[Saturnalia]

This happens to tie into a theory on disappearing ships/airplanes.
As the theory goes, a large quantity of gas rises from the sea floor, reducing the density of the air/water, causing the vehicle in question to visit Davey Jones' locker.
Not as cool as Atlantis/mermen/aliens/rabid pineapples but slightly more plausible.

[djf]

Check it out on Google. I saw it on Discovery channel, they brought up a bucket full of sediments from somewhere in the Caribbean, there were all these crystals in it, they put it into a flask with a glass tube, and as it heated up, they lit the flame. Pure methane. Something like two billion years worth.