http://www.physorg.com/news100967382.html
... it is the result of current flow between the bodies, like similar events in the solar system.
Close inspection of previously photographed "geysers" on Enceladus and Io show remarkable filamentary structure, which is a tell-tale of Birkeland currents, a key component of Plasma Cosmology.
In the plasma cosmology view, there does not need to be any internal heating or anomalous geological activity. The bodies may be as static as originally throught, yet still produce these "geysers" electrically.
-G