Archaeological Geophysics Overview

Geophysics can be generally defined as the application of physics to investigations of the Earth. Archaeological geophysics uses the principles of geophysics to investigate known buried archaeological remains and to assess whether archaeological remains are present.

Stratascan is one of Britain's leading survey companies undertaking archaeological geophysics to investigate both rural and urban locations. We use non-invasive techniques to examine the shallow subsurface which is important in archaeology as historical sites are left undisturbed.

We are an 'IFA Registered Organisation' indicating that the national body setting standards in archaeology has accredited our company.

Most of our investigations survey the top 1.5m of the subsurface but some of our techniques can survey to 5m or more. We are looking for differences in the physical properties of the subsurface. These 'anomalies' represent a contrast with the parent soils or subsurface materials. For example, a buried wall will have a different resistance to the surrounding soil. This allows us to make an assessment of the archaeological potential of a site and advise on to the best locations for further investigation.

A range of techniques are available which are discussed in greater detail in the Reconnaissance Techniques and Detailed Techniques sections of this menu.

Reconnaissance techniques help provide a basic assessment of previous activity and possible archaeology on a site. The methods we employ at Stratascan include Magnetic Susceptibility, Magnetometer Scanning and Metal Detecting. The results of a reconnaissance survey are used to target areas for more detailed geophysical techniques.

Detailed techniques include Magnetometry, Resistivity, Ground Penetrating Radar (GPR) and Electromagnetics. Using these methods archaeological features such as ditches, foundations, pits, banks etc. can be plotted from the variation in readings across a site. These variations or anomolies are displayed in greyscale or colour images that allow an interpretation to be made of the archaeology below the surface.

Although most of our work is carried out in conjunction with archaeological units forming part of evaluations of sites being considered for development, we have also carried out research projects including, for example, surveys of sites being considered for scheduling. Other clients include consultants, architects, developers, councils and private individuals.

We have also carried out work for the media, including appearances on BBC Here and Now, Time Team, House Detectives, Meet the Ancestors and Lost Gardens.