BBC News | SCI/TECH | Giant wave could threaten US
BBC News: Giant wave could threaten US -- "put it this way: if I was living in Miami or New York and I heard that the Cumbre Vieja was erupting, I would keep a very close eye on the news."
The wave would be caused by the side of a volcano collapsing during an eruption and hitting the Altantic ocean.
Have you seen Deep Impact? Sounds like it'd be something like that.