HR: 0800h
AN: P41A-0886    [Abstracts]
TI: Water Vapor Diffusion Through Porous Regolith at Mars Environments
AU: * Hudson, T L
EM: thudson@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 United States
AU: Aharonson, O
EM: oa@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 United States
AU: Schorghofer, N
EM: norbert@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 United States
AU: Hecht, M H
EM: Mike.H.Hecht@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Bridges, N
EM: Nathan.T.Bridges@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Green, J R
EM: Jacklyn.R.Green@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AB: Water vapor diffusion is measured through porous media at Mars-like conditions and diffusion coefficients are obtained. A series of homogeneous porous glass disks exhibiting a range of pore sizes (10 to 220 microns) and thicknesses (0.25 to 8 cm) are used in initial experiments to validate the experimental setup and develop a system model. Correction factors to diffusion coefficients for gas-gas diffusion for this experimental geometry are obtained and applied to further samples. The values of porosity and grain/pore size studied cover the range of reasonable physical properties for near-surface Martian regolith. The diffusion coefficients for porous disks and unconsolidated Mars analog materials studied all fall within the range 5 to 15 cm$^2$s$^{-1}$, consistent with theoretical models. Calculated values of tortuosity factor also fall in the expected range of 2 to 5. Implications for ground-ice stability and equilibrium with the Martian climate are presented in the context of previous theoretical investigations.
DE: 5460 Physical properties of materials
DE: 5470 Surface materials and properties
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting