Cryomagmatic and tectonic processes in Europa's ice shell

Liquid water is more dense than ice so its eruption onto the surface of icy satellites, such as Europa, is not expected. I will describe some mechanisms that might allow liquid water to erupt. If liquid does not reach the surface, if may be injected into the ice shell that encases these satellites. The surface of Europa is littered with quasi-elliptical features a few to a few tens of kilometers in diameter that may be the product of intrusions of liquid water. I will compare model predictions with observations. Europa’s surface also contains numerous tectonic features that show evidence of extension of the surface. A long standing paradox is that there is no apparent corresponding contraction. Mapping of the surface allows us to identify where some of the missing contraction is accommodated.