Electrical Resistivity Imaging
Electrical imaging is a geophysical method that provides a two or three dimensional resistivity image of the surface.
Electrical imaging can provide information about distinct subsurface boundaries and conditions that other geophysical methods cannot.
• Landfill investigations
• Bedrock mapping
• Void mapping
• Identifying layer thickness and depths.
• Site contamination surveys
EM method use a geophysical technique based on electromagnetic measurements of ground conductivity for imaging sub-surface structures.
As well as mapping out physical or chemical changes of sub-soil, EM imaging is often used to map sub-surface structures like remains of foundations or utilities.
Murphy Surveys can measure the electrical properties of the subsurface. A 2D map of electrical conductivity of the ground can be produced. This is achieved by carrying out the equipment along parallel lines with a sufficient spacing depending on purpose of the survey.
The depth of investigation can reach 6 meters but depending on size of objects. A single 200 litre (55 gal.) drum can be detected for example at depths greater than three meters.
As the survey is carried out with a GPS, on continuous collection mode, to ensure the most accurate location of possible targets for future exploration, it is a real fast and economic way to survey vast areas.