Survey with a Resistivity Metre:
Although results obtained with a resistivity metre in 1993 were of interest, a fluxgate gradiometer was preferred because of its greater efficiency and more rapid collection of data. Another limiting factor is that electrical resistivity survey can only be done if the ground is moist. In recent seasons, however, use of a single mobile frame has increased efficiency somewhat. In certain areas the new results are stunning.
 

Resistivity Map:
This image covers part of a larger area selected for a comparative study of geophysical methods at Kerkenes. In this area, of the city, measuring of 120 x 80m, none of the buildings can be seen on the surface. Unlike with gradiometer imagery, heat induced alterations to magnetic properties have no effect, although fire alteration to mud-brick and other materials is significant. The background is strongly influenced by hydrology, a streambed accounting for the broad sweep of white. The two parallel white lines that run diagonally across the picture indicate a tractor track.

Geo-magnetic Induction:
In 2000, for the first time at Kerkenes, Harry von der Osten Woldenburg, great nephew of Hans Henning von der Osten, employed Electromagnetic Induction with a high-density sampling strategy. One advantage of pioneering this technique at Kerkenes is that new results can be compared with the very good data collected using other methods.

Comparing Techniques:
In this figure imagery from three different geophysical survey methods can be compared. This one-hectare (100 x 100m) survey area is in the central area where the features are buried under 30 to 50cm of washed soil. When sufficient comparative data becomes available, GIS can be used to analyse results and formulate an understanding of causes and effects.

The Electromagnetic Induction Plot:
The Electromagnetic Induction plot reveals most of the features seen in the other two images. This new method holds great potential for future studies.

Geomagnetic Survey:
Geomagnetic survey with a fluxgate gradiometer reveals many of the buildings in very considerable detail. In some instances the position of burnt doorposts can be seen (e.g. grid 740/1720 not seen in the two other images).

Electrical Resistivity:
Electrical resistivity survey highlights details with remarkable clarity where there is a favourable combination of conditions.