SURFACE CONDITIONS ON TITAN THROUGH A DUNE-PATTERN ANALYSIS (Invited Presentation)

Patterns formed by the crestlines of windblown sand dunes are visible from orbit on many planetary bodies of the Solar System. Despite wide-ranging boundary conditions (i.e., gravity, atmospheric pressure, sediment size and density, etc.) across those planetary surfaces, fields of sand dunes display consistent geometries, and the patterns they form evolve through the same maturation process. Under constant wind and sediment conditions, dune patterns “coarsen”, i.e., dune size increases and crestline geometries and orientations become more uniform. However, a perfect pattern, without any crestline defects, is unlikely to exist in nature, due to, e.g., the finite extent of dune fields or climate oscillations. Dune fields that recently experienced known changes in boundary conditions display elevated spatial densities of pattern defects. As a result, dune field patterns encode information about the field’s recent history of environmental conditions. First, we demonstrate how to decipher that information from an analysis of 46 dune fields on Earth and Mars from high-resolution satellite images. Second, we apply dune-pattern analysis to Titan. Titan’s equatorial dune fields present uniquely long and nearly continuous sediment transport pathways, minimizing the role of dune-field boundaries on dune-pattern statistics. As a result, dune-field pattern analysis may provide critical insights into wind and sediment conditions around Titan’s equatorial regions. Specifically, we use a database of over 30,000 digitized dune crests to investigate dune-pattern statistics across Titan’s four largest dune fields – Fensal, Senkyo, Belet, and Shangri-La. Our findings highlight that the radar-bright Xanadu region interrupts dune-pattern maturation and exerts a strong control on the dune-fields’ boundary conditions. At the conference, we will discuss the possible influence of Xanadu on sediment supply and availability.