Electromagnetic Field Surveys
Knowledge in the Field
Electromagnetic surveys are used to investigate the electrical conductivity of the subsurface. They are often applied to locate conductive metallic objects, particularly if the target is not ferromagnetic. In addition, EM methods can rapidly map subsurface layers or features with different electrical resistivities such as ground ice, permafrost, salt infiltration in groundwater or contaminant plumes.
AGL Delivers
Aurora Geosciences offers shallow electromagnetic field surveys tailored to engineering investigations, including:
- Geonics EM-31 - For investigations to depths of 6 metres, this system provides conductivity information using low induction number quadrature responses and limited metal detection capability. It is very useful for mapping area subsurface apparent resistivity.
- Apex Parametrics MaxMin - The standard in horizontal loop electromagnetic instruments, this provides deep (50 m) apparent resistivity investigations using an exceptionally broad frequency spectrum (110 Hz to 56 KHz).
- Geonics EM-61 - A time domain instrument, it can be used to rapidly map subsurface conductive features such as pipes, metallic debris and rebar.