Abstract
The Earth’s magnetic field (emf) measured at or above the Earth’s surface has two main components of internal origin: a primary (or main) field which is originated in the outer core and appears as large scale features at the Earth’s surface, and a secondary field which is due to both induced and remanent magnetization of high susceptibility ferrimagnetic minerals occurring in crustal rocks. The latter field is much weaker than the main field and it is locally variable according to the nature of the underlying crustal rocks. These two components of the emf appear clearly in a power spectrum analysis of the emf intensity along a world encircling profile (Alldredge et al., 1963). The energy of the spectrum is concentrated at wavelengths greater than about 2,000 km and smaller than 400–500 km (Fig.1). In the representation of the emf as an infinite series of spherical harmonic functions, the main field therefore is described by the harmonics up to order and degree about (13, 13) and the field of crustal origin by harmonics higher than (40, 40).
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Bibliography
Alldredge, L.R., Van Vookhis, G.D., and Davis, T.M., 1963, A magnetic profile around the world, J. Geophys. Res., 68:3679.
Almeida, F.F., de, 1977, Ocraton de Sao Francisco, Rev. Brasil Geoc., 7: 349–364.
Barraclough, D.R., Harwood, J.M., Leaton, B.R., and Malin S.R.C., 1978, A definitive model of the geomagnetic field and its secular variation for 1965. I. Derivation of model and comparison with the IGRF, Geophys. J.R. Astr. Soc., 55:111–121.
Bhattacharryya, B.K., Lev, L.K., 1975, Analysis of magnetic anomalies over Yellowstone National Park: mapping of Curie point isothermal surface for geothermal reconnaissance, J. Geophys. Res., 80:4416–4465.
Blackman, R.B., Tuckey, J.W., 1959, The measurement of Power Spectra from the point of view of communication engineering. New York, Dover Publ.
Blitzkow, D., Gasparini, P., Mantovani, M.S.M., Sa, N.C., de, 1979, Crustal structures of Southeastern Minas Gerais, Brazil, deduced by gravity measuments, Rev. Brasil, Geoc., 9:38–47.
Burg, J.P., 1967, Maximum enthropy spectral analysis. Paper presented at 37th Ann. Int. JEG Meeting Oklahoma.
Cordani, U.G., Amaral, G., Kawashita, K., 1973, The Precambrian evolution of South America, Geol. Rund., 62:309:317.
Corrado, G., Gasparini, P., Mantovani, M.S.M., Rapolla, A., 1979, Depth of Curie temperature computed from aeromagnetic anomalies in Southeastern Minas Gerais, Brazil, Rev. Brasileira de Geociencias, 9:33–38.
Corrado, G., Pinna, E., Rapolla, A., 1977, The magnetic field of Italy: description and analysis of the new T, Z and H maps between 40° N and 44° N, Boll. Geof. Teor. e Appl., vol. XX, 75:140–156.
Dawson, E., and Newitt, L.R., 1978, IGRF comparisons, Phys. of the Earth and Plan. Int., 16:P1–P6.
Gasparini, P., Mantovani, M.S.M., Corrado, G., and Rapolla, A., 1979, Depth of Curie temperature in continental shields: a compositional Boundary?, Nature 278 N°5707:845–846.
Haggerty, S.F., 1978, Mineralogical constraints on Curie isotherms in deep crustal magnetic anomalies, Geophys. Res. Letters, 5:105–108.
IAGA Division 1 Study Group, 1976, International geomagnetic reference field 1975, EOS (Trans. Am. Geophys. Union), 57:120-121.
Kanasewich, E.R., 1975, Time sequence analysis in geophysics Univ. of Alberta Press, Edmonton, Canada.
Krutikhovskaya, Z.A., and Pashkevich, I.K., 1979, Long-wavelength magnetic anomalies as a sorce of information about deep crustal structure, J. Geophys., 46:301–317.
Kulhanek, O., 1976, Introduction to digital filtering in geophysics Elsevier Publ. Co. Amsterdam.
Shuey, R.T., Schellinger, D.K., Tripp, A.C., Alley, L.B., 1977, Curie depth determination from aeromagnetic spectra, Geophys. J.R. Astr. Soc., 50:75:101.
Smith, R.B., Shuey, R.T., Pelton, J.R., Bailey, J.P., 1977, yellostone hot spot: contemporary tectonics and crustal properties from earthquake and aeromagnetic data, J. Geophys. Res., 82:3665–3676.
Spector, A., Grant, F.S., 1970, Statistical models for interpreting aeromagnetic data, Geophysics, 35:293–302.
Wasilewski, P.J., Thomas, H.H., Mayhew, M.A., 1979, The Mono as a magnetic boundary, Geophys. Res. Letters, 6:541–544.
Willye, P., 1971, The dynamic Earth, J. Wiley and Sons, New York.
Zmuda, A.J., 1971, World Magnetic Survey 1957–1969, IAGA Bulletin n. 28. IUGG Publication 206 pp.
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© 1981 Plenum Press, New York
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Gasparini, P., Mantovani, M.S.M., Shukowsky, W. (1981). Interpretation of Long Wavelength Magnetic Anomalies. In: Cassinis, R. (eds) The Solution of the Inverse Problem in Geophysical Interpretation. Ettore Majorana International Science Series, vol 11. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-3962-5_11
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DOI: https://doi.org/10.1007/978-1-4684-3962-5_11
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