Studio di fattibilità tecnico-scientifico per l’installazione di un profilometro per il monitoraggio delle deformazioni del fondo mare nel Golfo di Pozzuoli, Campi Flegrei

Abstract

This report presents a feasibility study aimed to use an innovative instrumentation for the measurement and real-time monitoring of the vertical deformations of the sea floor, which will be integrated in the MEDUSA permanent marine infrastructure installed in the Gulf of Pozzuoli, the submerged part of the Campi Flegrei caldera. The instrumentation consists of a Digital Profile Gauge, which is currently owned by ENI S.p.A. (Italy) in the framework of the agreement between these and INGV. The digital profile gauge consists of a flexible hydraulic circuit containing several pressure sensors, which measure the difference in pressure between one of these and another one used as reference point. This difference is proportional to their relative vertical displacement. The characteristics of the fluid filling the circuit and the quality of the pressure sensors, allows measurements with a sub-centimetric accuracy. The digital profile gauge consists of 15 segments, 200 m long each, which can be arranged in one or more alignments for a total length of 3 km, with sensor spacing every 100 m. In the report a description of the instrumentation and the environmental and technical installation requirements are presented and some installation configurations are proposed. The criteria for choosing these configurations are described; they take into account the technical requirements of the instrumentation, including the constraints for the integration with the MEDUSA infrastructure, the scientific validity of the installation and its contribution to strengthening the surveillance and monitoring system of the study area, managed by the INGV, Sezione di Napoli - Osservatorio Vesuviano. An assessment of the vertical deformations that can be measured from the digital profile gauge was calculated using a simple descriptive model of the deformation field that is well suited to the data collected both from the monitoring networks present on land and by MEDUSA marine infrastructure.