Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Periodicity of the Earth's magnetic reversals


Reversals of the Earth's magnetic field may occur with a certain regularity. Using observed percentages of normal and reversed polarity during different time intervals, Negi and Tiwari1 detected several significant periodicities, notably one of 32–34 Myr. Raup2 used the dates of individual reversals to propose a 30-Myr period in the frequency of reversals, although Mazaud et al.3 obtained a periodicity of only 15 Myr. Like Negi and Tiwari's1 other detected short periods, the 15-Myr period may be harmonically related to a basic 30-Myr period4. It has also been suggested that these are accidental periodicities arising in a short record5,6, or are harmonics of the record length itself7. In fact, all of the cited studies have used different data, different record lengths and different methods of time-series analysis. Raup8 has consequently retracted his original claim. Here I present a much fuller analyis of the reversal record and show that a statistically significant period of 30 Myr does formally exist, in spite of the cited differences.

This is a preview of subscription content

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. Negi, J. G. & Tiwari, R. K. Geophys. Res. Lett. 10, 713–716 (1983).

    ADS  Article  Google Scholar 

  2. Raup, D. M. Nature 314, 341–343 (1985).

    ADS  CAS  Article  Google Scholar 

  3. Mazaud, A., Laj, C., de Séze, L. & Verosub, K. L. Nature 304, 328–330 (1983).

    ADS  Article  Google Scholar 

  4. Rampino, M. R. & Stothers, R. B. Science 226, 1427–1431 (1984).

    ADS  CAS  Article  Google Scholar 

  5. McFadden, P. L. Nature 311, 396 (1984).

    ADS  Article  Google Scholar 

  6. Mazaud, A., Laj, C., de Séze, L. & Verosub, K. L. Nature 311, 396 (1984).

    Article  Google Scholar 

  7. Lutz, T. M. Nature 317, 404–407 (1985).

    ADS  Article  Google Scholar 

  8. Raup, D. M. Nature 317, 384–385 (1985).

    ADS  Article  Google Scholar 

  9. Harland, W. B. et al. A Geological Time Scale (Cambridge University Press, 1982).

    Google Scholar 

  10. Lowrie, W. & Kent, D.V. Earth planet. Sci. Lett. 62, 305–313 (1983).

    ADS  Article  Google Scholar 

  11. Stothers, R. Astr. Astrophys. 77, 121–127 (1979).

    ADS  Google Scholar 

  12. Raup, D. M. & Sepkoski, J. J. Proc. natn. Acad. Sci. U.S.A. 81, 801–805 (1984).

    ADS  CAS  Article  Google Scholar 

  13. Fraser, D. A. S. Statistics: An Introduction, 245 (Wiley, New York, 1958).

    Book  Google Scholar 

  14. Broadbent, S. R. Biometrika 42, 45–57 (1955); 43, 32–44 (1956).

    MathSciNet  Article  Google Scholar 

  15. Kent, D. V. & Gradstein, F. M. in The Western Atlantic Region, Volume M of the Geology of North America (eds Tucholke, B. E. & Vogt, P. R.) (Geological Society of America, Boulder, in the press).

  16. Lowrie, W. & Alvarez, W. Geology 9, 392–397 (1981).

    ADS  Article  Google Scholar 

  17. Pal, P. C. & Creer, K. M. Nature 320, 148–150 (1986).

    ADS  Article  Google Scholar 

  18. Shuter, W. L. H. & Klatt, C. Astrophys. J. 301, 471–477 (1986).

    ADS  Article  Google Scholar 

  19. Rampino, M. R. & Stothers, R. B. Nature 308, 709–712 (1984).

    ADS  Article  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

Stothers, R. Periodicity of the Earth's magnetic reversals. Nature 322, 444–446 (1986).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing