Desperately, millions of people try to flee the coasts. Not enough time. Three hours later, the tsunamis slow down as they near shore and rise. Disaster comes not as a single wall of water crashing down, but a inland trickle that in half an hour submerges some places half a mile deep in floods rushing at hundreds of miles per hour. The first wave is the worst, but over the next seven hours, several tsunamis bash into land.
Long Island is washed under.
Washington, D. C., is devastated. Portugal and Spain are badly hit. Hills presented his computer simulations of the tsunami damage from such an asteroid collision today at the American Astronomical Society. The impact would also throw debris up into the air, plunging the world into near darkness, and trigger cataclysmic volcanic eruptions. Underwater earthquakes and volcanic eruptions are the usual causes of tsunamis, also once called tidal waves.