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On the characteristics of successive geomagnetic jerks

Abstract

Spherical harmonic models of the 1969, 1979 and 1992 geomagnetic jerks are computed using data from about 160 worldwide geomagnetic observatories. The dominance of the internal origin part with respect to the external one confirms again the internal origin of these events. A change of sign is observed between two successive jerks (1969–1979, 1979–1992). The acceleration jump of the fluid flow at the core mantle boundary (CMB) generating the three jerks is computed. Striking similarities between the three acceleration maps are observed (within the sign change mentioned above). These results suggest some long time scale memory in the processes that are responsible for the jerks. These processes remain to be elucidated.

References

  1. Alexandrescu, M., Le champ géomagnétique et ses observatoires, Thèse, Institut de Physique du Globe de Paris, 271 pp., 1996.

  2. Alexandrescu, M., D. Gibert, G. Hulot, J.-L. Le Mouël, and G. Saracco, Detections of geomagnetic jerks using wavelet analysis, J. Geophys. Res., 100, B7, 12557–12572, 1995.

    Article  Google Scholar 

  3. Alexandrescu, M., D. Gibert, G. Hulot, J.-L. Le Mouël, and G. Saracco, Worldwide wavelet analysis of geomagnetic jerks, J. Geophys. Res., 101, B10, 21975–21994, 1996.

    Article  Google Scholar 

  4. Alldredge, L. R., A hypothesis for the source of impulses in geomagnetic secular variations, J. Geophys. Res., 80, 11, 1571–1578, 1975.

    Article  Google Scholar 

  5. Alldredge, L. R., A discussion of impulses and jerks in the geomagnetic field, J. Geophys. Res., 89, 4403–4412, 1984.

    Article  Google Scholar 

  6. Backus, G. E., Kinematics of geomagnetic secular variation in a perfectly conducting core, Philos. Trans. R. Soc. Lond., Se. A, 263, 239–266, 1968.

    Article  Google Scholar 

  7. Backus, G. E. and J.-L Le Mouël, The region of the core-mantle boundary where a geostrophic velocity fields can be determined from frozen-flux magnetic data, Geophys. J. R. Astron. Soc, 85, 617–628, 1986.

    Google Scholar 

  8. Bloxham, J., Simple models of fluid flow at the core surface derived from geomagnetic field models, Geophys. J. R. Astron. Soc., 99, 173–182, 1989.

    Article  Google Scholar 

  9. Bloxham, J. and A. Jackson, Time-dependent mapping of the magnetic field at the core-mantle boundary, J. Geophys. Res., 97, 19537–19564, 1992.

    Article  Google Scholar 

  10. Chau, H. D., J. Ducruix, and J.-L Le Mouël, Sur le caractère planétaire du saut de variation séculaire de 1969–1970, C. R. Acad. Sci. Paris, 293, Série B, 157–160, 1981.

    Google Scholar 

  11. Courtillot, V. and J.-L. Le Mouël, On the long-period variations of the Earth’s magnetic field from 2 months to 20 years, J. Geophys. Res., 81, 2941–2950, 1976.

    Article  Google Scholar 

  12. Courtillot, V. and J.-L. Le Mouël, Geomagnetic secular variation impulses, Nature, 311, 709–716, 1984.

    Article  Google Scholar 

  13. Courtillot, V., J. Ducruix, and J.-L. Le Mouël, Sur une accélération récente de la variation séculaire du champ magnétique terrestre, C. R. Acad. Sci. Paris, 287, Série D, 1095–1098, 1978.

    Google Scholar 

  14. Currie, R. G., Geomagnetic spectrum of internal origin and lower mantle conductivity, J. Geophys. Res., 73, 2779–2786, 1968.

    Article  Google Scholar 

  15. De Michelis, P., L. Cafarella, and A. Meloni, Worldwide character of the 1991 jerk, Geophys. Res. Lett., 25, 377–380, 1998.

    Article  Google Scholar 

  16. Gavoret, J., D. Gibert, M. Menvielle, and J.-L Le Mouël, Long-term variations of the external and internal components of the Earth’s magnetic field, J. Geophys. Res.,91, B5, 4787–4796, 1986.

    Article  Google Scholar 

  17. Gire, C. and J.-L. Le Mouël, Tangentially geostrophic flow at the core-mantle boundary compatible with the observed geomagnetic secular variation: the large-scale component of the flow, Phys. Earth Planet. Inter., 59, 259–287, 1990.

    Article  Google Scholar 

  18. Gire, C., J.-L. Le Mouël, and T. Madden, Motions at the core surface derived from SV data, Geophys. J. R. Astron. Soc., 84, 1–29, 1986.

    Article  Google Scholar 

  19. Golovkov, V. P., T. I. Zvereva, and A. O. Simonyan, Common features and differences between “jerks” of 1947, 1958 and 1969, Geophys. Astrophys. Fluid Dyn., 49, 81–96, 1989.

    Article  Google Scholar 

  20. Gubbins, D., Geomagnetic field analysis, II, Secular variation consistent with a perfectly conducting core, Geophys. J. R. Astron. Soc., 77, 753–766, 1984.

    Article  Google Scholar 

  21. Gubbins, D. and P. H. Roberts, Magnetohydrodynamics of the Earth’s core, in Geomagnetism 2, edited by J. A. Jacobs, pp. 1–183, Academic Press, London, 1987.

    Google Scholar 

  22. Gubbins, D. and L. Tomlinson, Secular variation from monthly means from Apia and Amberley magnetic observatories, Geophys. J. R. Astron. Soc., 86, 603–616, 1986.

    Article  Google Scholar 

  23. Hulot, G., J.-L. Le Mouël, and J. Wahr, Taking into account truncation problems and geomagnetic model accuracy in assessing computed flows at the core-mantle boundary, Geophys. J. Int..108, 224–246, 1992.

    Article  Google Scholar 

  24. Hulot, G., M. Le Huy, and J.-L. Le Mouël, Secousses (jerks) de la variation séculaire et mouvements dans le noyau terrestre, C. R. Acad. Sci. Paris, 317, Série II, 333–341, 1993.

    Google Scholar 

  25. Kerridge, D. J. and D. R. Barraclough, Evidence for geomagnetic jerks from 1931 to 1971, Phys. Earth Planet. Inter., 39, 228–236, 1985.

    Article  Google Scholar 

  26. Le Huy, M., Le champ géomagnétique, les mouvements du fluide à la surface du noyau et les variations décennales de la rotation de la Terre, Thèse, Université de Paris VII, 274 pp., 1995.

  27. Le Mouël, J.-L., Outer-core geostrophic flow and secular variation of Earth’s geomagnetic field, Nature, 311, 734–735, 1984.

    Article  Google Scholar 

  28. Le Mouël, J.-L., J. Ducruix, and C. Ha Duyen, The worldwide character of the 1969–1970 impulse of the secular acceleration rate, Phys. Earth Planet. Inter., 28, 337–350, 1982.

    Article  Google Scholar 

  29. Lowes, F. J., Mean square values on the sphere of spherical harmonic vector fields, J. Geophys. Res., 71, 2179, 1966.

    Article  Google Scholar 

  30. Macmillan, S., A geomagnetic jerk for the early 1990’s, Earth Planet. Sci. Lett., 137, 189–192, 1996.

    Article  Google Scholar 

  31. Madden, T. and J.-L. Le Mouël, The recent secular variation and the motions at the core surface, Philos. Trans. R. Soc. Lond., A306, 271–280, 1982.

    Article  Google Scholar 

  32. Malin, S. R. C. and B. M. Hodder, Was the 1970 geomagnetic jerk of internal or external origin?, Nature, 296, 726–728, 1982.

    Article  Google Scholar 

  33. Malin, S. R. C., B. M. Hodder, and D. R. Barraclough, Geomagnetic variation: a jerk in 1970, in 75th Anniversary Volume of Ebro Observatory, edited by J. O. Cardus, pp. 239–256, Ebro Obs., Tarragona, Spain, 1983.

    Google Scholar 

  34. McLeod, M. G., On the geomagnetic jerk of 1969, J. Geophys. Res., 90, 4597–4610, 1985.

    Article  Google Scholar 

  35. McLeod, M. G., Signals and noise in magnetic observatory annual means. Mantle conductivity and jerks, J. Geophys. Res., 97, 17261–17290, 1992.

    Article  Google Scholar 

  36. Roberts, P. H. and S. Scott, On the analysis of the secular variation. 1. A hydromagnetic constraint: theory, J. Geomag. Geoelectr., 17, 137–151, 1965.

    Article  Google Scholar 

  37. Shapiro, V. A. and A. A. Akhmetzanova, Jerks in the thin structure of the geomagnetic secular variations in the course of 21st and 22nd solar cycles: their signature and origin, Abstracts 8th Assembly of IAGA, session 1.02, Uppsala, 1997.

  38. Stewart, D. N., Geomagnetic impulses and the electrical conductivity of the lower mantle, Ph.D. Thesis, The University of Leeds, Department of Earth Sciences, 191 pp., 1991.

  39. Stewart, D. N. and K. Whaler, Geomagnetic disturbance fields: An analysis of observatory monthly means, Geophys. J. Int., 108, 215–223, 1992.

    Article  Google Scholar 

  40. Whaler, K. A., A new method for analysing geomagnetic impulses, Phys. Earth Planet. Inter., 48, 221–240, 1987.

    Article  Google Scholar 

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Correspondence to Minh Le Huy.

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Le Huy, M., Alexandrescu, M., Hulot, G. et al. On the characteristics of successive geomagnetic jerks. Earth Planet Sp 50, 723–732 (1998). https://doi.org/10.1186/BF03352165

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Keywords

  • Secular Variation
  • Core Mantle Boundary
  • Magnetic Observatory
  • Geomagnetic Observatory
  • Spherical Harmonic Analysis