A Thermal Method for Archaeological Prospection: Preliminary Investigations

Interaction of archaeological features with the secular variation in surface heat flux generates an anomalous ground temperature distribution which can form the basis for a shallow geophysical prospecting tool. Earlier studies have concentrated on recording surface temperature disturbances via aerial thermography but these results can be biased towards minor variations in vegetation, albedo. and microclimate. A more promising approach is to record temperatures at a depth of 20cm using a simple probe. Anomalies at this depth arise from the interaction of objects with the annual heat‐flux cycle and other long‐term temperature variations. The amplitude, shape, and phase of anomalies have been modelled, together with the nature and magnitude of other, unwanted causes of ground temperature variation. Field equipment and data processing techniques for the direct‐contact approach to thermal prospection have undergone trails in the U.K. at Verulamium and Fountains Abbey.