Titan's global geologic processes

Michael Malaska (1) , Rosaly M. C. Lopes (1) , Ashley Schoenfeld (1) , Samuel Birch (2) , Alexander Hayes (2) , David A. Williams (3) , Anezina Solomonidou (1) , Michael A. Janssen (1) , Alice Le Gall (4, 5) , Jason M. Soderblom (6) , Catherine Neish (7) , Elizabeth P. Turtle (8)

1 JPL - Jet Propulsion Laboratory
2 Department of Astronomy [Ithaca]
3 SESE - ASU School of Earth and Space Exploration
4 ESTER - LATMOS
5 PLANETO - LATMOS
6 MIT - Massachusetts Institute of Technology
7 Department of Earth Sciences [London, ON]
8 APL - Johns Hopkins University Applied Physics Laboratory [Laurel, MD]

We have mapped the Cassini SAR imaged areas of Saturn's moon Titan in order to determine the geological properties that modify the surface [1]. We used the SAR dataset for mapping, but incorporated data from radiometry, VIMS, ISS, and SARTopo for terrain unit determination. This work extends our analyses of the mid-latitude/equatorial Afekan Crater region [2] and in the southern and northern polar regions [3]. We placed Titan terrains into six broad terrain classes: craters, mountain/hummocky, labyrinth, plains, dunes, and lakes. We also extended the fluvial mapping done by Burr et al. [4], and defined areas as potential cryovolcanic features [5]. We found that hummocky/mountainous and labyrinth areas are the oldest units on Titan, and that lakes and dunes are among the youngest. Plains units are the largest unit in terms of surface area, followed by the dunes unit. Radiometry data suggest that most of Titan's surface is covered in high-emissivity materials, consistent with organic materials, with only minor exposures of low-emissivity materials that are consistent with water ice, primarily in the mountain and hummocky areas and crater rims and ejecta [6, 7]. From examination of terrain orientation, we find that landscape evolution in the mid-latitude and equatorial regions is driven by aeolian processes, while polar landscapes are shaped by fluvial, lacrustine, and possibly dissolution or volatilization processes involving cycling organic materials [3, 8]. Although important in deciphering Titan's terrain evolution, impact processes play a very minor role in the modification of Titan's landscape [9]. We find no evidence for large-scale aqueous cryovolcanic deposits.References: [1] Lopes, R.M.C. et al. (2010) Icarus, 205, 540–558. [2] Malaska, M.J. et al. (2016) Icarus, 270, 130–161. [3] Birch et al., in revision. [4] Burr et al. (2013) GSA Bulletin 125, 299–321. [5] Lopes et al. JGR: Planets, 118, 1–20. [6] Janssen et al., (2009) Icarus, 200, 222–239. [7] Janssen et al. (2016) Icarus, 270, 443–459. [8] Malaska et al. (2016) Icarus, 270, 183–196. [9] Neish et al., (2014) GRL, 42, 3746–3754.

Domaines: Planétologie et astrophysique de la terre [astro-ph.EP]

Michael Malaska, Rosaly M. C. Lopes, Ashley Schoenfeld, Samuel Birch, Alexander Hayes, et al.. Titan's global geologic processes. DPS 48 / EPSC 11 (Division for Planetary Sciences and the European Planetary Science Congress), Oct 2016, Pasadena, United States. ⟨insu-01389934⟩