On the secular evolution of groundwater on Mars
Article first published online: 18 DEC 2009
Copyright 2009 by the American Geophysical Union.
Geophysical Research Letters
Volume 36, Issue 24, December 2009
How to Cite
2009), On the secular evolution of groundwater on Mars, Geophys. Res. Lett., 36, L24803, doi:10.1029/2009GL041018., and (
- Issue published online: 18 DEC 2009
- Article first published online: 18 DEC 2009
- Manuscript Accepted: 24 NOV 2009
- Manuscript Revised: 20 NOV 2009
- Manuscript Received: 16 SEP 2009
- obliquity variations;
- heat flow;
 We modeled the subsurface transport of H2O and CO2 on Mars in a two-dimensional pole-to-equator cross-section, starting with sudden surface freezing representing ancient climate change. We find that excursions to low obliquity strongly drive ice sublimation and subsequent groundwater evaporation at low latitudes. This creates a hydraulic gradient in the saturated zone that moves water equatorward and even sublimates the base of high-latitude ice. Eventually, all H2O is lost at latitudes less than ∼30°. A subcryospheric vadose zone may be retained at higher latitudes, but ultimately only a few monolayers of adsorbed water will be held. A subcryospheric phreatic zone is preserved in the same regions only where lateral heterogeneity restricts horizontal fluid flow. The predicted contemporary state of Mars is drier and with groundwater—if present at all—in different locations than previously considered.