Colloquium: Andrew Dombard

Abstract: Jupiter's moon Europa continues to fascinate because it is likely liquid water ocean covered by a relatively thin, possibly geologically active ice shell which makes this satellite a prime candidate for life elsewhere in our solar system.  Here, I explore the concept that Europa has active volcanic processes.  I start with Europa's icy surface, where I use thermomechanical simulations to evaluate models proposed for double ridges, the most ubiquitous landform on Europa.  All models fail to explain the observation of lithospheric flexure at some ridges, except for a cryovolcanic one with icy surface eruptions underlain by intrusion of a watery sill.  Next, I discuss how future missions can use gravity to explore whether there is true volcanism on the rocky surface that rests at the base of the ocean, because volcanism at this rock-water interface would greatly increase the likelihood of life in Europa.