Fresh Tiger Stripes on Saturn's Enceladus

Do underground oceans vent through the tiger stripes on Saturn's moon Enceladus?
Long features dubbed tiger stripes are known to be spewing ice from the moon's icy
interior into space, creating a cloud of fine ice particles over the moon's South Pole
and creating Saturn's mysterious E-ring. Evidence for this has come from the robot
Cassini spacecraft now orbiting Saturn. Pictured above, a high resolution image of
Enceladus is shown from a close flyby. The unusual surface features dubbed tiger
stripes are visible in false-color blue. Why Enceladus is active remains a mystery,
as the neighboring moon Mimas, approximately the same size, appears quite dead.
Most recently, an analysis of dust captured by Cassini found evidence for sodium
as expected in a deep salty ocean. Conversely however, recent Earth-based
observations of ice ejected by Enceladus into Saturn's E-Ring showed no evidence
of the expected sodium. Such research is particularly interesting since such an ocean
would be a candidate to contain life.