Pillow lava on Titan: expectations and constraints on cryovolcanic processes

Abstract

Titan offers a fascinating environment in which to consider cryovolcanic processes: the Cassini/Huygens mission offers prospects for revealing cryovolcanic landforms, which may differ substantially from those on the other icy satellites owing to the effect of Titan's dense atmosphere. Various aspects of possible cryovolcanism on Titan are investigated in an attempt to predict what might be discovered. The thermal and stress environment on Titan is considered, and likely eruption rates and styles investigated: it is found that volcanic landforms are likely to be small, and “ash” cones are unlikely under present atmospheric conditions on Titan. Cooling rates for likely cryomagmas are investigated, and the possibility of rapidly-quenched pillow lavas is pointed out. Heat flow considerations limit the present resurfacing rate to <2 × 10 −3 m yr −1: if atmospheric methane is buffered against photolysis by volcanic resupply, then the resurfacing rate is > 1.5 × 10 −5 m yr −1.