"What is a mega-tsunami?
A mega-tsunami is simply a gigantic wave, one big enough to cross oceans and destroy cities. They can be thousands of feet high moving at supersonic speeds. They can be caused by huge meteors crashing into the ocean, or by massive landslides. No boat or building hit by a mega tsunami could survive. But now scientists believe that we could be sitting on a time bomb, that sooner or later one will destroy New York, Boston and Miami, and that nothing could stop it"
from said website
..................................just so you know