Dictionary:Cagniard apparent resistivity
(cāgn’ yard) 1. A resistivity calculated from orthogonal electric and magnetic field measurements, used for magnetotelluric measurements in a layered earth. For more complicated structure, the full tensor impedance must be considered. 2. In the magnetotelluric method, an apparent resistivity in ohm-meters at period T obtained from 0.2T |Z|2, where Z is the Cagniard impedance (q.v.).