Trace gas transport in the martian subsurface

Stevens, A. H.; Patel, M. R.; Ringrose, T. J.; Lewis, S. R. and Leese, M. R. (2013). Trace gas transport in the martian subsurface. In: UK Planetary Forum Early Career Scientists Meeting, 18 Jan 2013, Natural History Museum, UK.


A number of sources have been proposed for the methane observed in the atmosphere of Mars [1]. Serpentinisation could be a deep geologic source of the gas, where mafic minerals interact with a subsurface water table. [2] If so, the methane produced would have to travel through kilometres of megaregolith before entering the atmosphere. Although the structure of the martian subsurface is poorly known, this transport can be modelled using carefully chosen parameters and a modified form of Fick’s laws [3]. Such a model can be used to estimate transport timescales and investigate the properties of release.

Methane clathrate hydrates are a potentially shallower methane source as they could be stable up to depths of only a few metres near the martian poles. The dissociation of these deposits could more easily explain the observed variation of methane in the atmosphere, as they would be more directly influenced by surface temperature changes [4]. To investigate the potential contributions of methane clathrate hydrates, we create samples in the lab and investigate their behaviour under Mars conditions in environmental simulation chambers.

Combining the results of these models and experiments with data from future missions such as the ExoMars Trace Gas Orbiter will allow constraints to be placed on the potential sources of trace gases observed in the martian atmosphere.

1. Atreya, S.K., et al., Planetary and Space Science, 2011. 59(2-3): p. 133-136.
2. Oze, C. and M. Sharma, Geophys. Res. Lett., 2005. 32(10): p. L10203.
3. Sizemore, H.G. and M.T. Mellon, Icarus, 2008. 197(2): p. 606-620.
4. Root, M.J. and M.E. Elwood Madden, Icarus, 2012. 218(1): p. 534-544.

Viewing alternatives

Download history

Item Actions