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Recent ice-rich deposits formed at high latitudes on Mars by sublimation of unstable equatorial ice during low obliquity


Observations from the gamma-ray spectrometer instrument suite on the Mars Odyssey spacecraft have been interpreted as indicating the presence of vast reservoirs of near-surface ice in high latitudes of both martian hemispheres1,2,3,4,5. Ice concentrations are estimated to range from 70 per cent at 60° latitude to 100 per cent near the poles, possibly overlain by a few centimetres of ice-free material in most places4. This result is supported by morphological evidence of metres-thick layered deposits that are rich in water-ice6,7,8,9 and periglacial-like features10,11 found only at high latitudes. Diffusive exchange of water between the pore space of the regolith and the atmosphere has been proposed to explain this distribution12, but such a degree of concentration is difficult to accommodate with such processes9,13,14. Alternatively, there are suggestions that ice-rich deposits form by transport of ice from polar reservoirs and direct redeposition in high latitudes during periods of higher obliquity9,13, but these results have been difficult to reproduce with other models. Here we propose instead that, during periods of low obliquity (less than 25°), high-latitude ice deposits form in both hemispheres by direct deposition of ice, as a result of sublimation from an equatorial ice reservoir that formed earlier, during a prolonged high-obliquity excursion. Using the ice accumulation rates estimated from global climate model simulations we show that, over the past ten million years, large variations of Mars' obliquity have allowed the formation of such metres-thick, sedimentary layered deposits in high latitude and polar regions.

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Figure 1: Evolution of the martian obliquity in the past 10 Myr.
Figure 2: Surface water ice budget (in millimetres per martian year) for a 40° obliquity during simulation year 11, with superimposed MOLA topography.
Figure 3: Surface water ice budget in mm per martian year after ten years of simulation for various obliquities, and with an example of equatorial ice reservoir situated around Arsia and Pavonis Montes.


  1. Mitrofanov, I. et al. Maps of subsurface hydrogen from the high energy neutron detector, Mars Odyssey. Science 297, 78–81 (2002)

    Article  ADS  CAS  Google Scholar 

  2. Boynton, W. V. et al. Distribution of hydrogen in the near surface of Mars: evidence for subsurface ice deposits. Science 297, 81–85 (2002)

    Article  ADS  CAS  Google Scholar 

  3. Feldman, W. C. et al. Global distribution of neutrons from Mars. Science 297, 75–78 (2002)

    Article  ADS  CAS  Google Scholar 

  4. Boynton, W. V. et al. Constraints on the distribution of hydrogen in the polar regions of Mars and implications for ice formation processes. AGU Fall Meeting Abstr. Abst. P32B-05 (2003)

  5. Feldman, W. C. et al. The global distribution of near-surface hydrogen on Mars. J. Geophys. Res. 109(E6), doi:10.1029/2003JE002160 (2004)

  6. Mustard, J. F., Cooper, C. D. & Rifkin, M. K. Evidence for recent climate change on Mars from the identification of youthful near-surface ground ice. Nature 412, 411–414 (2001)

    Article  ADS  CAS  Google Scholar 

  7. Kreslavsky, M. A. & Head, J. W. Kilometre-scale roughness of Mars: Results from MOLA data analysis. J. Geophys. Res. 105, 26695–26711 (2000)

    Article  ADS  Google Scholar 

  8. Kreslavsky, M. A. & Head, J. W. Nature and evolution of young latitude-dependent water-ice rich mantle. Geophys. Res. Lett. 29, doi:10.1029/2002GL015392 (2002)

  9. Head, J. W., Mustard, J. F., Kreslavsky, M. A., Milliken, R. E. & Marchant, D. R. Recent ice ages on Mars. Nature 426, 797–802 (2003)

    Article  ADS  CAS  Google Scholar 

  10. Mangold, N., Maurice, S., Feldman, W. C., Costard, F. & Forget, F. Geographical relationships between small scale polygons and ground ice distribution from neutron spectrometer on Mars. Third Mars Polar Sci. Conf. Abst. 8043 (2003)

  11. Milliken, R. E. et al. Viscous flow features on the surface of Mars. J. Geophys. Res. 108(E6), doi:10.1029/2002JE002005 (2003)

  12. Mellon, M. T., Feldman, W. C. & Prettyman, T. H. The presence and stability of ground ice in the Southern hemisphere of Mars. Icarus 169, 324–340 (2004)

    Article  ADS  CAS  Google Scholar 

  13. Mischna, M. A., Richardson, M. I., Wilson, R. J. & McCleese, D. J. On the orbital forcing of Martian water and CO2 cycles: A general circulation model study with simplified volatile schemes. J. Geophys. Res. 108(E6), doi:10.1029/2003JE002051 (2003)

  14. Mischna, M. A., McCleese, D. J., Richardson, M. I., Vasavada, A. R. & Wilson, R. J. Volatile cycling and layering on Mars: Observations, theory and modeling. 6th Int. Mars Conf. Abst. 3145 (2003)

  15. Hays, J. D., Imbrie, J. & Shackleton, N. J. Variations of the Earth's Orbit: pacemaker of the ice ages. Science 194, 1121–1132 (1976)

    Article  ADS  CAS  Google Scholar 

  16. Jakosky, B. M. & Carr, M. H. Possible precipitation of ice at low latitudes of Mars during periods of high obliquity. Nature 315, 559–561 (1985)

    Article  ADS  CAS  Google Scholar 

  17. Jakosky, B. M., Henderson, B. G. & Mellon, M. T. Chaotic obliquity and the nature of the Martian climate. J. Geophys. Res. 100, 1579–1584 (1995)

    Article  ADS  CAS  Google Scholar 

  18. Haberle, R. M. et al. The Martian water cycle at high obliquity. Lunar Planet. Sci. Conf. XXXI Abst. 1509 (2000)

  19. Richardson, M. I. & Wilson, R. J. Investigation of the nature and stability of the Martian seasonal water cycle with a general circulation model. J. Geophys. Res. 107(E5), doi:10.1029/2001JE001536 (2002)

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

    Article  ADS  Google Scholar 

  21. Touma, J. & Wisdom, J. The chaotic obliquity of Mars. Science 259, 1294–1297 (1993)

    Article  ADS  CAS  Google Scholar 

  22. Laskar, J., Levrard, B. & Mustard, J. F. Orbital forcing of the martian polar layered deposits. Nature 419, 375–377 (2002)

    Article  ADS  CAS  Google Scholar 

  23. Laskar, J. et al. Long term evolution and chaotic diffusion of the insolation quantities of Mars. Icarus 170, 343–364 (2004)

    Article  ADS  Google Scholar 

  24. Hourdin, F., Forget, F. & Talagrand, O. Meteorological variability and the annual surface pressure cycle on Mars. J. Atmos. Sci. 50, 3625–3640 (1993)

    Article  ADS  Google Scholar 

  25. Forget, F. et al. Improved General Circulation Models of the Martian atmosphere from the surface to above 80 km. J. Geophys. Res. 104, 24155–24176 (1999)

    Article  ADS  CAS  Google Scholar 

  26. Montmessin, F., Forget, F., Rannou, P., Cabane, M. & Haberle, R. M. Origin and role of water ice clouds in the Martian water cycle as inferred from a general circulation model. J. Geophys. Res. 109(E10), doi:10.1029/2004JE002284 (2004)

  27. Smith, M. D. The annual cycle of water vapor on Mars as observed by the Thermal Emission Spectrometer. J. Geophys. Res. 107(E6), 10.1029/2001JE001522 (2002)

  28. Head, J. W. & Marchant, D. R. Cold-based moutain glaciers on Mars: Western Arsia Mons. Geology 31, 641–644 (2003)

    Article  ADS  Google Scholar 

  29. Shean, D. E., Head, J. W., Fastook, J. L. & Marchant, D. R. Tharsis Montes cold-based glaciers: Observations and constraints for modeling and preliminary results. Lunar Planet. Sci. Conf. XXXV Abst. 1428 (2004)

  30. Richardson, M. I. & Wilson, R. J. A topographically forced asymmetry in the martian circulation and climate. Nature 416, 298–301 (2002)

    Article  ADS  CAS  Google Scholar 

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We acknowledge R. M. Haberle and G. L. Tyler for useful discussions and comments. This work was supported by the CNRS-PNP programme.

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Correspondence to Benjamin Levrard.

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Levrard, B., Forget, F., Montmessin, F. et al. Recent ice-rich deposits formed at high latitudes on Mars by sublimation of unstable equatorial ice during low obliquity. Nature 431, 1072–1075 (2004).

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