Once again the sun came out and the landscape was bathed in that clear light that is so redolent of northern Scotland.

The festival also gave University of the Highlands and Islands (UHI) students on site practical experience of archaeological techniques. Here, one of the UHI students poses for a photograph in front of Bruan Broch while completing the magnotometry survey .​

Geophysical survey in archaeology uses a wide range of non-intrusive techniques to reveal buried archaeological features, sites and landscapes.

Geophysical survey is a rapid and cost-effective means of exploring large areas and is used widely in commercial and research archaeology. It is quite often one of the first techniques to be employed on a site, prior to ground-breaking, and the results can be used to determine the location of any trenches.

Some techniques complement each other, such as magnetic survey and earth resistance survey, which will be used in this project. 

Magnetic survey measures localized variations in the earth’s magnetic field caused by features in the top metre or so of the ground. The technique is especially suited to locating ditches, pits, pottery and tile kilns, hearths and ovens, ferrous debris, and burnt material.

Users need to be free of magnetic material, such as zips on clothing, when carrying out the survey.

ORCA briefing to volunteers