Dune Widths in Titan’s Belet Sand Sea Reveal Patterns in Dune Formation and Stability

Introduction: Eolian dune fields found within Ti-tan's equatorial region between +30° latitude cover approximately 15-17% of the moon's surface [1]. These dominantly linear dunes are similar in form, size, and radar reflectivity to the large dunes of the Namib, Saharan, Saudi Arabian, and Australian deserts [2][3]. Earth analog studies indicate that the presence of linear dunes suggests adequate sediment supply, sufficient wind, and minimal sediment loss through transport or trapping by liquids [2][4][5]. The direct interaction between Titan's atmosphere and surface has produced the particular dune morphology present today [2][6]. Analysis of parameters such as dune width and spacing has revealed important aspects of dune-forming processes , regional conditions and relative ages for Earth [7], Mars [13] and Titan [8]. These studies may also help us better understand the interplay between the surface and atmosphere, and to ultimately discover potential sediment sources and global transport pathways [7][13][8]. Within Titan's dune fields, studies of dune parameters have shown that greater dune width tends to correlate with low latitudes [3,8]. The relationship between dune width and sediment supply, however, is not as well understood on Titan [9]. In this study, we discuss results from new width and spacing data gathered from images of Titan from Cassini's Synthethic Aperture Radar (SAR), and implications of the geomorphologi-cal variation throughout one of Titan's major sand seas, Belet. Approach: To help further constrain the nature of Titan's sediment transport, we analyzed results from previous studies on dune width and spacing from Earth analogs, in particular the Namib and Australian deserts. In the Namib Sand Sea, the greatest dune width, and additionally sediment accumulation, is located near the center [10]. Conversely, the centers of the Australian sand seas are the locations of relatively narrow dunes, along with higher volumes of sediment [11]. Common to both these analogs is greater sediment volume towards the middle of the sand seas, which has also been seen on Titan [12]. Detailed analyses of width and spacing across the sand seas will help us determine the relationship between Titan's sand seas the Earth analogues. Our current study focuses on the Belet Sand Sea located on Titan's trailing hemisphere between-5° and-9° latitude, and 65° and 150° W longitude. [3] and [12]