GNGTS 2022 - Atti del 40° Convegno Nazionale

GNGTS 2022 Sessione 1.3 167 DESIGN AND REALIZATION OF A MEASUREMENT NODE FOR GRAVIMETRIC APPLICATIONS J.J. Jiménez 1,3 , A. Albano 2 , V. Carbone 2 , F. Lamonaca 1 1 Università della Calabria, Dipartimento di Ingegneria Informatica, Modellistica, Elettronica e Sistemistica 2 Università della Calabria, Dipartimento di Fisica 3 Universidad San Francisco de Quito, Instituto de Micro y Nanoelectrónica Abstract. This paper focuses on the design and realization of a gravitational measurement node in Cosenza, southern Italy. This zone is of great interest from a geological point of view, as it is situated on the Calabrian arc, a zone known for its high seismic and volcanic activity. Tidal variations are utilized by researchers since comparing present and past records which can help detect seismic or volcanic anomalies which could lead to the timely detection of a possible natural disaster. This measurement node monitors tidal variations via gravitational alterations utilizing a LaCoste e Romberg Model G-1089 gravimeter. To further complete the gravitational node, measurements of correlated parameters of the gravitational force are also monitored. These parameters are surface inclination, barometric pressure, and temperature. This paper starts by discussing the importance of tidal variation monitoring in the region. A description of the technical features of the diverse hardware elements is followed by an explanation of the onsite implementation of the gravitational node. Finally, the acquired data is confronted with theorical values confirming the effectiveness of the proposed measurement node. Introduction. Southern Italy, in particular Calabria, is an area of geophysical interest due to its high seismic and volcanic activity. With several active volcanoes from the Calabrian arc such as Etna, Stromboli Vulcano and Paranea in vicinity of highly populated areas, unexpected natural disasters could bring a lot of human and material loss. Furthermore, underground volcanoes such as Marsili, a submerged volcano located near the coast of Calabria, could induce a tsunami in case of an eruptive event, or in case of a collapse of the volcanic structure. One way to be prepared for a natural disaster is tidal analysis. Constant comparison of records of the amplitudes and phases of the tidal signals with models of the gravitational records are useful to timely detect volcanic and seismic actions (Albano, 2013). For this reason, monitoring of tidal variations via gravitational nodes are important, and this research focuses on creating a gravitational station in the area. In 2011 a clinogravimetric station started operating at Università della Calabria. However, due to the lack of proper maintenance the station stopped acquiring data in 2016. After obtaining positive results from an initial assessment of the equipment in November 2011, the station was completely reactivated by the end of March 2022. In this paper it is proposed a measurement node for gravimetric applications designed to guaranty a multiparametric acquisition of the tidal signals and of the magnitude influencing their acquisition. Design of the Measurement Node. The gravitational station implemented is in charge of monitoring several parameters that have effects on the gravitational accelerations, according to models presented in (Albano, 2015). The parameters of interest for this station are: gravitational acceleration, inclination on the N-S and E-W axis, temperature and barometric pressure. For the gravitational acceleration, the gravimeter G-1089 from LaCoste & Romberg was utilized. It has an operating range of 7000mGal, with a resolution of 0.005mGal and an accuracy of 0.04 mGal and contains three analog outputs (LaCoste, n/d). Two of them to measure the central and lateral levels and one for the feedback channel that gives information about the gravitational acceleration. For its correct operation, the gravimeter must maintain an internal temperature of 55.85 °C ± 0.04 °C. A polyurethane box was placed outside of the device to