Integrated Geophysical Investigation of a Buried Roman Villa in Pompeii

In archaeological research non-invasive techniques are commonly used to characterize a site or part of it. Among them, geophysical surveying is a valuable, non-destructive tool for archaeologists in evaluating sites and guiding excavation programmes within already discovered sites. In this paper we describe the results of an integrated geophysical survey carried out over a buried Roman Villa in Via Nolana, Pompeii. The area was partially unearthed in 1985 showing the remnants of a villa from the first Imperial Age. The excavation found also some frescos and traces of rural activities. The remnants were successively earthed again. The survey included high-resolution Geoelectrical, Magnetometric, Seismic and Ground Penetrating Radar measurements. They were performed both over the known buried structures and in the unexplored area immediately adjacent to the remnants, with the aim of verifying the presence of other unearthed villa structures beyond the explored area. Data processing included advanced filtering techniques, such as Discrete Wavelet Transform (DWT, Fedi & Florio, 2003), allowing an effective filtering of localized and directional noise. Furthermore, the use of multi-scale potentialfield techniques such as Enhanced Horizontal Derivative (EHD; Fedi & Florio, 2001) and Depth from Extreme Points (DEXP; Fedi, 2007) allowed positioning the lateral edges of the buried structures and characterizing their shape and depth. The results yielded by the different methods showed a rather good consistency in terms of position and size of the buried structures. Furthermore, the integration of the outcome of each geophysical technique reduced the intrinsic ambiguities of each method. Our interpretation revealed the presence of remnants in the unearthed area, in continuation of the already discovered section of the villa, and highlighted preferential areas for future archaeological diggings.