LPL Colloquium: Dr. Timothy A. Goudge
Characterizing the Incision of Ancient Lake Outlet Canyons on Mars
Dr. Timothy A. Goudge
The University of Texas at Austin
Some of the best geologic evidence for liquid water on the ancient surface of Mars is a record of paleolake basins. More than 200 of these basins have an outlet canyon that drained the lake, which requires a transition from an originally enclosed topographic basin (typically defined by an impact crater) to an open lake hydrologically connected to the exterior terrain via incision of an outlet. In this talk I will present our analyses of the topography and geometry of martian paleolake outlet canyons to test between two endmember hypotheses for their origin – rapid outlet incision by catastrophic lake overflow flooding vs. gradual outlet incision from long-term outflow that balanced inflow to the lake. Included in this analysis is a comparison of our results to observations of breached lake basins on Earth to test whether observed geometric scaling relationships are consistent across the two planets. Finally, some of the largest valley systems on Mars have main stems that are paleolake outlet canyons, and I will also present work to examine how the martian landscape responded to the incision of these large canyons.
Host: Dr. Jack Holt