GPR and magnetic prospection: Large-scale, non-invasive mapping of buried archaeology


Archaeological excavation is one of the basic techniques for the investigation of past human societies. However, excavations are destructive and very locally focused. At the same time, non-destructive, or better non-invasive, methods are gaining more and more interest from archaeological decision makers who need to have large-scale information about archaeological structures at hand. Here, remote sensing and geophysical prospection are of prime importance. The most commonly used geophysical archaeological prospection methods in terms of area coverage and data collected, are magnetic prospection and Ground-Penetrating Radar (GPR) surveys, respectively. While both geophysical prospection methods have traditionally been focused on the investigation or detection of an individual archaeological site or structure (e.g. a building of a Roman villa, a prehistoric cemetery), the Vienna-based Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology (LBI ArchPro) has since 2010 – together with its international partner organizations – been developing motorised systems with multiple, densely-spaced sensors (magnetometers, magnetic gradiometers and GPR antennae) to considerably increase survey speed and efficiency. Rather than hectares, the mapping of entire archaeological landscapes became possible in this way. Using multiple Fluxgate gradiometer array carts towed by quad bikes and 16-channel GPR systems with unprecedented measurement density, the subsurface of several outstanding cultural heritage sites, such as the UNESCO world cultural heritage site of Stonehenge (UK) or the Roman urban landscape of Carnuntum (Austria), have been investigated in great detail without turning a single piece of turf. This presentation will outline some of the geophysical prospection principles and present several exceptional archaeological discoveries that resulted from the large-scale Stonehenge and Carnuntum studies. It will be shown how these new results changed and challenged our understanding of past landscapes. In the end, it should be clear that the combination of these fast and non-invasive geophysical prospection tools with the latest remote sensing techniques (such as airborne hyperspectral scanning) and targeted key-hole archaeological excavations, provides a fundamentally novel way to deal with endangered cultural heritage, both in exploration archaeology as well as for archaeological research.