Geophysical survey is ground-based physical sensing techniques used for archaeological imaging or mapping. It involves measuring the physical properties of the ground (or structure) and determining if there are any variations or 'anomalies' in the background readings. The occurrence of anomalies can indicate the presence of a feature(s) or changes in a material's composition. Geophysics is a broad discipline with a wide range of techniques that can be used in a variety of sectors.

There are a wide variety of geophysical techniques available, each one measuring different physical properties and each being more or less sensitive to different types of feature. The suitability of any given technique will depend on the sites specific conditions and the type and composition of likely target features.

One of the main advantages to using geophysics is that the entire site can be sampled fairly rapidly for a relatively low cost. The data acquired can then allow the optimal intrusive investigation to be determined which will result in more detailed, comprehensive information being obtained about a site. This will usually result in overall project cost savings. Another major benefit to carrying out a geophysical survey is that the ground or structure is not disturbed so there is no exposure to buried hazards or chance of creating contaminant pathways. Features can be identified without the risk of damaging them, which in the case of buried utility apparatus is critical.

Arab Geotech will tailor the survey to meet the individual project requirements and on larger sites can undertake trial surveys to assess which techniques will provide the required results. It is a key aspect of our services that we produce concise, clear interpretations and reports.

The most common techniques used for geophysical survey are seismic, electromagnetic and magnetic methods, ground penetrating radar, electrical resistance (or conductivity) meters and gravimetry.