Texture and composition of Titan's equatorial region inferred from Cassini SAR inversion: Implications for aeolian transport at Saturn's largest moon

Abstract : Sand seas on Titan may reflect the present and past climatic conditions. Understanding the morphodynamics and physico-chemical properties of Titan's dunes is therefore essential for a better comprehension of the climatic and geological history of the largest Saturn's moon. We derived quantitatively surface properties (texture, composition) from the modelling of microwave backscattered signal and Monte-Carlo inversion of despeckled Cassini/SAR data over sand sea. We show that dunes and interdunes have significantly different physical properties. Dunes are globally more microwave absorbent than the interdunes. The inter-dunes present multi-scale roughness with a higher dielectric constant than the dunes. Considering the composition, the interdunes are in between the dunes and the radar bright inselbergs, suggesting the presence of a shallow layer of non-mobilized sediment in between the dunes. Additionally potential secondary bedforms, such as ripples and avalanches, may have been detected. Our findings strongly suggest that sand seas evolve under current multi-directional wind regimes. Consequently sediment inventory and climatic conditions are being re-evaluated.
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Submitted on : Tuesday, February 14, 2017 - 8:44:36 AM
Last modification on : Friday, April 5, 2019 - 8:24:13 PM

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Antoine Lucas, Sébastien Rodriguez, Florentin Lemonnier, Alice Le Gall, Cécile Ferrari, et al.. Texture and composition of Titan's equatorial region inferred from Cassini SAR inversion: Implications for aeolian transport at Saturn's largest moon. Earth and Planetary Science Letters, Elsevier, 2018, pp.to be submitted to EPSL journal. ⟨hal-01467037⟩

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