Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Valley formation on early Mars by subglacial and fluvial erosion


The southern highlands of Mars are dissected by hundreds of valley networks, which are evidence that water once sculpted the surface. Characterizing the mechanisms of valley incision may constrain early Mars climate and the search for ancient life. Previous interpretations of the geological record require precipitation and surface water runoff to form the valley networks, in contradiction with climate simulations that predict a cold, icy ancient Mars. Here we present a global comparative study of valley network morphometry, using a principal-component-based analysis with physical models of fluvial, groundwater sapping and glacial and subglacial erosion. We found that valley formation involved all these processes, but that subglacial and fluvial erosion are the predominant mechanisms. This is supported by predictions from models of steady-state erosion and geomorphological comparisons to terrestrial analogues. The inference of subglacial channels among the valley networks supports the presence of ice sheets that covered the southern highlands during the time of valley network emplacement.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Distribution of analysed valley networks. Global map of Mars showing a blended MOLA/HRSC DEM overlain with valley network streamlines (purple).
Fig. 2: PCA classification and confidence.
Fig. 3: Valley network origin in the context of the Icy Highlands model.
Fig. 4: Comparative morphology of Martian and terrestrial subglacial systems.

Data availability

Datasets generated during the current study, which include observations, model parameters and longitudinal profile data have been deposited in the Zenodo repository at and are included in this article as Supplementary tables.

Code availability

Data analysis codes include the PCA (available as the MATLAB built-in function pca) as well as custom codes specifically generated for data and error extraction, error propagation, confidence analysis and modelling of the synthetic fluvial, glacial, sapping and subglacial valley networks. The authors will provide the custom codes in a MATLAB live script format (.mlx) upon request.


  1. 1.

    Carr, M. H. The Martian drainage system and the origin of valley networks and fretted channels. J. Geophys. Res. Planet. 100, 7479–7507 (1995).

    Google Scholar 

  2. 2.

    Williams, R. M. & Phillips, R. J. Morphometric measurements of Martian valley networks from Mars Orbiter Laser Altimeter (MOLA) data. J. Geophys. Research Planet. 106, 23737–23751 (2001).

    Google Scholar 

  3. 3.

    Gulick, V. C. Origin of the valley networks on Mars: a hydrological perspective. Geomorphology 37, 241–268 (2001).

    Google Scholar 

  4. 4.

    Hynek, B. M., Beach, M. & Hoke, M. R. Updated global map of Martian valley networks and implications for climate and hydrologic processes. J. Geophys. Res. Planet. 115, E090008 (2010).

    Google Scholar 

  5. 5.

    Carr, M. H. & Clow, G. D. Martian channels and valleys: their characteristics, distribution, and age. Icarus 48, 91–117 (1981).

    Google Scholar 

  6. 6.

    Laity, J. E. & Malin, M. C. Sapping processes and the development of theater-headed valley networks on the Colorado Plateau. Geol. Soc. Am. Bull. 96, 203–217 (1985).

    Google Scholar 

  7. 7.

    Kargel, J. S. & Strom, R. G. Ancient glaciation on Mars. Geology 20, 3–7 (1992).

    Google Scholar 

  8. 8.

    Lee, P. A Unique Mars/early Mars analog on Earth: the Haughton impact structure Devon Island, Canadian Arctic. In Conference on Early Mars: Geologic and Hydrologic Evolution, Physical and Chemical Environments, and the Implications for Life (eds Clifford, S. M., Treiman, A. H., Newsom, H. E. & Farmer, J. D.) 50 (LPI Contribution no. 916, Lunar and Planetary Institute, 1997).

  9. 9.

    Craddock, R. A. & Howard, A. D. The case for rainfall on a warm, wet early Mars. J. Geophys. Res. Planet. 107, 5111 (2002).

    Google Scholar 

  10. 10.

    Howard, A. D., Moore, J. M. & Irwin, R. P. An intense terminal epoch of widespread fluvial activity on early Mars: 1. Valley network incision and associated deposits. J. Geophys. Res. Planet. 110, E12S14 (2005).

    Google Scholar 

  11. 11.

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

  12. 12.

    Lamb, M. P. et al. Can springs cut canyons into rock? J. Geophys. Res. Planet. 111, E07002 (2006).

    Google Scholar 

  13. 13.

    Sharp, R. P. & Malin, M. C. Channels on Mars. Geol. Soc. Am. Bull. 86, 593–609 (1975).

    Google Scholar 

  14. 14.

    Wordsworth, R. et al. Global modelling of the early Martian climate under a denser CO2 atmosphere: water cycle and ice evolution. Icarus 222, 1–19 (2013).

    Google Scholar 

  15. 15.

    Fastook, J. L. & Head, J. W. Glaciation in the Late Noachian Icy Highlands: ice accumulation, distribution, flow rates, basal melting, and top-down melting rates and patterns. Planet. Space Sci. 106, 82–98 (2015).

    Google Scholar 

  16. 16.

    Grau Galofre, A. & Jellinek, M. A. The geometry and complexity of spatial patterns of terrestrial channel networks: distinctive fingerprints of erosional regimes. J. Geophys. Res. Earth Surf. 122, 1037–1059 (2017).

    Google Scholar 

  17. 17.

    Grau Galofre, A., Jellinek, A. M., Osinski, G., Zanetti, M. & Kukko, A. Subglacial drainage patterns of Devon Island, Canada: detailed comparison of river and subglacial channels. Cryosphere 12, 1461–1478 (2018).

    Google Scholar 

  18. 18.

    Shreve, R. Movement of water in glaciers. J. Glaciol. 11, 205–214 (1972).

    Google Scholar 

  19. 19.

    Sugden, D. E., Denton, G. H. & Marchant, D. R. Subglacial meltwater channel systems and ice sheet overriding, Asgard Range, Antarctica. Geogr. Annal. A 73, 109–121 (1991).

    Google Scholar 

  20. 20.

    Greenwood, S. L., Clark, C. D. & Hughes, A. L. Formalising an inversion methodology for reconstructing ice-sheet retreat patterns from meltwater channels: application to the British Ice Sheet. J. Quatern. Sci. 22, 637–645 (2007).

    Google Scholar 

  21. 21.

    Kehew, A. E., Piotrowski, J. A. & Jørgensen, F. Tunnel valleys: concepts and controversies—a review. Earth Sci. Rev. 113, 33–58 (2012).

    Google Scholar 

  22. 22.

    Hobley, D. E., Howard, A. D. & Moore, J. M. Fresh shallow valleys in the Martian midlatitudes as features formed by meltwater flow beneath ice. J. Geophys. Res. Planet. 119, 128–153 (2014).

    Google Scholar 

  23. 23.

    Kleman, J. & Hättestrand, C. Frozen-bed Fennoscandian and Laurentide ice sheets during the Last Glacial Maximum. Nature 402, 63–66 (1999).

    Google Scholar 

  24. 24.

    Dyke, A. Last Glacial Maximum and deglaciation of Devon Island, Arctic Canada: support for an Innuitian Ice Sheet. Quatern. Sci. Rev. 18, 393–420 (1999).

    Google Scholar 

  25. 25.

    Hättestrand, C. & Stroeven, A. P. A relict landscape in the centre of Fennoscandian glaciation: geomorphological evidence of minimal Quaternary glacial erosion. Geomorphology 44, 127–143 (2002).

    Google Scholar 

  26. 26.

    England, J. et al. The Innuitian Ice Sheet: configuration, dynamics and chronology. Quatern. Sci. Rev. 25, 689–703 (2006).

    Google Scholar 

  27. 27.

    Walder, J. & Hallet, B. Geometry of former subglacial water channels and cavities. J. Glaciol. 23, 335–346 (1979).

    Google Scholar 

  28. 28.

    Malin, M. C. & Carr, M. H. Groundwater formation of Martian valleys. Nature 397, 589–591 (1999).

    Google Scholar 

  29. 29.

    Whipple, K. X. & Tucker, G. E. Dynamics of the stream-power river incision model: implications for height limits of mountain ranges, landscape response timescales, and research needs. J. Geophys. Res. Solid Earth 104, 17661–17674 (1999).

    Google Scholar 

  30. 30.

    Parker, G., Wilcock, P. R., Paola, C., Dietrich, W. E. & Pitlick, J. Physical basis for quasi-universal relations describing bankfull hydraulic geometry of single-thread gravel bed rivers. J. Geophys. Res. Earth Surface 112, F04005 (2007).

    Google Scholar 

  31. 31.

    Perron, J. T., Dietrich, W. E. & Kirchner, J. W. Controls on the spacing of first-order valleys. J. Geophys. Res. Earth Surface 113, F04016 (2008).

    Google Scholar 

  32. 32.

    Wordsworth, R. D., Kerber, L., Pierrehumbert, R. T., Forget, F. & Head, J. W. Comparison of ‘warm and wet’ and ‘cold and icy’ scenarios for early Mars in a 3-D climate model. J. Geophys. Res. Planet. 120, 1201–1219 (2015).

    Google Scholar 

  33. 33.

    Schoof, C. Ice-sheet acceleration driven by melt supply variability. Nature 468, 803–806 (2010).

    Google Scholar 

  34. 34.

    Rennermalm, A. K. et al. Understanding Greenland ice sheet hydrology using an integrated multi-scale approach. Environ. Res. Lett. 8, 015017 (2013).

    Google Scholar 

  35. 35.

    Christensen, P. R. Water at the poles and in permafrost regions of Mars. Elements 2, 151–155 (2006).

    Google Scholar 

  36. 36.

    Carr, M. & Head, J. Martian surface/near-surface water inventory: sources, sinks, and changes with time. Geophys. Res. Lett. 42, 726–732 (2015).

    Google Scholar 

  37. 37.

    Cuffey, K. M. & Paterson, W. S. B. The Physics of Glaciers (Academic, 2010).

  38. 38.

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

    Google Scholar 

  39. 39.

    Wordsworth, R. D. The climate of early Mars. Ann. Rev. Earth Planet. Sci. 44, 381–408 (2016).

    Google Scholar 

  40. 40.

    Palumbo, A. M. & Head, J. W. Early Mars climate history: characterizing a ‘warm and wet’ Martian climate with a 3D global climate model and testing geological predictions. Geophys. Res. Lett. 45, 10249–10258 (2018).

    Google Scholar 

  41. 41.

    Rosenberg, E. N., Palumbo, A. M., Cassanelli, J. P., Head, J. W. & Weiss, D. K. The volume of water required to carve the Martian valley networks: improved constraints using updated methods. Icarus 317, 379–387 (2019).

    Google Scholar 

  42. 42.

    Head, J. W. & Pratt, S. Extensive Hesperian-aged south polar ice sheet on Mars: evidence for massive melting and retreat, and lateral flow and ponding of meltwater. J. Geophys. Res. Planet. 106, 12275–12299 (2001).

    Google Scholar 

  43. 43.

    Fastook, J. L., Head, J. W., Marchant, D. R., Forget, F. & Madeleine, J.-B. Early Mars climate near the Noachian–Hesperian boundary: Independent evidence for cold conditions from basal melting of the south polar ice sheet (Dorsa Argentea Formation) and implications for valley network formation. Icarus 219, 25–40 (2012).

    Google Scholar 

  44. 44.

    Butcher, F. E., Conway, S. J. & Arnold, N. S. Are the Dorsa Argentea on Mars eskers? Icarus 275, 65–84 (2016).

    Google Scholar 

  45. 45.

    Orosei, R. et al. Radar evidence of subglacial liquid water on Mars. Science 361, 490–493 (2018).

    Google Scholar 

  46. 46.

    Irwin, R. P., Howard, A. D., Craddock, R. A. & Moore, J. M. An intense terminal epoch of widespread fluvial activity on early Mars: 2. Increased runoff and paleolake development. J. Geophys. Res. Planet. 110, E12S15 (2005).

    Google Scholar 

  47. 47.

    Ansan, V., Mangold, N., Masson, P., Gailhardis, E. & Neukum, G. Topography of valley networks on Mars from Mars Express High Resolution Stereo Camera digital elevation models. J. Geophys. Res. Planet. 113, E07006 (2008).

    Google Scholar 

  48. 48.

    Carr, M. H. & Malin, M. C. Meter-scale characteristics of Martian channels and valleys. Icarus 146, 366–386 (2000).

    Google Scholar 

  49. 49.

    Rains, R. B. et al. Subglacial tunnel channels, Porcupine Hills, Southwest Alberta, Canada. Quatern. Int. 90, 57–65 (2002).

    Google Scholar 

  50. 50.

    Sissons, J. A subglacial drainage system by the Tinto Hills, Lanarkshire. Trans. Edin. Geol. Soc. 18, 175–193 (1961).

    Google Scholar 

  51. 51.

    Pieri, D. C. Martian valleys—morphology, distribution, age, and origin. Science 210, 895–897 (1980).

    Google Scholar 

  52. 52.

    Smith, D. E. et al. Mars Orbiter Laser Altimeter: experiment summary after the first year of global mapping of Mars. J. Geophys. Res. Planet. 106, 23689–23722 (2001).

    Google Scholar 

  53. 53.

    Horton, R. E. Erosional development of streams and their drainage basins; hydrophysical approach to quantitative morphology. Geol. Soc. Am. Bull. 56, 275–370 (1945).

    Google Scholar 

  54. 54.

    Stepinski, T. & Stepinski, A. Morphology of drainage basins as an indicator of climate on early Mars. J. Geophys. Res. Planet. 110, E12S12 (2005).

    Google Scholar 

  55. 55.

    Bue, B. D. & Stepinski, T. F. Automated classification of landforms on Mars. Computat. Geosci. 32, 604–614 (2006).

    Google Scholar 

Download references


A.G.G., A.M.J. and G.R.O. were supported through the NSERC Discovery grant program. A.G.G. also received support through an NSERC CREATE-funded fellowship and through an Exploration Fellowship from the School of Earth and Space Exploration, ASU. Arctic fieldwork was supported through PCSP and NSERC Northern Research Supplement Grants to G.R.O. Our appreciation goes to C. Schoof, R. Phillips, K. Whipple and P. Christensen for their insightful comments, and to the MJ-CJ research group for continued support.

Author information




A.G.G. and A.M.J conceived the study. A.G.G. carried out all the calculations, performed the data analysis summarized in Figs. 2–4 and took the lead in writing the paper with A.M.J. G.O. provided critical comments related particularly to geological controls on the history of Mars surface processes. All the authors contributed to constructing the discussion and implications for Mars’ hydrosphere and early climate.

Corresponding author

Correspondence to Anna Grau Galofre.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Primary handling editor: Stefan Lachowycz.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 PCA endmember examples.

Examples of the four groups of valley networks as derived from the PCA classification: Warrego valles, fluvial (a), unnamed valley (M68), glacial (b), Abus vallis, sapping (c), and Pallacopas valles, subglacial (d). Images show colorized elevation (MOLA, Goddard Space Flight Center) overlying a THEMIS (ASU/NASA) mosaic.

Supplementary information

Supplementary Information

Supplementary methods including Figs. 1–13 and Table 1.

Supplementary Data 1

Main dataset. The table is structured so that each row is a valley network and columns include the ID number, valley name (if applicable), latitude/longitude, and the six metrics and their respective error.

Supplementary Data 2

This table includes two sheets. The first is the table of parameters, where each row is a parameter, and columns are the parameter symbol, definition, units, values (lower, average, and upper bounds), and references. The second sheet contains the metric predictions (upper, average, and lower values).

Supplementary Data 3

PCA classification and confidence results of the study. Rows correspond to valley networks, whereas columns give their ID, name, latitude/longitude, the distances to each of the synthetic valley network erosional groups, the relative distances, distances minus statistical threshold, and the final classification result (1 is fluvial, 2 is glacial, 3 is sapping, 4 is subglacial, 5 is undifferentiated). The last column, confidence, goes from highest (1) to lowest (4).

Supplementary Data 4

Longitudinal profile observations and undulation interpretations. Rows correspond to valley networks, columns are valley network ID, name, and a description of the longitudinal profile undulations and interpretations.

Supplementary Data 5

Sensitivity analysis for the principal component results. The first sheet contains the sensitivity analysis summary, columns are the sample size and the five metrics. The second sheet contains a total of 35 individual analysis for different sample sizes, as indicated.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Grau Galofre, A., Jellinek, A.M. & Osinski, G.R. Valley formation on early Mars by subglacial and fluvial erosion. Nat. Geosci. 13, 663–668 (2020).

Download citation

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing