Waterborne and on-land electrical surveys to suggest the geological evolution of a glacial lake in NW Italy

An extensive waterborne continuous vertical electrical sounding (CVES) survey consisting of 15 profiles, with a total length of about 19 km of acquisition, was carried out on the lake surface. The processing of the acquired profiles with a laterally constrained inversion (LCI) approach lead to the reconstruction of the lakebed sediment distribution, down to 10 m depth. Self potential (SP) data recorded on the lake surface have also been analyzed. Moreover, to verify the areal distribution of the deposits, three electrical resistivity tomographies (ERTs) were carried out on land near the northern and southern shores of the lake. The combination of the geophysical survey results with hydrogeological information and geological observations and interpretations allowed the characterization of the submerged deposits, the probable identification of the main areas of groundwater recharge and the preliminary reconstruction of the lake genesis.