The Role of Seasonal Sediment Transport and Sintering in Shaping Titan's Landscapes: A Hypothesis

Titan is a sedimentary world, with lakes, rivers, canyons, fans, dissected plateaux, and sand dunes. Sediments on Saturn's moon are thought to largely consist of mechanically weak organic grains, prone to rapid abrasion into dust. Yet, Titan's equatorial dunes have likely been active for 10s-100s kyr. Sustaining Titan's dunes over geologic timescales requires a mechanism that produces sand-sized particles at equatorial latitudes. We explore the hypothesis that a combination of abrasion, when grains are transported by winds or methane rivers, and sintering, when they are at rest, could produce sand grains that maintain an equilibrium size. Our model demonstrates that seasonal sediment transport may produce sand under Titan's surface conditions and could explain the latitudinal zonation of Titan's landscapes. Our findings support the hypothesis of global, source-to-sink sedimentary pathways on Titan, driven by seasons, and mediated by episodic abrasion and sintering of organic sand by rivers and winds.

Automated summary

Titan, Saturn's moon, has various sedimentary features including dunes, lakes, rivers, and plateaus. This study explores the mechanism of sand particle formation on Titan's equatorial dunes over long periods of time. The findings suggest that seasonal sediment transport, along with episodic abrasion and sintering by rivers and winds, can explain the formation and maintenance of sand grains on Titan.