HR: 0830h
AN: P11B-1044    [PDF]
TI: Numerical Simulations of Recently Observed Dark Streaks on Mars
AU: * Hier Majumder, C A
EM: cathy@msi.umn.edu
AF: University of Minnesota at Minneapolis, Dept. of Geology and Geophysics 310 Pillsbury Dr. SE, Minneapolis, MN 55455 United States
AU: * Hier Majumder, C A
EM: cathy@msi.umn.edu
AF: Los Alamos National Laboratory, EES-2/MS-T003, Los Alamos, NM 87545 United States
AU: * Hier Majumder, C A
EM: cathy@msi.umn.edu
AF: University of Minnesota at Minneapolis, Minnesota Supercomputing Institute 499 Walter Library 117 Pleasant St. SE, Minneapolis, MN 55455 United States
AU: Travis, B
EM: bjtravis@lanl.gov
AF: Los Alamos National Laboratory, EES-2/MS-T003, Los Alamos, NM 87545 United States
AB: Recently observed dark streaks on Mars appear to be formed by a flowing fluid, possibly originating from melting ice. These streaks have been seen to form in a matter of months. They are markedly different from dust devil streaks in that they are very straight rather than twisting and curly. The dark streaks also only appear in regions where the temperature is right at 275 K, the triple point of water on Mars. Two hypotheses (of several) for their formation are that lighter dust sticks to a wet surface or brines precipitate a light rock varnish. The purpose of our study is to use numerical models to determine if the patterns associated with these dark streaks can be produced by a fluid flowing from a point source. We have used a 2-D model for fluid flow in a sloping porous medium, using the Richard's approximation of partially saturated fluid flow. The model is calculated using the TRACR3D code with water as the fluid. Our models show patterns similar to the dark streak patterns seen on Mars. We have varied the strength of the fluid source, the slope of the terrain, and the strength of capillary pressure in the porous medium to explore the range of features seen in the dark streaks. We have examined both continous and finite time sources. In future work, we will look at the effect of dissolved CO$_2$ in the fluid along with using brines that may precipitate minerals.
DE: 1823 Frozen ground
DE: 1866 Soil moisture
DE: 1875 Unsaturated zone
DE: 3230 Numerical solutions
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting