Gully Slopes and Discharges on Lyot Crater’s Central Peak

Introduction: Since the discovery of gullies on some crater slopes and valley walls [1], there have been several hypotheses put forth concerning their origin and formation [2-10]. This study focuses on gullies that are located on the central peak of Lyot crater located in the Northern Plains of Mars (50.4N, 29.3E). The gullies source between 150m and 750m below the top of the central peak. A previous study by Dickson and Head [11] of gullies on topographic highs used MOC images and MOLA profiles to observe several areas where gullies are present, concluding that they were the result of the melting of a snow pack that had been deposited on the topographic high. Here we study well defined gullies present on the central peak of the impact crater Lyot, an Amazonian-aged, multiring impact basin that is 215km in diameter. We use a high-resolution set of stereo images provided by the HiRISE camera on the Mars Reconnaissance Orbiter (MRO) to perform a thorough analysis of meter-scale gully features and present a high resolution set of slope profiles. We then use this detailed elevation data to determine discharge estimates for the two major gullies on Lyot’s central peak using methods formulated by Ikeda [12] and Kleinhans [13].