Tidal heating in an internal ocean model of Europa (original) (raw)

Nature volume 325, pages 133–134 (1987)Cite this article

Abstract

Considerable evidence suggests that Europe's internal structure might consist of a liquid water layer that decouples a thin (<30 km) overlying ice lithosphere from an underlying silicate core1,2. A lack of impact features, extremely subdued topography, and positive spectroscopic identification of H2O all imply recent resurfacing by water. In addition, curvilinear features resembling cracks are ubiquitous over the surface; their orientations are broadly consistent with tidally controlled tectonic activity3. Compositional models of Europea indicate that the H2O layer could be over 100 km thick1. Cassen et al.4 first showed how tidal heating, if sufficiently intense, might stabilize a thin (<30 km) ice lithosphere over the internal ocean and prevent the water from freezing. Other models of Europa do not include an internal ocean and instead have an ice layer (perhaps as thick as 100 km or as thin as a few kilometres) resting directly on the silicate interior5,6. However, based on studies of crater relaxation, Thomas and Schubert7 have shown the version of this model with a thin ice layer to be unlikely. The plausibility of the internal ocean model vis-a-vis the thick ice model depends critically on the level of tidal heating in Europa. Here we present new calculations of tidal heating based on a more realistic three-layer model of Europa. The tidal distortion of a decoupled ice lithosphere is only half that previously thought. At the current value of orbital eccentricity, tidal heating is only marginally able to prevent the internal ocean from freezing.

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

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

Additional access options:

Similar content being viewed by others

References

  1. Cassen, P., Peale, S. J. & Reynolds, R. T. in Satellites of Jupiter (ed. Morrison, D.) 93–128 (University of Arizona Press, Tucson, 1982).
    Google Scholar
  2. Schubert, G., Reynolds, R. T. & Spohn, T. in Satellites (eds Burns, J. A. & Matthews, M. S.) 224–292 (University of Arizona Press, Tucson, 1986).
    Google Scholar
  3. Helfenstein, P. & Parmentier, E. M. in Proc. 11th lunar and planet. Sci. Conf., 1987–1998 (1980).
  4. Cassen, P., Reynolds, R. T. & Peale, S. J. Geophys. Res. Lett. 6, 731–734 (1979).
    Article ADS Google Scholar
  5. Ransford, G. A., Finnerty, A. A. & Collerson, K. D. Nature 289, 21–24 (1981).
    Article ADS CAS Google Scholar
  6. Finnerty, A. A., Ransford, G. A., Pieri, D. & Collerson, K. D. Nature 289, 24–27 (1980).
    Article ADS Google Scholar
  7. Thomas, P. & Schubert, G. J. geophys. Res. 91, D453–D459 (1986).
    Article ADS Google Scholar
  8. Cassen, P., Reynolds, R. T. & Peale, S. J. Geophys. Res. Lett. 7, 987–988 (1980).
    Article ADS Google Scholar
  9. Squyres, S. W., Reynolds, R. T., Cassen, P. & Peale, S. J. Nature 301, 225–226 (1983).
    Article ADS CAS Google Scholar
  10. Cappallo, R. J., Counselman, C. C., King, R. W. & Shapiro, I. I. J. geophys. Res. 86, 7180–7184 (1981).
    Article ADS Google Scholar
  11. Yoder, C. F. Phil. Trans. R. Soc. 303, 327–338 (1981).
    Article ADS Google Scholar
  12. Peale, S. J. & Cassen, P. Icarus 36, 245–269 (1978).
    Article ADS Google Scholar
  13. Sabadini, R., Yuen, D. A. & Boschi, E. J. geophys. Res. 87, 2885–2903 (1982).
    Article ADS Google Scholar
  14. Crossley, D. J. & Gubbins, D. Geophys. Res. Lett. 2, 1–5 (1975).
    Article ADS Google Scholar
  15. Kaula, W. M. Rev. Geophys. 2, 661–685 (1964).
    Article ADS Google Scholar
  16. Shoemaker, E. M., Lucchita, B. K., Plescia, J. B., Squyres, S. W. & Wilhelms, D. E. in Satellites of Jupiter (ed. Morrison, D.) 435–520 (University of Arizona Press, Tucson, 1982).
    Google Scholar
  17. Passey, Q. Icarus 53, 105–120 (1983).
    Article ADS Google Scholar
  18. Buratti, B. J. Icarus 61, 208–217 (1985).
    Article ADS Google Scholar
  19. Murase, T. & McBirney, A. R. Bull. geol. Soc. Am. 84, 3563–3592 (1973).
    Article CAS Google Scholar
  20. Glen, J. W. Cold Regions Science & Engineering Monograph (US Army, Hanover, New Hampshire, 1975).
    Google Scholar
  21. Greenberg, R. & Weidenschilling, S. J. Icarus 58, 186–196.

Download references

Author information

Authors and Affiliations

  1. Department of Earth and Space Sciences, University of California, Los Angeles, California, 90024, USA
    M. N. Ross & G. Schubert

Authors

  1. M. N. Ross
    You can also search for this author inPubMed Google Scholar
  2. G. Schubert
    You can also search for this author inPubMed Google Scholar

Rights and permissions

About this article

Cite this article

Ross, M., Schubert, G. Tidal heating in an internal ocean model of Europa.Nature 325, 133–134 (1987). https://doi.org/10.1038/325133a0

Download citation

This article is cited by

Comments

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.