During the Ice Age, the Gulf Of Mexico became isolated from the worlds oceans by a 'dam' across Florida, Cuba and the Yucatan. Over time, the Gulf dried up some to a reduced, but stable, lower body of water. The Atlantaians weren't aware that anything was unusual and built a magnificent city on the Gulf coast, 2200 feet below the present water level.
Now, when the asteroid crashed into the 'dam' it ignited the volcanos on Cuba and reflooded the whole Gulf Of Mexico up to it's current level. The heat from the asteroid and the volcanos burned the forests and then the waters quickly cascaded in and covered them and the wonderful city of Atlantis.
In my next post, if you'll look around the Bahamas on the map that I'll link, you'll see underwater impact craters from the asteroid swarm that broke the 'dam.'
Notice that the Red Sea is landlocked, there is no Persian Gulf and etc.
