[x]

How common are these things? I learned about them as a kid, and maybe saw something on a PBS special since then, but haven't heard or seen the word used in years. If I remembered the word, I'd probably have associated it with science fiction, rather than with a real danger.

It seems like it would take a certain about of explaining to make clear to the public just what the danger was. Is this a case of scientists not quite being on the same wavelength as the public?

[syriacus]

How common are these things?

They do occur in that part of the world.

http://www.worldinfozone.com/facts.php?country=Bangladesh

In 1991 a tsunami wave killed one hundred and thirty-eight thousand people in Bangladesh.