Skip to main content

Volume 56 Supplement 2

Special Issue: Special section for IUGG workshop: Lithospheric Structure of a Supercontinent:Gondwana

Genetic Algorithm inversion of geomagnetic vector data using a 2.5-dimensional magnetic structure model

Abstract

We propose a new inversion method for vector magnetic field data, which uses the Genetic Algorithm in a space domain calculation to determine the best-fitting 2.5-dimensional (2.5-D) structure. This 2.5-D model is composed of magnetic boundaries with arbitrary strike and magnetic intensity. Two numerical formulas combine to express this model. One of them is a two-dimensional magnetic structure expression for a realistically shaped magnetic layer, and the other is a magnetization contrast expression for magnetic boundaries of variable strike. We use a Genetic Algorithm as the computational technique that supports optimum solutions for magnetization, magnetic strike, and boundary location. In practice, calculations are more accurate in the space domain instead of the more conventional frequency domain because it better preserves the short wavelength components and the true geometry between magnetic sources and observation points even for uneven survey track lines. The above leads to high resolution in the inferred magnetization without the need of upward continuation, which is particularly useful for inverting near-bottom survey data. The code is designed to use smaller storage and less computational time. Its application to synthetic data illustrates the power of resolution and precision in interpreting the fine scale processes of mid-ocean ridge accretion.

References

  • Blakely, R. J., Magnetic models, in Potential Theory in Gravity and Magnetic Applications, pp. 195–213, Cambridge Univ. Press., US, 1995.

    Chapter  Google Scholar 

  • Carbotte, S. M., J. C. Mutter, and L. Xu, Contribution of volcanism and tectonism to axial and flank morphology of the southern East Pacific Rise, 17°10’-17°40’S, from a study of layer 2A geometry, J. Geophys. Res., 102, 10165–10184, 1997.

    Article  Google Scholar 

  • Goldberg, D. E., Genetic Algorithms in search, optimization and machine learning, Addison-Wesley, US, 1989.

    Google Scholar 

  • Hussenoeder, S. A., M. A. Tivey, and H. Shouten, Direct inversion of potential field from an uneven track with application to the Mid-Atlantic Ridge, Geophys. Res. Lett., 22, 3131–3134, 1995.

    Article  Google Scholar 

  • Isezaki, N., A new shipboard three-component magntometer, Geophysics, 51, 1992–1998, 1986.

    Article  Google Scholar 

  • Macdonald, K. C, S. P. Miller, S. P. Huestis, and F. N. Spiess, Three-dimensional modeling of a magnetic reversal boundary from inversion of deep-tow measurements, J. Geophys. Res., 85, 3670–3680, 1980.

    Article  Google Scholar 

  • Mcdonald, K. C, S. P. Miller, B. P. Luyendyk, and T. M. Atwater, Investigation of a Vine-Mattews magnetic lineation from a submersible: the source and character of marine magnetic anomalies, J. Geophys. Res., 88, 3403–3418, 1983.

    Article  Google Scholar 

  • Morley, L. W. and A. Larochelle, Paleomagnetism as a means of dating geological events, in Geochronology in Canada, pp. 39–51, Univ. of Toronto Press., Toronto, 1964.

    Google Scholar 

  • Parker, R. L., The rapid calculation of potential anomalies, J. Astron. Soc, 31, 447–455, 1972.

    Article  Google Scholar 

  • Parker, R. L. and S. P. Huestis, The inversion of magnetic anomalies in the presence of topography, J. Geophys. Res., 79, 1587–1593, 1974.

    Article  Google Scholar 

  • Schouten, H., M. A. Tivey, D. J. Fornari, and J. R. Cochran, Central anomaly magnetization high: constraints on the volcanic construction and architecture of seismic layer 2A at a fast-spreading mid-ocean ridge, the EPR at 9°30’-50’N, Earth Planet. Sci. Lett., 169, 37–50, 1999.

    Article  Google Scholar 

  • Seama, N., Y. Nogi, and N. Isezaki, A new method for precise determination of the position and strike of magnetic boundaries using vector data of the geomagnetic anomaly field, Geophys. J. Int., 113, 115–164, 1993.

    Article  Google Scholar 

  • Seama, N., M. Yamamoto, and N. Isezaki, A newly developed deep-tow three component magnetometer, Eos Trans., AGU, 78(46) Fall Mett., Suppl. 192, 1997.

    Google Scholar 

  • Vacquier, V., The physics of geomagnetism, in Geomagnetism in Marine Geology, pp. 1–9, Elsevier, Amsterdam, 1972.

    Google Scholar 

  • Vine, F J. and D. H. Matthews, Magnetic anomalies over ocean ridges, Nature, 199, 947–949, 1963.

    Article  Google Scholar 

  • Yamamoto, M., N. Seama, and N. Isezaki, Deep-tow vector geomagnetic survey at East Pacific Rise, 18°S, Eos Trans., AGU, 80(46), Fall Mett., Suppl. 1075, 1998.

    Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Michiko Yamamoto.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Yamamoto, M., Seama, N. Genetic Algorithm inversion of geomagnetic vector data using a 2.5-dimensional magnetic structure model. Earth Planet Sp 56, 217–227 (2004). https://doi.org/10.1186/BF03353404

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03353404

Key words

  • Genetic Algorithm
  • geomagnetic vector data
  • near-bottom survey
  • 2.5 D magnetic structure