1. n. [Geophysics]

The product of conductivity and thickness, typically measured in units of siemens (S). In the inversion of electrical and electromagnetic measurements, the conductance of a layer or zone is usually much better determined than either the conductivity or thickness individually.

2. n. [Geophysics]

The reciprocal of resistance in a direct current circuit, measured in siemens (formerly mhos). In an alternating current circuit, conductance is the resistance divided by the square of impedance, also measured in siemens.