The posted link, http://europa.la.asu.edu/, clearly implies a study of the moon Europa, but immediately opens with an old photo of Io.

Be that as it may, the study of planetary geology is still in its infancy, and any who claims to be a graduate of the course is, himself, still in his infancy. We have yet to have accomplished any geologic study of any celestial body not Earth, other than our own Moon, the surface of which has barely been scratched by human interaction.

There are no conclusions, merely guesses. I would personally guess that there is a vast ocean beneath the surface of Europa – but until research proves one way or the other, it remains a guess.

Dan