At least in
Sweden, gravlax is sliced
salmon that has been
marinated in various spices as a way of
preservation, it's never
buried in the ground. Actually, you have to
be pretty
careful when
preparing gravlax and
deep-freeze
the fish for at least 24 hours to get rid of
bacteria that would
otherwise thrive. Compare with
sushi, which is also frozen
before (in fact, if you are doing
sushi at home and don't trust your
local
fish monger enough to eat his
salmon raw, you can use
gravlax instead).
Gravlax is really two words, 'grav' meaning 'grave' or 'tomb' and
'lax' meaning 'salmon'. See also snorlax.