Active dark flows known as recurring slope lineae have been observed on the warmest slopes of equatorial Mars. The morphology, composition and seasonality of the lineae suggest a role of liquid water in their formation. However, internal and atmospheric sources of water appear to be insufficient to sustain the observed slope activity. Experimental evidence suggests that under the low atmospheric pressure at the surface of Mars, gas can flow upwards through porous Martian soil due to thermal creep under surface regions heated by the Sun, and disturb small particles. Here we present numerical simulations to demonstrate that such a dry process involving the pumping of rarefied gas in the Martian soil due to temperature contrasts can explain the formation of the recurring slope lineae. In our simulations, solar irradiation followed by shadow significantly reduces the angle of repose due to the resulting temporary temperature gradients over shaded terrain, and leads to flow at intermediate slope angles. The simulated flow locations are consistent with observed recurring slope lineae that initiate in rough and bouldered terrains with local shadows over the soil. We suggest that this dry avalanche process can explain the formation of the recurring slope lineae on Mars without requiring liquid water or CO2 frost activity.
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McEwen, A. S. et al. Seasonal flows on warm Martian slopes. Science 333, 740–743 (2011).
McEwen, A. S. et al. Recurring slope lineae in equatorial regions of Mars. Nat. Geosci. 7, 53–58 (2014).
Chojnacki, M. et al. Geologic context of recurring slope lineae in melas and coprates chasmata, Mars. J. Geophys. Res. 121, 1204–1231 (2016).
Ojha, L. et al. Spectral evidence for hydrated salts in recurring slope lineae on Mars. Nat. Geosci. 8, 829–832 (2015).
Massé, M. et al. Transport processes induced by metastable boiling water under Martian surface conditions. Nat. Geosci. 9, 425–428 (2016).
Smith, M. D. The annual cycle of water vapor on Mars as observed by the Thermal Emission Spectrometer. J. Geophys. Res. 107, 5115 (2002).
Vincendon, M., Forget, F. & Mustard, J. Water ice at low to midlatitudes on Mars. J. Geophys. Res. 115, E10001 (2010).
Schorghofer, N. Dynamics of ice ages on Mars. Nature 449, 192–194 (2007).
Vincendon, M. et al. Near-tropical subsurface ice on Mars. Geophys. Res. Lett. 37, L01202 (2010).
Edwards, C. S. & Piqueux, S. The water content of recurring slope lineae on Mars. Geophys. Res. Lett. 43, 8912–8919 (2016).
Piqueux, S. et al. Discovery of a widespread low-latitude diurnal CO2 frost cycle on Mars. J. Geophys. Res. 121, 1174–1189 (2016).
Shinbrot, T., Duong, N.-H., Kwan, L. & Alvarez, M. M. Dry granular flows can generate surface features resembling those seen in Martian gullies. Proc. Natl Acad. Sci. USA 101, 8542–8546 (2004).
Mangold, N., Mangeney, A. & Bouchut, F. Workshop on Martian Gullies Vol. 1303, 70–71 (LPI Contributions, 2008).
Félix, G. & Thomas, N. Relation between dry granular flow regimes and morphology of deposits: formation of levées in pyroclastic deposits. Earth Planet. Sci. Lett. 221, 197–213 (2004).
Costard, F., Mangold, N., Baratoux, D. & Forget, F. Seventh International Conference on Mars Vol. 1353, 3133 (LPI Contributions, 2007).
Legros, F. Can dispersive pressure cause inverse grading in grain flows? J. Sedim. Res. 72, 166–170 (2002).
Armanini, A. Granular flows driven by gravity. J. Hydraul. Res. 51, 111–120 (2013).
Kokelaar, B., Graham, R., Gray, J. & Vallance, J. Fine-grained linings of leveed channels facilitate runout of granular flows. Earth Planet. Sci. Lett. 385, 172–180 (2014).
Wurm, G. & Krauss, O. Dust eruptions by photophoresis and solid state greenhouse effects. Phys. Rev. Lett. 96, 134301 (2006).
Kelling, T., Wurm, G., Kocifaj, M., Klačka, J. & Reiss, D. Dust ejection from planetary bodies by temperature gradients: laboratory experiments. Icarus 212, 935–940 (2011).
Wurm, G., Teiser, J. & Reiss, D. Greenhouse and thermophoretic effects in dust layers: the missing link for lifting of dust on Mars. Geophys. Res. Lett. 35, 10201 (2008).
de Beule, C. et al. The Martian soil as a planetary gas pump. Nat. Phys. 10, 17–20 (2013).
Küpper, M. et al. Photophoresis on polydisperse basalt microparticles under microgravity. J. Aerosol Sci. 76, 126–137 (2014).
Kocifaj, M., Klačka, J., Wurm, G., Kelling, T. & Kohút, I. Dust ejection from (pre-)planetary bodies by temperature gradients: radiative and heat transfer. Mon. Not. R. Astron. Soc. 404, 1512–1518 (2014).
Kocifaj, M., Klačka, J., Kelling, T. & Wurm, G. Radiative cooling within illuminated layers of dust on (pre)-planetary surfaces and its effect on dust ejection. Icarus 211, 832–838 (2011).
de Beule, C., Wurm, G., Kelling, T., Koester, M. & Kocifaj, M. An insolation activated dust layer on Mars. Icarus 260, 23–28 (2015).
Küpper, M. & Wurm, G. Thermal creep-assisted dust lifting on Mars: wind tunnel experiments for the entrainment threshold velocity. J. Geophys. Res. 120, 1346–1356 (2015).
Kuepper, M. & Wurm, G. Amplification of dust loading in Martian dust devils by self-shadowing. Icarus 274, 249–252 (2016).
Schorghofer, N. Planetary science: subsurface air flow on Mars. Nat. Phys. 10, 14–15 (2014).
Lewis, S. R. et al. A climate database for Mars. J. Geophys. Res. 104, 24177–24194 (1999).
Spiga, A. & Forget, F. Fast and accurate estimation of solar irradiance on Martian slopes. Geophys. Res. Lett. 35, 15201 (2008).
Pouliquen, O. Scaling laws in granular flows down rough inclined planes. Phys. Fluids 11, 542 (1999).
Schmidt, F. et al. Albedo control of seasonal South Polar Cap recession on Mars. Icarus 200, 374–394 (2009).
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).
Millour, E. et al. (MCD/GCM development team) The Mars Climate Database (MCD version 5.2) EPSC2015-438 (European Planetary Science Congress, 2015).
Smith, M. D., Pearl, J. C., Conrath, B. J. & Christensen, P. R. Thermal Emission Spectrometer results: Mars atmospheric thermal structure and aerosol distribution. J. Geophys. Res. 106, 23929–23945 (2001).
Ockert-Bell, M. E., Bell, J. F., Pollack, J. B., McKay, C. P. & Forget, F. Absorption and scattering properties of the Martian dust in the solar wavelengths. J. Geophys. Res. 102, 9039–9050 (1997).
Pollack, J. B., Toon, O. B. & Khare, B. N. Optical properties of some terrestrial rocks and glasses. Icarus 19, 372–389 (1973).
Wolff, M. J. et al. Wavelength dependence of dust aerosol single scattering albedo as observed by the Compact Reconnaissance Imaging Spectrometer. J. Geophys. Res. 114, E00D04 (2009).
Han, Y.-L. Investigation of Micro/Meso-Scale Knudsen Compressors at Low Pressures PhD thesis, Univ. Southern California (2006).
Sone, Y. & Itakura, E. Analysis of Poiseuille and thermal transpiration flows for arbitrary Knudsen numbers by a modified Knudsen number expansion method and their database. J. Vac. Soc. Japan 33, 92–94 (1990).
Mangeney, A., Bouchut, F., Thomas, N., Vilotte, J. P. & Bristeau, M. O. Numerical modeling of self-channeling granular flows and of their levee-channel deposits. J. Geophys. Res. 112, F02017 (2007).
Pouliquen, O. & Forterre, Y. Friction law for dense granular flows: application to the motion of a mass down a rough inclined plane. J. Fluid Mech. 453, 133–151 (2002).
We acknowledge support from the ‘Institut National des Sciences de l’Univers’ (INSU), the ‘Centre National de la Recherche Scientifique’ (CNRS) and ‘Centre National d’Etude Spatiale’ (CNES) through the ‘Programme National de Planétologie’, HRSC/MEX, OMEGA/MEX and PFS/MEX programmes. Computational work was supported by the Slovak Research and Development Agency under contract No. APVV-14-0017. This work is supported by the Center for Data Science, funded by the IDEX Paris-Saclay, ANR-11-IDEX-0003-02. We thank S. Piqueux for fruitful remarks.
The authors declare no competing financial interests.
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Schmidt, F., Andrieu, F., Costard, F. et al. Formation of recurring slope lineae on Mars by rarefied gas-triggered granular flows. Nature Geosci 10, 270–273 (2017). https://doi.org/10.1038/ngeo2917
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