Campi Flegrei Deep Drilling Project: an overview of main results and implications on caldera dynamic.

English Abstract:

During December 2012, in the framework of the “Campi Flegrei Deep Drilling Project” (CFDDP) a pilot

borehole was sunk into the caldera, to a depth of 501 m, 4.5 km ESE along the coast from Pozzuoli. The

primary purpose of the drilling is the understanding of caldera dynamic and is preparatory for the deeper

drilling at 3.5km of depth. The Campi Flegrei caldera experienced periodic phase of uplift and subsidence

accompanied by small to very large eruptions in the past, since the most recent one, occurred in 1538. Since

then, two main episodes of unrest, in 1969-72 and 1982-84, have resulted in a maximum net uplift at

Pozzuoli of more than 3 m. The second episode was accompanied by elevated rates of local seismicity,

which produced more than 16,000 earthquakes with recorded magnitudes between 0 and 4. The persistent

seismicity damaged older buildings in Pozzuoli and eventually led to the evacuation of 40,000 people. The

caldera is still active and the related high volcanic risk pushed the scientist to improve the knowledge of its

dynamic. In this context the CFDDP is aimed to obtain deep geological, geophysical and geochemical data to

constrain the models of unrest. Here we show the main results obtained from the drilling such as,

stratigraphy inferred from cuttings and coring, new permeability and stress data attained from different bore-

hole hydraulic tests and geochemical data of deep fluids.