Electromagnetic (EM) Methods

EM methods generally measure the electrical resistivity of subsurface materials. There are several categories of EM instruments. They are differentiated from one another by either the way they generate or measure electrical potential resulting from the interaction of EM energy surface and subsurface materials. The main categories include Frequency Domain, Time Domain, and Very Low Frequency (FDEM, TDEM, and VLF, respectively). Utility locators and metal detectors are also based on EM technology. EM tools are typically deployed on the surface, in boreholes, and from marine and aerial platforms.

Electromagnetic (EM) Methods

We utilize EM instruments the following geophysical applications:

  • Mineral exploration
  • Organic and inorganic plume mapping
  • Buried waste delineation
  • Metallic tank and drum location
  • Metallic utility location
  • Buried object location
  • Salt water intrusion mapping
  • Vertical contact, fracture, or fault mapping
  • Depth to bedrock or clay profiling
  • Soil mapping
  • Rapid resistivity profiling

Our proprietary multichannel tool allows for rapid profiling of subsurface materials to a depth of more than nine meters as illustrated in the example below. It is also very useful for locating buried waste. This tool is commonly deployed for agricultural, engineering, environmental projects.

Electromagnetic (EM) Methods