QUANTIFYING THE ENVIRONMENTAL RESPONSE TO DEGLACIATION IN MARTIAN CRATERS

The present day climate of Mars has been delineated by a hyperarid, freezing cold climate conditions - as has been typical of the Late Amazonian period of Mars - with glacial periods controlled by variations in orbital parameters, primarily obliquity. As these orbital parameters change in tandem with one another, the corresponding oscillations in insolation geometry have led to variations in climate regimes of specific regions, depending on the region’s latitude. In the past ~5 million years, the mean value of obliquity of Mars has decreased from ~35° to the current ~25°, a change which is interpreted to cause glacial ice to move from the mid-latitudes of Mars to the polar regions, resulting in deglaciation of the midlatitudes. On Earth, environments that experience deglaciation are classified as undergoing a paraglacial period, in which the landscape is recovering from the effects of glaciation. This results in increased sediment transport rates and the formation of a diagnostic set of geologic features. On the surface of Mars, this diagnostic set of features are also formed after glaciers migrate away, including gullies, spatulate depressions, washboard terrain, and polygonal terrain. We mapped out the distribution of these paraglacial features within formerly glaciated craters using CTX and HiRISE data. Based on these maps, we quantified various characteristics of each feature, as well as identified the location, proximity, and orientation aspect of said features. We found that the spatial extent of paraglacial features increases with increasing crater diameter. The data collected supports the interpretation that glaciers are no longer active at the mid-latitudes, while paraglaciation remains the prominent system these environments have recently experienced. Since the extent of paraglaciation was not equal across the craters analyzed, paraglaciation is interpreted to experience regional variability. Implications for the constraining of past and present climatic systems on Mars will be gained by further assessing the extent of paraglaciation on the Red Planet.