Does the whole of the Earth's core convect? (original) (raw)

Nature volume 287, pages 528–530 (1980) Cite this article

Abstract

Higgins and Kennedy1 used data on the behaviour of iron at high temperatures and pressures to infer that the top of the Earth's liquid core is stably stratified. Attempts to confirm this result both thermodynamically2 and using seismological data3 have been inconclusive. I present here geomagnetic results which may resolve the controversy. If a stratified region exists there will be no upwelling or downwelling of core fluid at the core–mantle boundary (CMB), so there will be no horizontal divergence of velocity v, that is ▿H·v = 0, where ▿H = ▿ − r̂(r̂·▿) r̂ denotes the unit radial vector. This hypothesis can be tested directly, using geomagnetic data, at a few isolated points on the CMB, and local averages of ▿H·v can be examined over the rest of the surface. A statistical treatment of the results strongly suggests that ▿H·v = 0, which is a consequence of a stably stratified layer.

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References

  1. Higgins, G. & Kennedy, G. C. J. geophys. Res. 76, 1870–1878 (1971).
    Article ADS Google Scholar
  2. Boehler, Reinhard & Kennedy, G. C. J. appl. Phys. 48, 4183–4186 (1977).
    Article ADS CAS Google Scholar
  3. Masters, G. Geophys. J. R. astr. Soc. 57, 507–534 (1979).
    Article ADS CAS Google Scholar
  4. Roberts, P. H. & Scott, S. J. Geomagn. Geoelect. 17, 137–151 (1965).
    Article ADS Google Scholar
  5. Backus, G. E. Phil. Trans. R. Soc. A263, 239–266 (1968).
    Article ADS Google Scholar
  6. Zmuda, A. J. IAGA Bull. No. 28 (1971).
  7. Whaler, K. A. & Gubbins, D. Geophys. J. R. astr. Soc. (in the press).
  8. Benton, E. R. & Muth, L. A. Phys. Earth planet. Interiors 20, 127–133 (1979).
    Article ADS Google Scholar
  9. Benton, E. R. Phys. Earth planet. Interiors (in the press).

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Authors and Affiliations

  1. Bullard Laboratories, Department of earth Sciences, University of Cambridge, Madingley Road, Cambridge, CB3 0EZ, UK
    K. A. Whaler

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Whaler, K. Does the whole of the Earth's core convect?.Nature 287, 528–530 (1980). https://doi.org/10.1038/287528a0

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