Live 3D Resistivity Sounding Demo

A cut-away block of earth exposes the strata. Slide the electrode spacing wider and watch the glowing current paths dive deeper — when they reach the saturated sand, the aquifer lights up.

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Current electrodes A & B
Potential electrodes M & N
Current flow
Aquifer layer
  1. Current is injected through the outer electrodes A and B; the glowing particles trace its path through the ground.
  2. M and N measure only the voltage difference between the equipotentials they sit on — practically no current flows through them.
  3. Wider spacing drives the current deeper: through topsoil, into clay, and finally into the saturated sand where the aquifer glows.
  4. Each spacing gives one apparent resistivity reading — the full sounding curve is inverted to give layer depths for borewell siting.

Stylized cut-away view of a Schlumberger vertical electrical sounding. Values are illustrative — see the 2D explainer on the resistivity page for the full sounding curve.