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Abstract: A geoelectrical monitoring activity has been carried out to improve the geological and hydrogeological knowledge about the Varco d''Izzo landslide (Potenza, Basilicata, Southern Apennine, Italy), an active rotational–translational slide evolved in earth-flow. In this work we have focused on the Self-Potential (SP) method by applying three different SP measuring techniques and combining modern technologies for data acquisition and new methods for tomographic inversion. A SP map and three static SP tomographies have been carried out to better analyse the groundwater circulation system and to better reconstruct the geometry of the landslide body. In the accumulation zone, which is the area more exposed to the geomorphological activity, a new SP measuring strategy has been applied. This strategy, based on time-continuous 2D SP tomographies, helps identify water flow changes in subsurface by studying the time series of SP tomographic images. The analysis of time-dependent changes of water infiltration in near surface is the key to better understand the hydrogeological processes underlying the ground instability phenomena. The time-lapse analysis of tomographic images has allowed us not only to investigate the correlation between the temporal changes of SP signals and rainfall events, but also to quantify the range of these changes. The modification of the distribution of the SP source accumulation zones is associated with the dynamics of the groundwater flows. These preliminary results allow us to consider the SP tomographic method as a tool for geophysical monitoring of landslide areas and encourage to develop new measuring systems for near-real time applications. [Copyright &y& Elsevier]

Geoelectrical prospecting techniques have been applied in the study of the Varco d''Izzo landslide, one of the most interesting of its type. It is characterized by a rototranslational movement in the early stage and successively has undergone earthflow-type movement, which still continues today. This landslide is located in the Southern Apennine area near the city of Potenza (Italy). In particular, electrical resistivity tomographies (ERT) and self-potential surveys (SP) have been carried out by combining modern technologies for data acquisition and new methods for data inversion. The high resolution of the electrical tomographic images helped us to accurately describe the geometry of this landslide body. Joint interpretation of geophysical, geological and geomorphological data allowed us to identify the sliding surface, estimate the thickness of the mobilized material and describe the main patterns of the subsurface fluid flows in Varco d''Izzo landslide. [Copyright &y& Elsevier]