? Insights from geochemical data and physical simulations

For the fi rst time a physical model, constrained by monitoring
data, is used to derive a quantitative estimate of the evolution in time
of magmatic gases that enter a hydrothermal system of an active volcano.
The site is Campi Flegrei (west of Naples, in Italy), a caldera
that had a large ground infl ation in 1982–1984 followed by 20 yr of
subsidence. More recently the behavior of the system has changed:
the magmatic component of fumaroles has increased, swarms of
earthquakes are more frequent, and the ground has started a general
uplifting trend, indicating that the hydrothermal system undergoes
repeated injections of magmatic fl uid. Physical simulations of
the process show that total injected fl uid masses are the same order
of magnitude as those emitted during small to medium size volcanic
eruptions, and their cumulative curve highlights a current period of
increasing activity. Gas emission studies coupled with physical modeling
can be extremely effective in predicting magmatic evolution and
eruptive activity at volcanoes.

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