Magnetotelluric fields in the frequency range 0.03 to 7 cycles per kilosecond: Part II. Geophysical interpretation

Abstract

. ~he power spectra computed in part 1 for Tbilisi, USSR, are lIsed to compute apparellt resistivity II) accordance with a formula developed by Cagniard. It is found that both compol~cnts of t he telluric field yield a value of 6 ohm meters for the appareJlt electrical reslstlvl~y of t he earth. The dnta do not extend over a sufficiently wide range of frequency to perlllit conclUSions about the stratification. There is no evidence of horizontal anisotropy of the earth's resistivit y. The magnetic po\ver spectrum for the earth's ambient field is corrected for t he transmis sion losses in the ionosphere to yield t he power spectrulll of the magnetic field incident on the earth. The major part of the variation \yith frequency is eliminated by this correction.