Electromagnetic Conductivity (EM)

or Terrain Conductivity Surveys

Electromagnetic Conductivity (EM)

Electromagnetic conductivity (also known as terrain conductivity) measures the conductivity of the subsurface which includes soil, groundwater, rock, and objects buried in the ground. GeoModel, Inc. has conducted numerous electromagnetic conductivity (EM) surveys worldwide using EM instruments for various applications.

Electromagnetic conductivity (terrain conductivity) surveys are rapid and very accurate. The EM instruments are easily carried around the site and are used for a variety of purposes. Underground metal petroleum tanks can be located, metal underground utility pipes can be detected, contaminated groundwater can be mapped, and clay units can be identified.

GeoModel, Inc.'s geophysicists can perform an EM survey anywhere in the world and with short notice. Survey costs are reasonable.

Applications of Electromagnetic Conductivity (Terrain Conductivity):

• buried metallic objects
• underground metal storage tanks and drums
• buried metal utility lines
• landfills and trenches
• contaminant plumes
• bedrock fractures
• mining and minerals
• archaeology

Electromagnetic Conductivity (EM) (Terrain Conductivity) Surveys:

The instruments shown above can locate buried trenches, landfills, and inorganic or salt plumes. The shallow EM conductivity meter locates metal and measures ground conductivity to a depth of 20 feet (6 m). The EM metal detector locates metal to 10 feet and can more accurately define the metal target locations than the shallow EM conductivity meter. The deeper EM conductivity meter can measure ground conductivity to 100 feet (30 m). The EM conductivity instruments are excellent for locating inorganic and salt plumes from landfills and waste pits.

GeoModel, Inc. uses the new EM metal detection system which is twice as accurate as the standard EM metal detection system.

Examples of Electromagnetic Conductivity (Terrain Conductivity):

Site Characterization Surveys

Results of the EM survey shown as a "Site Scan Map"

Below is an aerial photograph of the site with the EM results (from above) superimposed onto it.

Subsurface Features and Site Conditions Investigated Using Electromagnetic Conductivity

GeoModel, Inc.'s professionals have successfully used Electromagnetic Conductivity methods to locate and delineate horizontal and vertical extents of buried metal (including utilities), sinkholes, landfill leachate, saltwater plumes, fracture zones, metal reinforced foundations, archaeological sites, and other surface and subsurface features and conditions. Three examples are shown below. The yellow, orange, pink,and red colors represent increasingly higher levels of terrain conductivity and the green and blue shades correspond with diminishing levels of ground conductivity (blue being at or close to background, neutral pH, freshwater, or native conditions).

Underground Metal Utility Location Surveys

Buried Drums, Tanks, and Other Features

EM results (below) at a site where steel drums were buried in concrete vaults.

Company Background

GeoModel, Inc. was founded in 1991 as a geophysical survey services and environmental consulting firm. The company principals have over 50 years of combined experience in the geophysical surveying and environmental field and have conducted numerous electromagnetic conductivity (terrain conductivity) surveys worldwide. All projects are conducted by registered professional geologists.

GeoModel, Inc. conducts surveys in every state.

Contact us to check the availability of a crew in your state.

Click here for worldwide surveys