Discovery of a flank caldera and very young glacial activity at Hecates Tholus, Mars


The majority of volcanic products on Mars are thought to be mafic and effusive1,2. Explosive eruptions of basic to ultrabasic chemistry are expected to be common3,4, but evidence for them is rare and mostly confined to very old surface features5. Here we present new image and topographic data from the High Resolution Stereo Camera that reveal previously unknown traces of an explosive eruption at 30° N and 149° E on the northwestern flank of the shield volcano Hecates Tholus. The eruption created a large, 10-km-diameter caldera 350 million years ago. We interpret these observations to mean that large-scale explosive volcanism on Mars was not confined to the planet's early evolution. We also show that glacial deposits partly fill the caldera and an adjacent depression. Their age, derived from crater counts, is about 5 to 24 million years. Climate models predict that near-surface ice is not stable at mid-latitudes today6, assuming a thermo-dynamic steady state. Therefore, the discovery of very young glacial features at Hecates Tholus suggests recent climate changes. We show that the absolute ages of these very recent glacial deposits correspond very well to a period of increased obliquity of the planet's rotational axis7.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Topographic image map of the study area at the base of the northwestern flank of Hecates Tholus (part of HRSC image h0032_0000.nd).
Figure 2: Morphology of calderas.
Figure 3: Surface landforms indicative of fluvial and glacial processes at the northwestern flank of Hecates Tholus.
Figure 4: Chronology of glacial surface features and correlation to obliquity changes.


  1. 1

    Greeley, R. & Spudis, P. D. Volcanism on Mars. Rev. Geophys. Space Phys. 19, 13–41 (1981)

    ADS  CAS  Article  Google Scholar 

  2. 2

    Mouginis-Mark, P. J., Wilson, L. & Zuber, M. T. in Mars (eds Kieffer, H. H., Jakosky, B. M., Snyder, C. W. & Matthews, M. S.) 424–452 (Univ. Arizona Press, Tucson/London, 1992)

    Google Scholar 

  3. 3

    Francis, P. W. & Wood, C. A. Absence of silicic volcanism on Mars: Implications for crustal composition and volatile abundance. J. Geophys. Res. 87, 9881–9889 (1982)

    ADS  Article  Google Scholar 

  4. 4

    Wilson, L. & Head, J. W. Mars: review and analysis of volcanic eruption theory and relationships to observed landforms. Rev. Geophys. 32, 221–263 (1994)

    ADS  Article  Google Scholar 

  5. 5

    Greeley, R. & Crown, D. A. Volcanic geology of Tyrrhena Patera, Mars. J. Geophys. Res. 95, 7133–7149 (1993)

    ADS  Article  Google Scholar 

  6. 6

    Mellon, M. T. & Jakosky, B. M. The distribution and behaviour of martian ground ice during past and present epochs. J. Geophys. Res. 100, 11781–11799 (1995)

    ADS  Article  Google Scholar 

  7. 7

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

    ADS  Article  Google Scholar 

  8. 8

    Neukum, G. et al. HRSC: The High Resolution Stereo Camera of Mars Express 17–35 (Report ESA-SP-1240, European Space Agency Publications Division, Noordwijk, The Netherlands, 2004)

    Google Scholar 

  9. 9

    Mouginis-Mark, P. J., Wilson, L. & Head, J. W. Explosive Volcanism on Hecates Tholus, Mars: Investigation of Eruption Conditions. J. Geophys. Res. 87, 9890–9904 (1982)

    ADS  Article  Google Scholar 

  10. 10

    Wewel, F., Scholten, F. & Gwinner, K. High Resolution Stereo Camera (HRSC)—Multispectral 3D-data aquisition and photogrammetric data processing. Can. J. Remote Sens. 26, 466–474 (2000)

    ADS  Article  Google Scholar 

  11. 11

    Werner, S. C., Ivanov, B. A. & Neukum, G. Impact cratering on Mars: Search for target influence on morphology. Lunar Planet. Sci. XXXV, abstr. 1953 [CD-ROM] (Lunar and Planetary Institute, Houston, 2004)

    Google Scholar 

  12. 12

    Gulick, V. C. & Baker, V. R. Origin and evolution of valleys on martian volcanoes. J. Geophys. Res. 95, 14325–14344 (1990)

    ADS  Article  Google Scholar 

  13. 13

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

    ADS  Article  Google Scholar 

  14. 14

    Neukum, G. et al. Mars: 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 

  15. 15

    Squyres, S. W. Martian fretted terrain: flow of erosional debris. Icarus 34, 600–613 (1978)

    ADS  Article  Google Scholar 

  16. 16

    Mangold, N. Geomorphic analysis of lobate debris aprons on Mars at Mars Orbiter Camera scale: Evidence for ice sublimation initiated by fractures. J. Geophys. Res. 108, 8021, doi:10.1029/2002JE001885 (2003)

    Article  Google Scholar 

  17. 17

    Baker, V. R. Water and the martian landscape. Nature 412, 228–236 (2001)

    ADS  CAS  Article  Google Scholar 

  18. 18

    Wall, S. W. Analysis of condensates formed at the Viking 2 Lander site: The first winter. Icarus 47, 173–183 (1981)

    ADS  CAS  Article  Google Scholar 

  19. 19

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

    ADS  Article  Google Scholar 

  20. 20

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

    ADS  CAS  Article  Google Scholar 

  21. 21

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

    ADS  CAS  Article  Google Scholar 

  22. 22

    Feldman, W. C. et al. Global distribution of near-surface hydrogen on Mars. J. Geophys. Res. 109, E09006, doi:10.1029/2003JE002160 (2004)

    ADS  Article  Google Scholar 

  23. 23

    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)

    ADS  CAS  Article  Google Scholar 

  24. 24

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

    ADS  CAS  Article  Google Scholar 

  25. 25

    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, 5062, doi:10.1029/2003JE002051 (2003)

    Article  Google Scholar 

  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

    Skorov, Y. V. et al. Stability of water ice under a porous nonvolatile layer: implications to the south polar layered deposits of Mars. Planet. Space Sci. 49, 59–63 (2001)

    ADS  CAS  Article  Google Scholar 

  28. 28

    Marchant, D. R. et al. Formation of patterned ground and sublimation till over Miocene glacier ice in Beacon Valley, southern Victoria Land, Antarctica. Geol. Soc. Am. Bull. 114, 718–730 (2002)

    ADS  Article  Google Scholar 

  29. 29

    Mellon, M. T., Jakosky, B. M. & Postawko, S. E. The persistence of equatorial ground ice on Mars. J. Geophys. Res. 102, 19357–19369 (1997)

    ADS  Article  Google Scholar 

  30. 30

    Helbert, J. & Benkhoff, J. A new model on the thermal behavior of the near surface layer on Mars and its implications for ground ice deposits in Gusev Crater. 6th Int. Conf. Mars abstr. 3019 [CD-ROM] (Lunar and Planetary Institute, Houston, 2003)

    Google Scholar 

Download references


We thank the entire HRSC experiment and instrument teams at the German Aerospace Center (DLR) and at the Freie Universität Berlin, as well as the Mars Express teams at ESTEC and ESOC. This study would not have been possible without their work. In particular, we appreciate the support of H. Hoffmann, T. Roatsch, K.-D. Matz, V. Mertens, J. Flohrer, R. Pischel, F. Scholten and K. Gwinner. HRSC was developed at DLR and industrial partners. G.N. is the Principal Investigator of this experiment. We are grateful to U. Wolf for her support in crater counting. M. Aittola, J. Korteniemi, P. Kostama and D. Williams supported the HRSC image planning. T. Lowell provided an image of his collection of glacier photographs. Comments by J. Helbert helped to improve the manuscript.

Author information




Corresponding author

Correspondence to Ernst Hauber.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Additional information

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

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Hauber, E., van Gasselt, S., Ivanov, B. et al. Discovery of a flank caldera and very young glacial activity at Hecates Tholus, Mars. Nature 434, 356–361 (2005).

Download citation

Further reading


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.