Increased resolution of subsurface parameters from 1D magnetotelluric modeling
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Abstract
In electric and electromagnetic techniques, it is well known that the principle of equivalence poses a problem in the interpretation of subsurface layers. This means the inversion problem can provide the conductivity-thickness product more confidently than the individual parameters — conductivity and thickness — separately. The principle of equivalence corresponds to the middle layer in a three-layer earth structure. In order to resolve this problem, we have touched upon the different formulae of apparent resistivity proposed by earlier workers considering the real and imaginary parts of the impedance tensor and designed a new formula to compute apparent resistivity for different models. We observed that the application of our new formula for apparent resistivity using the combination of real and imaginary parts of the impedance has a better resolution as compared to earlier conventional formulae of apparent resistivity. These results have been demonstrated through both forward and inverse modeling schemes.
Key words
electromagnetics magnetotellurics apparent resistivity impedance resolutionPreview
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References
- Başokur, A.T. (1994), Definitions of apparent resistivity for the presentation of magnetotelluric sounding data, Geophys. Prospect. 42,2, 141–149, DOI: 10.1111/j.1365-2478.1994.tb00203.x.CrossRefGoogle Scholar
- Cagniard, L. (1953), Basic theory of the magneto-telluric method of geophysical prospecting, Geophysics 18,3, 605–635, DOI: 10.1190/1.1437915.CrossRefGoogle Scholar
- Garcia, X., and A.G. Jones (2008), Robust processing of magnetotelluric data in the AMT dead band using the continuous wavelet transform, Geophysics 73,6, F223–F234, DOI: 10.1190/1.2987375.CrossRefGoogle Scholar
- Harinarayana, T. (1999), Combination of EM and DC measurements for upper crustal studies, Surv. Geophys. 20,3–4, 257–278, DOI: 10.1023/A: 1006681604433.CrossRefGoogle Scholar
- Kant, Y., R.P. Singh, and N.K. Goel (1991), Magnetotelluric apparent resistivity — a comparative study of various definitions, Phys. Earth Planet. Int. 69,1–2, 8–13, DOI: 10.1016/0031-9201(91)90149-C.CrossRefGoogle Scholar
- Kunetz, G. (1972), Processing and interpretation of magnetotelluric soundings, Geophysics 37,6, 1005–1021, DOI: 10.1190/1.1440310.CrossRefGoogle Scholar
- Spies, B.R., and D.E. Eggers (1986), The use and misuse of apparent resistivity in electromagnetic methods, Geophysics 51,7, 1462–1471, DOI: 10.1190/1.1442194.CrossRefGoogle Scholar
- Vozoff, K. (1972), The magnetotelluric method in the exploration of sedimentary basins, Geophysics 37,1, 98–141, DOI: 10.1190/1.1440255.CrossRefGoogle Scholar