Re: Fossil water
Well, Antarctica does have an active volcano, so I wouldn't be surprised
if geothermal heating is involved in 'warming' that lake's waters.
Geothermal heating comes in different forms however; just think of Saturn's
moon, Enceladus.
That begs the question: If Lake Vostok has life (we'll find out soon), does Enceladus' subsurface water reservoir contain life as well?