Cryovolcanism and Degassing Processes on Titan, Saturn's Satellite
The paper considers the distribution, diversity and features of volcanic and degassing processes on Titan, and also analyzes the maximum gas concentrations of volatile compounds along the vertical profile of its interior and atmosphere. It is shown that the specificity of volcanic and degassing processes on Titan is due to low temperatures, a peculiar material composition and the widespread distribution of the subsurface liquid horizon. As a result, the usual (for the Earth) forms of (cryo-)volcanic activity are reduced here, while widespread 1) “gas-lifting degassing”, which forms numerous small depressions with an increased liquid level and, possibly, is the cause of the appearance of “magic islands” in the Ligeia Mare, as well as 2) limnological emissions of gaseous methane, followed by intense cloud formation, the development of methane storms and the fallout of large volumes of precipitation. In turn, both gas-lifting degassing and limnological emissions of endogenous methane are caused by the “condensate → gas” inversion at depths of 1–2 km in the bowels of Titan. Below this level, endogenous fluids are represented by practically gas-free condensates, while above this, their intense boiling begins. It was concluded that degassing processes are the most important relief-forming factor on Titan.