Comparison of Titan's north polar lakes with terrestrial analogs

Abstract

.[1] The discovery of hydrocarbon lakes in the polar regions of Titan offers a unique opportunity to compare terrestrial lakes with those in an extraterrestrial setting. We selected 114 terrestrial lakes formed by different processes as analogs for comparison with the 190 Titanian lakes that we had mapped in our previous study. Using the Shuttle Radar Topography Mission (SRTM) C-band backscatter data and the SRTM Water Body Data (SWBD), we carried out an assessment of manual mapping versus existing automated mapping techniques, and found the automated techniques to produce as good representations of the lake shorelines as the manual mapping in the terrestrial dataset. We then calculated and compared terrestrial and Titanian shoreline statistical parameters including fractal dimension, shoreline development index and an elongation index. We found different lake generation mechanisms on Earth produce "statistically different" shorelines. However, we cannot identify any one mechanism or set of mechanisms to be responsible for forming the depressions enclosing the lakes on Titan, on the basis of our statistical analyses.

Lake shoreline in the contiguous United States: quantity, distribution and sensitivity to observation resolution

“…Despite sensitivity to resolution, most estimates of lake perimeter in previous studies (e.g. Kent & Wong, ; Riera et al ., ; Sharma & Byrne, ) were measured using maps at similar or coarser resolutions than this study, meaning their perimeter estimates would fall between P obs and P min presented here.…”

A global inventory of lakes based on high-resolution satellite imagery

“…Such processes, currently estimated based on less well‐constrained information on lake abundance, include emission of carbon dioxide [ Raymond et al ., ] and methane [ Bastviken et al ., ], sediment burial of carbon and other elements [ Einsele et al ., ], and primary production [ Lewis , ]. These results may also be a valuable for comparing to lakes on other planetary bodies such as Mars or Titan [ Seekell and Pace , ; Sharma and Byrne , ]. Because differences in size distributions or in fractal dimensions may correspond to the influences of different hydrologic regimes, geometric constraints, or geomorphic processes, such comparisons with Earth are one of the best ways to make inferences about the physical processes that have shaped the surfaces of other planetary bodies [e.g., Zhang et al ., ; Sharma and Byrne , ; Seekell et al ., ].…”

“…These results may also be a valuable for comparing to lakes on other planetary bodies such as Mars or Titan [ Seekell and Pace , ; Sharma and Byrne , ]. Because differences in size distributions or in fractal dimensions may correspond to the influences of different hydrologic regimes, geometric constraints, or geomorphic processes, such comparisons with Earth are one of the best ways to make inferences about the physical processes that have shaped the surfaces of other planetary bodies [e.g., Zhang et al ., ; Sharma and Byrne , ; Seekell et al ., ].…”

Estimates of fluvial erosion on Titan from sinuosity of lake shorelines

“…[], drawing an analogy to lakes in semiarid regions on Earth, additionally suggest that the margins of Ontario Lacus could have been modified by dissolution, though the solubility of Titan's surface materials in hydrocarbons remains uncertain [ Lorenz and Lunine , ]. Sharma and Byrne [, ] compared lake shapes on Titan and Earth, as measured by fractal dimension, shoreline development index (the ratio of the shoreline perimeter to the circumference of a circle with the same area), and an elongation factor, in an effort to identify the geological processes that formed Titan's lakes. Although they determined that certain formation mechanisms do produce statistically distinct shapes on Earth, they found that Titan's distribution of lake shapes is consistent with multiple formation mechanisms.…”