HR: 16:20h
AN: P34A-01 INVITED [Abstracts]
TI: The Great Basin and Mojave Desert as a hydrological analog to the Martian highlands
AU: * Howard, A D
EM: ah6p@virginia.edu
AF: University of Virginia, Department of Environmental Sciences
P.O. Box 400123, Charlottesville, VA 22904-4123, United States
AU: Matsubara, Y
EM: ym9z@virginia.edu
AF: University of Virginia, Department of Environmental Sciences
P.O. Box 400123, Charlottesville, VA 22904-4123, United States
AB:
The western United States has numerous enclosed drainages caused by an arid climate in conjunction with
active tectonic deformation. The highlands of Mars likewise feature numerous enclosed depressions, although
the cause is primarily impact cratering rather than tectonics. During the early history of the red planet, these crater
basins behaved much like their terrestrial analog, featuring lakes which expanded and contracted depending
upon the water balance and channel systems whose degree of integration likewise waxed and waned with
climatic variations. The Great Basin hydrological analog is explored using a spatially-explicit routing model that
balances runoff and evaporation to predict the size and location of lakes and flows through the channel system
under both modern and Pleistocene conditions. The model is parameterized using a spatial database of modern
precipitation and elevation as well as regression estimates of runoff and evaporation as a function of
precipitation, mean annual temperature, elevation, and latitude. The model reproduces the modern distribution of
lakes as well as the extent of Pleistocene lakes (e.g., Bonneville, Lahontan, and Manly) under reasonable
changes in average runoff and lake evaporation. The hydrological model has been adapted to the Martian
highlands to explore the degree of drainage integration and location of lake basins as a function of the ratio of
lake evaporation to runoff depth. Comparison of the spatial distribution of valleys, basin overflows, and incision
depths permits the estimation of relative evaporation and runoff during early Martian history. Simulation modeling
of landform evolution also is used to explore differences in pattern of erosion and deposition on the Martian
highlands as a function of the evaporation/runoff ratio.
DE: 1825 Geomorphology: fluvial (1625)
DE: 5415 Erosion and weathering
DE: 5419 Hydrology and fluvial processes
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2007 Joint Assembly