Evolution of Titan’s Coastlines

River deltas - which develop through the interaction of erosion, sediment transport, river flow, waves, tides, and sea level variations - are sedimentary archives that record past surface conditions, making them attractive targets for planetary exploration. Deltas have tentatively been identified on Saturn’s moon Titan, but they appear to be rare. Simply, many coastal rivers on Earth terminate in deltas, whereas on Titan most do not. 

Possible solutions to the question of Titan’s apparent missing deltas fall into two main categories: (1) deltas like those we see on Earth do not form (or rarely form) on Titan because of differences in materials, dynamics, and coastal conditions between the two worlds, or (2) there are many deltas on Titan, but the characteristics of the deltas and of Cassini datasets make them difficult to identify - Titan’s deltas may simply “look” different. Deciphering between these two endmembers, and decoding Titan’s record of tectonics, erosion and climate, requires an investigation of the processes that occur when rivers enter Titan’s lakes and seas and a re-evaluation of Cassini data for evidence of the resulting landforms. 

In this talk I will detail the combined theoretical, experimental and numerical approach we have undertaken to understand Titan’s coastal landscapes. Further, I will discuss how yet more applications of terrestrial quantitative methods to Titan’s environment should better allow us to decode Titan’s record of tectonics, erosion and climate, how we can use Titan to reveal new information about our own planet, and why such studies are critical as we transition out of Cassini’s era and into the era of Dragonfly.

Speaker: Sam Birch, Brown University