We use electrical conductivity (EM), electrical resistivity and Ground Penetrating Radar geophysical techniques for site investigations.
Electrical Conductivity (EM)
Resistivity basically measures the inverse of conductivity such that sands and gravels have a high resistance and clays have a low resistance to an induced electrical current. Interpretation of the resistivity methods produces a 'cross section' through the ground. In the image below (underneath our East Yorkshire office) the red colours represent dry chalk, the pale blue colours represent chalk below the water table and the dark blue colours represent boulder clay.
Ground Penertrating Radar (GPR)
We have also successfully used our utility location location equipment (GPR) in conjunction with our geotechnical measuring equipment (Mackintosh Probe) to map variations in peat thickness.