Abstract
The residual dipole moment of the outer spherical shell of the Moon, magnetized in the field of an internal dipole is calculated for the case when the permeability of the shell differs from unity. It is shown that, using an average value of surface magnetization from returned lunar crystalline rock samples and a global figure for the lunar permeability of 1.012, that a residual moment of the order of 1015 to 1016 Am2 is expected. This value is some two or three orders of magnitude lower than the moment for a shell magnetized in an external uniform field and is of the same order as the upper limit of the residual moment detected by Russellet al. (1974). At present the magnetic data and the thermal state of the Moon are not known with sufficient accuracy to distinguish between a crust magnetized in an internal dipole field of constant polarity and a crust magnetized in the dipole field of a self-reversing core dynamo. Refined measurements of the relevant parameters together with the theory presented in this paper could enable these two possibilities to be distinguished.
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Dyal, P., Parkin, C. W., and Daily, W. D.: 1973,Proc. 4th Lunar Sci. Conf., Geochim. Cosmochim. Acta, Suppl. 4,3, 2925–2945.
Dyal, P., Parkin, C. W., and Daily, W. D.: 1975,Proc. 6th Lunar Sci. Conf., Geochim. Cosmochim. Acta., in press.
Huffman, G. P., Schwerer, F. C., Fisher, R. M., and Nagata, T.: 1974,Proc. 5th Lunar Sci. Conf., Suppl. 5, 2779–2794.
Parkin, C. W., Daily, W. D., and Dyal, P.: 1974,Proc. 5th Lunar Sci. Conf., Geochim. Cosmochim. Acta, Suppl. 5,3, 2761–2778.
Pearce, G. W., Gose, W. A., and Strangway, D. W.: 1973,Proc. 4th Lunar Sci. Conf., Geochim. Cosmochim. Acta, Suppl. 4,3, 3045–3076.
Pearce, G. W., Williams, R. J., and McKay, D. S.: 1972,Earth Planetary Sci. Letters 17, 95–104.
Runcorn, S. K.: 1975,Nature 253, 701–703.
Runcorn, S. K. and Urey, H. C.: 1973,Science 180, 636–638.
Runcorn, S. K., Collinson, D. W., O'Reilly, W., Battey, M. H., Stephenson, A., Jones, J. M., Manson, A. J., and Readman, P. W.: 1970,Proc. Apollo 11 Lunar Sci. Conf. 3, 2369–2387, Pergamon Press.
Russell, C. T., Coleman, P. J., Lichtenstein, B. R., and Schubert, G.: 1974,Proc. 5th Lunar Sci. Conf., Geochim. Cosmochim. Acta, Suppl. 5,3, 2747–2760.
Stephenson, A.: 1975,Geophys. J. Roy. Astron Soc. 40, 29–36.
Stephenson, A., Runcorn, S. K., and Collinson, D. W.: 1975,Proc. 6th Lunar Sci. Conf., Geochim. Cosmochim. Acta, in press.
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Stephenson, A. The residual permanent magnetic dipole moment of the moon. The Moon 15, 67–81 (1976). https://doi.org/10.1007/BF00562472
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DOI: https://doi.org/10.1007/BF00562472