Numerical simulations of thermal-chemical instabilities at the core–mantle boundary (original) (raw)

Nature volume 334, pages 237–240 (1988) Cite this article

Abstract

Dynamical effects at the core–mantle boundary have so far been modelled mainly with thermal convection1,2, yet accumulating evidence3,4 supports the idea of a combined thermal and chemical boundary layer as the likely explanation of the D″ zone. Here we present numerical simulations of thermal-chemical instabilities in the D″ layer which show that strong lateral heterogeneities in the composition and density fields can be initiated and maintained dynamically if there is continuous replenishment of material from subduced slabs coming from the upper mantle. These chemical instabilities have a tendency to migrate laterally and may help to support core–mantle boundary topography with short and long wavelengths. The thermal-chemical flows produce a relatively stagnant D″ layer with strong lateral and temporal variations in basal heat flux, which gives rise to thermal core–mantle interactions5, influencing the geodynamo.

This is a preview of subscription content, access via your institution

Access options

Subscribe to this journal

Receive 51 print issues and online access

$199.00 per year

only $3.90 per issue

Buy this article

USD 39.95

Prices may be subject to local taxes which are calculated during checkout

Additional access options:

Similar content being viewed by others

References

  1. Hager, B. H., Clayton, R. W., Richards, M. A., Comer, R. P. & Dziewonski, A. M. Nature 313, 541–545 (1985).
    Article ADS Google Scholar
  2. Zhang, S. & Yuen, D. A. Geophys. Res. Lett. 14, 899–902 (1987).
    Article ADS Google Scholar
  3. Young, C. J. & Lay, T. A. Rev. Earth, planet. Sci. 15, 25–46 (1987).
    Article ADS CAS Google Scholar
  4. Creager, K. C. & Jordan, T. H. Geophys. Res. Lett. 13, 1497–1500 (1986).
    Article ADS Google Scholar
  5. Bloxham, J. & Gubbins, D. Nature 325, 511–513 (1987).
    Article ADS Google Scholar
  6. Morclli, A. & Dziewonski, A. M. Nature 325, 678–683 (1987).
    Article ADS Google Scholar
  7. Olson, P., Schubert, G. & Anderson, C. Nature 327, 409–413 (1987).
    Article ADS Google Scholar
  8. Davies, G. F. & Gurnis, M. Geophys. Res. Lett. 13, 1517–1520 (1986).
    Article ADS Google Scholar
  9. Anderson, D. L. Phys. Earth planet. Inter. 45, 307–323 (1987).
    Article ADS CAS Google Scholar
  10. Brown, J. M. Geophys. Res. Lett. 13, 1509–1512 (1986).
    Article ADS Google Scholar
  11. Zhang, S. & Yuen, D. A. Geophys. Res. Lett. 15, 451–454 (1988).
    Article ADS Google Scholar
  12. Hofmann, A. W. & White, W. M. Earth planet. Sci. Lett. 57, 421–436 (1982).
    Article ADS CAS Google Scholar
  13. Christensen, U. R. EOS 68, 1488 (1987).
    Article Google Scholar
  14. Hansen, U. & Yuen, D. A. Geophys. Res. Lett. 14, 1099–1102 (1987).
    Article ADS Google Scholar
  15. Hansen, U. & Ebel, A. Geophys. J. 194, 181–191 (1988).
    Article Google Scholar
  16. Williams, Q., Jeanloz, R., Bass, J., Svendsen, B. & Ahrens, T. J. Science 236, 181–182 (1987).
    Article ADS CAS Google Scholar
  17. McKenzie, D. P. J. Petrology 25, 713–765 (1984).
    Article ADS CAS Google Scholar

Download references

Author information

Authors and Affiliations

  1. Institut für Geophysik und Meteorologie, Universität zu Köln, D-5000, Köln, 41, FRG
    Ulrich Hansen
  2. Minnesota Supercomputer Institute and Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota, 55455, USA
    David A. Yuen

Authors

  1. Ulrich Hansen
  2. David A. Yuen

Rights and permissions

About this article

Cite this article

Hansen, U., Yuen, D. Numerical simulations of thermal-chemical instabilities at the core–mantle boundary.Nature 334, 237–240 (1988). https://doi.org/10.1038/334237a0

Download citation

This article is cited by