Global contraction/expansion and polar lithospheric thinning on Titan from patterns of tectonism

• Published in: Journal of geophysical research. Planets 2015-06, Vol.120 (6), p.1220-1236
• Main Authors: Cook-Hallett, Casey, Barnes, Jason W., Kattenhorn, Simon A., Hurford, Terry, Radebaugh, Jani, Stiles, Bryan, Beuthe, Mikael
• Format: Article
• Language: English
• Subjects: Cassini mission; Deformation mechanisms; Equator; Equatorial regions; Evolution; global stress fields; Hills; Joining; Latitude; Lithosphere; Mapping; Moons; Mountains; Orientation; Plate tectonics; Polar environments; Polar regions; Poles; Radar; Radar data; Saturn; Saturn satellites; Solar system; Stresses; tectonics; Thinning; Titan
• ISSN: 2169-9097; 2169-9100
• DOI: 10.1002/2014JE004645

We investigate the underlying physical processes that govern the formation and evolution of Titan's tectonic features. This is done by mapping mountain chains and hills using Cassini RADAR data obtained during Titan flybys T3 to T69. Our mapping of mountain chains and hills reveals a global pattern: east‐west orientations within 30° of the equator and north‐south between 60° latitude and the poles. This result makes Titan one of the few solar system bodies where global processes, rather than regional processes, dominate tectonism. After comparison with five global stress models showing theoretical mountain chain orientations, we suggest that either global contraction coupled with spin‐up or global expansion coupled with despinning could explain our observations if coupled with a lithosphere thinner in Titan's polar regions. Key Points Global tectonism is evident as seen through the mapping of its mountains A global stress field is responsible for the deformation of Titan's ice shell Mountains are a result of either contraction/spin‐up or expansion/despinning