Even the largest tsunami ever wouldn't make it past the Appalacan Mountains, so I really don't know what they are thinking about there. My guess is that even our biggest nuclear weapons are puny compared to a modest earthquake, so the Taunami plan probably won't work very well.

I've read that the impactor that created the Chicxulub caused a megatsunami that washed over the Rocky Mountains, although I can't find the article now. Instead, I found one that talked about a tsunami 305 meters tall, and a wiki page about megatsunamis that talks about it being just 100 meters tall.

Interestingly, further down it claims that, had the impactor struck deep ocean, the tsunami would have been 4600 meters tall. That's about the straight-line distance from my home to my work.

Neat, and utterly horrifying: https://en.wikipedia.org/wiki/Megatsunami#List_of_megatsunam...