The subsurface surveying technique discussed herein is based on known electro-telluric principles. The electrical field that is detected and recorded by the surveying instrument is generated by the interaction of solar radiation with the Earth's ionosphere. This plasma envelope causes electromagnetic pulses to pass onto the Earth, and travel downward until they reach a change in conductivity caused by a change in lithological composition, porosity or mineral content. At that contact, a new electromagnetic pulse is generated that radiates to the surface, where it is detected by the survey unit. The frequency of the reradiated current is a function of the depth of the originating subsurface plane. The survey unit can be calibrated for this frequency and depth; hence, it can gather data from any other selected depth. The instrument then relays the characteristics of the detected current to the survey unit's operator (herein out called the surveyor), converting it to an audio signal. This is because the ear is the most sensitive recorder available.