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E. R. Kraal, E. I. Ashpaug (UC - Santa Cruz), R. D. Lorenz (Lunar and Planetary Laboratory)
Geomorphic evidence of surface water on Mars has important implications for planetary surface evolution, as well as for the continuing exploration of the planet as future landing sites are selected. Here we present the initial results from forward models of crater lake basin evolution motivated by the identification of intracrater landforms on Mars which exhibit possible evidence for a history of surface water. Proposed lacustrine Martian landforms include shorelines, terraces, and wave cut benches – features that have received considerable attention in terrestrial lacustrine geomorphology but which have never been quantitatively addressed with sufficient rigor on Mars. In particular, the existing body of terrestrial research has yet to be applied adequately to planets of different gravity, temperature (or working fluid) and atmospheric pressure, such as Mars and Titan.
The 2-D model includes wave generation, shore erosion, and other factors. Wave generation depends primarily on wind speed and basin size. The erosive power of the generated waves along the shoreline depends on wave size and period, initial topography, rock hardness, and the effects of crater impact formation on the bedrock. Other factors include water loss to evaporation and infiltration, sediment transport within the basin, wind transported sediment, and ice cover. Waves are generated using terrestrial empirical equations that have been modified for the lower gravity on Mars. Erosion is based on equations for terrestrial rocky coastline evolution models that have been modified for Martian conditions. Results presented here will focus on the first two aspects, wave generation and shoreline erosion. Additional research will include exploring the effect of different air pressures on the system as well as modifying the model for application to possible crater lakes of liquid hydrocarbons on Titan.
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Bulletin of the American Astronomical Society, 35 #4
© 2003. The American Astronomical Soceity.