The Campi Flegrei Deep Drilling Project 'CFDDP': Understanding the Magma-Water Interplay at Large Calderas.

Campi Flegrei caldera, including part of the densely urbanised city of Naples represents, like several similar volcanic areas (Yellowstone and Long Valley, USA; Santorini, Greece; Iwo Jima, Japan, etc.), the most explosive volcanism on the Earth: that associated to collapse calderas. Understanding the mechanisms of activity of such areas is fundamental for volcanological research and also for correct evaluations of eruption hazard. Such areas, for instance are often subject to very peculiar unrest episodes, involving very large (up to several meters) uplift and subsidence episodes, generally without interbedded eruptions. Understanding the mechanisms of these unrests, and their possible links to impending eruptions, is fundamental for a correct assessment of eruption hazard and forecast. Campi Flegrei Deep Drilling Project (CFDDP) is a large International, multidisciplinary project, aimed to understand the mechanisms of caldera volcanism by studying directly, by crustal drilling, the deep structure of the Campi Flegrei caldera. One of the main aims of the project is to discriminate the mechanism for caldera unrest episodes. In this paper, we present simulations for the most likely of such mechanism, obtained by the use of COMSOL multiphysics. Results indicate that the most critical parameter to measure during the drilling, in order to discriminate the unrest mechanism, is permeability.