Earth Resistance
Earth Resistance can detect structural remains, stone and ditch features. It is often used to complement magnetometer surveys and can be used as a survey method in its own right. While magnetometer surveys depend on the magnetism of a feature, the Earth Resistance technique does not require magnetic enhancement as it investigates moisture change. It is particularly useful for medieval research such as castles and ecclesiastical sites where structural remains are present. Surveys are usually undertaken in a grid system either across the whole site or within areas of interest highlighted by a magnetometer survey.
Earth Resistance meters pass a small electrical current through the ground to map changes in moisture content in the soil, which can indicate the location of buried archaeological features. The instrument requires contact with the ground surface and surveys can be undertaken either using a hand held frame of probes placed on to the ground or a wheeled cart pulled across the ground.
Earth Resistance surveys allow for the detection of
- Stone or stone-filled features (including souterrains)
- Surfaces
- Buildings
- Ditches
- Pits
- Ponds
