Resistivity and Radar surveys at the Archaeological site of Ercolano

In this paper we describe the application of GPR and resistivity (dipole-dipole) methods to an archeological investigation. The aim of this study was to obtain information about buried pre-Roman structures below the Roman residence “Casa dell’Atrio a Mosaico,” in the ancient town of Ercolano (Naples). A number of resistivity (dipole-dipole) and GPR profiles were carried out on the mosaic floor of the house. To perform resistivity profiles in a nondestructive way on the mosaic floor, special flat-base copper electrodes were used. The electrode spacing used was 1m and 0.5m. GPR data were collected using 100MHz and 500MHz antennas. The radar profiles were carried out primarily along the electrical profiles in order to obtain a direct comparison between the two methods. Both resistivity and GPR methods evidenced a number of structures buried at shallow depths. Both methods located a structure identified as a conductive body with electric parameters strongly contrasting those of the surrounding material. The archaeological interpretation of such structures is in terms of remnants of walls of pre-Roman houses and of a cistern used for collecting rain, connected to a pipe.