HR: 0830h
AN: P11B-1038    [PDF]
TI: A Numerical Study of Possible Water Distribution in the Subsurface of Mars
AU: * Travis, B
EM: bjtravis@lanl.gov
AF: Los Alamos National Laboratory, EES-2/MS-T003, Los Alamos, NM 87545 United States
AB: Many studies of surface features on Mars conclude that large quantities of water were released across the Martian surface early in Mars' history, and that water may have continued to play a role at various times throughout that planet's history in shaping its surface, even into the present time. At present, water is found in the polar caps, but a considerable inventory may reside in the subsurface, as permafrost, and perhaps liquid water beneath. Recent analyses of thermal neutrons (Feldman et al, 2003) indicate a large region of shallow, high water content in the topsoil. But is there substantial water at depth? Clifford (1993) presented an argument for a global Martian water cycle, with basal melting at polar cap bases providing liquid water that infiltrates the subsurface and slowly migrates to the equatorial region, where it can exit through the dessicated surface and then return to the poles via atmospheric transport. Total water inventory and transit time through a Martian hydrologic cycle are still very uncertain. Numerical modeling can be useful in refining qualitative ideas, providing sensitivities, and bringing together into one dynamically consistent quantitative process various kinds of information. A 3-D numerical model of porous flow and transport, previously developed to study possible modes of hydrothermal circulation beneath permafrost under Martian conditions (Travis, Rosenberg, \& Cuzzi, 2003) has been extended to include unsaturated conditions and vapor transport. It is applied to estimate possible subsurface water and permafrost distributions on Mars for a range of postulated water inventories. Travel times through a hydrologic cycle can be predicted as well.
DE: 1823 Frozen ground
DE: 1829 Groundwater hydrology
DE: 1875 Unsaturated zone
DE: 3230 Numerical solutions
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting