GNGTS 2018 - 37° Convegno Nazionale

644 GNGTS 2018 S essione 3.2 electrodes was used. The set of acquired apparent resistivity data has been implemented in a single 3D model, which takes into account the elevation of the measure electrodes, and then appropriately processed, filtered and inverted using the ERT-Lab_64 software (Geostudi Astier S.r.l.). The 3D electrical resistivity model of the investigated subsoil has been obtained by using a three-dimensional finite element method with a tetrahedral mesh with a resolution of 50 cm. A rapid convergence of the model response to the eld data was reached, with a RMS error lower than 5%. Finally, by using the ViewLab3D software (Geostudi Astier S.r.l.), a three- dimensional visualization of the investigated slope in terms of electrical resistivity. Conclusions. The data processing shows a clear contrast between the sedimentary cover and the void created during the tunnel excavation, subsequently verified with direct investigations. Indeed, high-resistivity values, more than 800 Ωm they are characteristic (Fig. 2), in this case, the presence of cavities. While values between in the range 150 Ωm ≤ ρ ≤ 700 Ωm they are representative of unconsolidated material (Fig. 3). Conversely, low-resistivity values, in the range 1 Ωm ≤ ρ ≤ 150 Ωm (Fig. 3), values associated with the lithology rich in silts and clay which are present in the examined area. References Chambers, J.E., Wilkinson, P.B., Kuras, O., Ford, J.R., Gunn, D.A., Meldrum, P.I., Pennington, C.V.L., Weller, A.L., Hobbs, P.R.N. and Ogilvy, R.D. [2011] Three-dimensional geophysical anatomy of an active landslide in Lias Group mudrocks, Cleveland Basin, UK. Geomorphology , 125 , 472–84. Di Maio, R. and Piegari E. [2012] A study of stability analysis of pyroclastic covers based on electrical resistivity measurements. Journal of Geophysics and Engineering , 9 , 191–200, doi:10.1088/1742-2132/9/2/191. Di Maio, R., La Manna, M., Piegari, E., Mancini, C., Achilli, V. and Fabris, M. [2016] Multi-methodological geophysical exploration for the interpretation of the ancient landscape of Phaistos (Greece). Archaeological Prospection , 23 , 287–299, doi:10.1002/arp.1544. Drahor, M.G., Göktürkler, G., Berge, M.A., Kurtulmus, T.Ö. and Tuna, N. [2007] 3D resistivity imaging from an archaeological site in south-western Anatolia, Turkey: A case study. Near Surface Geophysics , 5 , 195–201. GROUND PENETRATING RADAR (GPR) DATA FROM “MARS”: THE SCANMARS EXPERIMENT IN AMADEE18 M. Ercoli 1 , A. Frigeri 2 , C. Pauselli 1 , G. Groemer 3 1 Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, Italy 2 Istituto di Astrofisica e Planetologia Spaziali, INAF, Rome, Italy 3 Österreichisches Weltraum Forum, Innsbruck, Austria Introduction. The characterization of the subsurface geology, particularly in environmental conditions potentially suitable to host water resources, represents one of the most important objectives of the planetary exploration. The geophysical techniques have all the potential and technology to be used as a tool for gathering such kind of information on other planets. Among those, the Ground Penetrating Radar (GPR) is surely suitable to provide high-resolution data about the structure, geometry and physical properties of the surveyed rocks (Jol et al. , 2009), also related to the moisture content in the shallow subsurface (Ercoli et al. , 2017). A proof of that is the incoming mission ExoMars2020, that will bring onboard a rover equipped with a GPR named WISDOM (Ciarletti et al. , 2017) on the Red Planet. For this reason, analogue planetary missions are mandatory to test new technologies and to refine workflows and operative procedures (Snook and Mendell, 2004; Groemer et al. , 2014; Rossi et al. , 2018). During the month of February 2018, the Austrian Space Forum (OeWF) organized a simulated mission, namedAmadee18, in the Dhofar desert in Oman. An international group of scientific teams were supervised by a Mission Support Center in Innsbruck (Austria), that also directed a small field