Evidence from the Mars Express High Resolution Stereo Camera for a frozen sea close to Mars' equator


It is thought that the Cerberus Fossae fissures on Mars were the source of both lava and water floods1,2,3,4 two to ten million years ago1,2,5. Evidence for the resulting lava plains has been identified in eastern Elysium1,2,4,6,7,8, but seas and lakes from these fissures and previous water flooding events were presumed to have evaporated and sublimed away9,10,11. Here we present High Resolution Stereo Camera images from the European Space Agency Mars Express spacecraft that indicate that such lakes may still exist. We infer that the evidence is consistent with a frozen body of water, with surface pack-ice, around 5° north latitude and 150° east longitude in southern Elysium. The frozen lake measures about 800 × 900 km in lateral extent and may be up to 45 metres deep—similar in size and depth to the North Sea. From crater counts, we determined its age to be 5 ± 2 million years old. If our interpretation is confirmed, this is a place that might preserve evidence of primitive life, if it has ever developed on Mars.

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Figure 1: Views of plate-like terrain on Mars, and pack-ice on Earth.
Figure 2: Pressure ridges on Mars, and those caused on Earth by pack-ice drift against obstacles.
Figure 3: Age dating by crater counting12,13 on the pack-ice surface using HRSC (triangles) and MOC imagery over a total area of 380 km2 (squares and diamonds), including those craters that protrude through the surface from the substratum (circles).
Figure 4: Evidence of ice surface lowering and draping of plate-like features over partly submerged impact craters.


  1. 1

    Berman, D. C. & Hartmann, W. K. Recent fluvial, volcanic and tectonic activity on the Cerberus Plains of Mars. Icarus 159, 1–17 (2002)

    ADS  Article  Google Scholar 

  2. 2

    Burr, D. M., Grier, J. A., McEwen, A. S. & Keszthleyi, L. P. Repeated aqueous flooding from the Cerberus Fossae: Evidence for very recently extant, deep groundwater on Mars. Icarus 159, 53–73 (2002)

    ADS  Article  Google Scholar 

  3. 3

    Head, J. W. III, Wilson, L. & Mitchell, K. L. Generation of recent massive water floods at Cerberus Fossae, Mars, by dike emplacement, cryospheric cracking, and confined aquifer groundwater release. Geophys. Res. Lett. 30, 1577, doi:10.1029/2003GL017135 (2003)

    ADS  Article  Google Scholar 

  4. 4

    Plescia, J. B. Cerberus Fossae, Elysium, Mars: a source for lava and water. Icarus 164, 79–95 (2003)

    ADS  Article  Google Scholar 

  5. 5

    Werner, S. C., van Gasselt, S. & Neukum, G. Continual geological activity in Athabasca Valles Mars. J. Geophys. Res. 108, E12, 8081, doi:10. 1029/2002JE002020 (2003)

    Article  Google Scholar 

  6. 6

    Keszthelyi, L., McEwen, A. S. & Thordarson, T. Terrestrial analogs and thermal models for Martian flood lavas. J. Geophys. Res. 105, 15027–15049 (2000)

    ADS  Article  Google Scholar 

  7. 7

    Fuller, E. R. & Head, J. W. III Amazonis Planitia: the role of geologically recent volcanism and sedimentation in the formation of the smoothest plains on Mars. J. Geophys. Res. 107, 5081, doi:10.1029/2002JE001842 (2002)

    Article  Google Scholar 

  8. 8

    Lanagan, P. D. & McEwen, A. S. Cerberus Plains volcanism: constraints on temporal emplacement of the youngest flood lavas on Mars. 6th Int. Conf. on Mars abstr. 3215 (2003); http://www.lpi.usra.edu/meetings/sixthmars2003/pdf/3215.pdf.

  9. 9

    Carr, M. H. Stability of Martian streams and lakes. Icarus 56, 476–495 (1983)

    ADS  Article  Google Scholar 

  10. 10

    Kreslavsky, M. A. & Head, J. W. III Fate of outflow channel effluents in the northern lowlands of Mars: the Vastitas Borealis formation as a sublimation residue from frozen ponded bodies of water. J. Geophys. Res. 107, 5121, doi:10.1029/2001JE001831 (2001)

    Google Scholar 

  11. 11

    Carr, M. H. & Head, J. W. III Oceans on Mars: an assessment of the observational evidence and possible fate. J. Geophys. Res. 108, 5042, doi:10.1029/2002JE001963 (2003)

    Article  Google Scholar 

  12. 12

    Hartmann, W. K. & Neukum, G. Cratering chronology and the evolution of Mars. Space Sci. Rev. 96, 165–194 (2001)

    ADS  Article  Google Scholar 

  13. 13

    Neukum, G. et al. Recent and episodic volcanic and glacial activity on Mars revealed by the High Resolution Stereo Camera. Nature 432, 971–979 (2004)

    ADS  CAS  Article  Google Scholar 

  14. 14

    Patrick, M. R., Dehn, J. & Dean, K. Numerical modelling of lava flow cooling applied to the 1997 Okmok eruption: approach and analysis. J. Geophys. Res. 109, B03202, doi:10.1029/2003JB002537 (2004)

    ADS  Article  Google Scholar 

  15. 15

    Skinner, B. J. Thermal expansion. In Handbook Of Physical Constants (ed. Clark, S. P.) Geol. Soc. Am. Mem. 97, 75–96 (1966).

  16. 16

    Garvin, J. B., Sakimoto S. E. H. & Frawley, J. J. Craters on Mars: global geometric properties from gridded MOLA topography. Sixth Int. Conf. on Mars abstr. 3277 (2003); http://www.lpi.usra.edu/meetings/sixthmars2003/pdf/3277.pdf.

  17. 17

    Rice, J. W., Parker, T. J., Russel, A. J. & Knudsen, O. Morphology of fresh outflow channel deposits on Mars. Lunar Planet. Sci. XXXIII abstr. 2026 [CD-Rom] (Lunar & Planetary Institute, Houston, Texas, 2002).

  18. 18

    Baker, V. R. et al. in Mars (eds Kieffer, H. H., Jakosky, B. M., Snyder, C. W. & Matthews, M. S.) 493–522 (Univ. Arizona Press, Tucson, 1992)

    Google Scholar 

  19. 19

    Wallace, D. & Sagan, C. Evaporation of ice in planetary atmospheres: ice-covered rivers on Mars. Icarus 39, 476–495 (1983)

    Google Scholar 

  20. 20

    Clifford, S. M. A model for the hydrologic and climatic behavior of water on Mars. J. Geophys. Res. 98, 10973–11016 (1993)

    ADS  CAS  Article  Google Scholar 

  21. 21

    Clifford, S. M. & Parker, T. J. The evolution of the Martian hydrosphere: implications for the fate of a primordial ocean and the current state of the northern plains. Icarus 154, 40–79 (2001)

    ADS  CAS  Article  Google Scholar 

  22. 22

    Carr, M. H. D/H on Mars: effects of floods, volcanism, impacts and polar processes. Icarus 87, 210–227 (1990)

    ADS  Article  Google Scholar 

  23. 23

    Skorov, Y. V., Markiewicz, W. J., Basilevsky, A. T. & Keller, H. U. Stability of water ice under a porous nonvolatile layer: implications for the south polar layered deposits of Mars. Planet. Space Sci. 49(1), 59–63 (2001)

    ADS  CAS  Article  Google Scholar 

  24. 24

    Laskar, J. & Robutel, L. The chaotic obliquity of the planets. Nature 361, 608–612 (1993)

    ADS  Article  Google Scholar 

  25. 25

    Laskar, J., Gastineau, M., Joutel, F., Levrard, B. & Robutel, P. A new astronomical solution for the long term evolution of the insolation quantities of Mars. Lunar Planet. Sci. XXXV abstr. 1600 (2004).

  26. 26

    Haberle, R. M., Murphy, J. R. & Schaeffer, J. Orbital change experiments with a Mars general circulation model. Icarus 161, 66–89 (2003)

    ADS  Article  Google Scholar 

  27. 27

    Humphris, S. E., Zierenberg, R. A., Mullineaux, L. S. & Thomson, R. E. (eds) Seafloor Hydrothermal Systems 1–466 (AGU Geophys. Monogr. 91, American Geophysical Union, Washington, DC, 1995)

  28. 28

    Greenberg, R., Geissler, P., Tufts, B. R. & Hoppa, G. V. Habitability of Europa's crust: The role of tidal-tectonic processes. J. Geophys. Res. 105, 17551–17562 (2000)

    ADS  Article  Google Scholar 

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We thank M. Wählisch for assistance in the MOLA processing and S. Clifford and N. A. Cabrol for criticism that greatly improved the paper.

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Correspondence to John B. Murray.

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The authors declare that they have no competing financial interests.

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A list of all members of The HRSC Co-Investigator Team and their affiliations appears at the end of the paper

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Murray, J., Muller, J., Neukum, G. et al. Evidence from the Mars Express High Resolution Stereo Camera for a frozen sea close to Mars' equator. Nature 434, 352–356 (2005). https://doi.org/10.1038/nature03379

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