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Project Progress

This project focuses on the early evolution of the Martian atmosphere, the interaction of geodynamic and hydrologic processes, and the possible role of seepage in channel development (with implications for subsurface water available to support life). Our research indicates that organic aerosols may have had a large influence on the climate of early Mars and hence habitability of the planet. Particle formation can occur at considerably lower CH₄-to-CO₂ ratios than predicted by photochemical models. Geophysical modeling of polar wander and internal dynamic processes of Mars has shown that features mapped as potential shorelines, which currently exhibit relief of up to 2 km, could indeed be paleoshorelines from large, vanished oceans. Modeling also suggests that some (or even many) of the Martian outburst floods may have been triggered by large impacts and that the resulting liquefaction provides a source of water and may form the chaotic terrain. In contrast, analysis of some of the landslide features in Valles Marineris indicates that these features were dry fall, rather than associated with water. We conducted field investigations in the Colorado Plateau and Hawaii at sites often cited as examples of seepage driven channel formation. Unexpectedly, we have concluded the case for seepage erosion of bedrock is unpersuasive. Detailed field research at a new site in which a spring headed channel has carved into the basalts of the Snake River Plain has shown subtle evidence that at least one major flood down the plain may be responsible for carving the canyon, rather sapping at the channel head. Key data at this site are exposure age dating of boulders to test whether the channel advanced progressively over 10’s of thousands of years or was essentially in an instant. Our findings here have important implications for the common assumptions about the role of seepage in cutting channels across the Martian surface.