Electromagnetic mapping using the Geonics EM34 is a rapid and non-invasive method of obtaining the bulk conductivity of the volume of soil and rock between two coils.

This is operated by two persons, with the coils spaced at 10 m, 20 m, or 40 m, with person moving the transmitter coil (Tx) in unison with the person moving the receiving coil (Rx)

Results are available instantly with no processing required

Exploration depths vary depending on the coil spacing and polarisation. Holding the coils vertically allows for Horizontal Dipole (HD) measurements between 7.5 m and 30 m depth, while holding the coils horizontally allows for Vertical Dipole (VD) measurements between 15 m and 60 m depth.

Also available is the GSSI EMP-400 Multi-Frequency EM conductivity meter. It operates similarly to the EM34 but with a fixed, 1.2 m, coil spacing. This allows for rapid mapping to be conducted by a single person