HIDING TITAN OCEAN - DENSIFICATION AND HYDROCARBON STORAGE IN AN ICY REGOLITH

The problem of regolith densification is examined with application to Titan, with the objective of establishing the pore volume in the regol ith. A large pore volume could store the large volume of hydro-carbons required to exist on Titan's surface by photochemical models, forming a ''buried ocean'', a surface model more compatible with observationa l constraints than the global ocean model favored in the last decade. A sophisticated coupled model of methane diffusion and regolith densif ication is presented. It is found that several hundred meters equivale nt ''ocean'' depth can be concealed in the regolith. Further, methane diffusion through the regolith is fast enough to maintain the atmosphe ric methane concentration against photolysis. ''Hydrothermal'' methane circulation may play a significant role in surface chemistry and tran sport. Copyright (C) 1996 Elsevier Science Ltd