Electrical Exploration

Electrical Exploration is a geophysical method that measures the potential difference generated by passing an electric current through the ground, in order to reveal the subsurface resistivity distribution. Since underground rocks and soils have different electrical properties (electrical conductivity and resistivity), variations in resistivity can be used to infer subsurface structures and ground properties.

Direct Current Electrical Exploration (Representative Method)

Electrodes are placed on the ground surface, and a direct current is applied. By measuring the potential difference, resistivity is calculated to investigate subsurface structures.

IP (Induced Polarization) Electrical Exploration

This method utilizes the “chargeability” property of minerals (especially sulfide minerals and clay minerals) that can store electric charge. It is often used in combination with resistivity measurements and is widely applied in mineral resource exploration.

VLF-AC Electrical Exploration

An alternating current (on the order of kHz) is applied, and the potential difference is measured to determine resistivity and investigate subsurface structures. A key feature is that measurements can be performed even when the surface is covered with insulating materials such as asphalt, due to the capacitance effect.