Geomorphological map of the South Belet region of Titan: An exploration of Mid-Latitude-to-Pole transition zones
Abstract
We carried out detailed geomorphological mapping of Titan's mid-latitude region south of the Belet Sand Sea. We used radar data collected by Cassini's Synthetic Aperture Radar (SAR) as our basemap, supplemented by spectro-images from VIMS, images from ISS, SARtopo, and microwave emissivity datasets. We mapped at a scale of 1:800,000 in all areas of the South Belet region covered by SAR swaths, taking into consideration the 300 m/pixel resolution of the swaths. For the mid-latitudes, we have defined five broad classes of terrains following Malaska et al. (2016). These terrain classes are craters, hummocky/mountainous, labyrinth, plains, and dunes. We have found that the hummocky/mountainous terrains are the oldest, with a radiometric signature consistent with icy materials. Dunes are the youngest units and return a radiometric signature consistent with organic sediments. The South Belet region of Titan is primarily covered by the dune and plain units (specifically the undifferentiated plains) typical of the mid-latitudes (Malaska et al. 2016). Previous mapping efforts of the mid-latitude regions of Titan (Lopes et al. 2016; Malaska et al. 2016) have indicated that these regions are predominately modified and influenced by aeolian activities. A plain unit designated "scalloped plains" is prominently featured between the 50°S and 60°S latitudes of this region. In this area we also find a terrain unit (dark irregular plains) that has been interpreted as damp materials saturated with liquid hydrocarbons (Malaska et al 2016; Hayes et al. 2008). We also note a higher identification of fluvial channels starting at this latitude zone and extending poleward. We suggest that these features demark the transition zone between mid-latitude/equatorial aeolian-dominated processes and fluvial-dominated processes prevailing at the poles.References: Lopes, R.M.C., et al.: Icarus, 270, 162-182, 2016; Malaska, M., et al.: Icarus, 270, 130-161, 2016; Hayes, A. et al.: Geophys. Res. Lett. 35, L09204, 2008.