Subsurface Visualization Using Ground-Penetrating Radar for Archaeological Site Preparation on the Northern Slope of Somma-Vesuvius: A Roman Site, Pollena Trocchia, Italy

The use of non-invasive geophysical techniques is becoming increasingly important in archaeological site studies as a means to increase the efficiency of excavation and to thereby avoid unnecessary disturbance. Ground-penetrating radar (GPR) surveys were performed over an orthogonal grid in order to guide the decision-making process for planning excavation at a Roman site in Pollena Trocchia (Italy), located just off the NW flank of Somma-Vesuvius. Archaeological planning for this site is complicated by contextual disruption and intermittent backfill, sometimes exacerbated by its proximity to building sites and by its use as a landfill, and by prior archaeological excavation and subsequent remediation. From a geophysical point of view, the site at Pollena Trocchia provided an ideal test-bed for visualization experiments (a) because the ground surface was readily cleared and smoothed by earth-moving machinery and (b) because the soil derived from geologically recent volcanic ash was dry at the time of the survey. State-of-the-art geophysical visualization techniques were applied to the pseudo-3D GPR data using conventional displays, seismic attribute analysis, and waveform connectivity schemes as employed in petroleum exploration. In this way, we assess the value of applying strategies adapted from industrial 3D seismic imaging to the problem of defining the effects of previous disturbance at a complex archaeological site.