COLLEEN MCEDWARDS, WORLD NEWS: Pacific Rim countries are particularly vulnerable to tsunamis. That is Japanese for giant tidal waves, typically caused by seismic activity on the ocean floor. Now marine researchers say that tsunami risk has increased along the Mid- Atlantic coast of the United States. CNN's Natalie Pawelski reports.</s>NATALIE PAWELSKI, CNN CORRESPONDENT (voice-over): These pictures of disaster are from Papua New Guinea two years ago - entire villages wiped out, at least 1,500 dead from a tsunami, a towering wall of water striking land with virtually no notice. Researchers say there's a slight possibility that the mid-Atlantic coast of the United States could see a big wave of its own: not caused by a mid-ocean earthquake, like most tsunamis, but from sub-sea landslides.</s>JEFFREY WEISSEL, COLUMBIA UNIVERSITY: The calculations that we did, and have since been refined, show that the tsunami wave triggered by a submarine landslide out on the outer continental shelf would pack the same punch as a storm surge associated with a category 3 or 4 hurricane, which is a big hurricane, and would pose the same kind of danger to the people living along the coast.</s>PAWELSKI: A team of scientists just returned from a two-week trip to the edge of the continental shelf, about 60 miles east of Norfolk, Virginia. There they found evidence that pockets of gases beneath the sea floor could erupt, triggering landslides and sending a tsunami hurtling toward land. Beaches and beach towns could be hard-hit by a fast-moving wave as high as 20 feet. Places as far inland as Washington, D.C., could be flooded as bays and rivers back up from the tidal wave. But don't evacuate just yet. The scientists say that the last similar landslide is believed to have happened near the end of the Ice Age, more than 10,000 years ago. And they add, coastal residents are much more likely to be harmed by hurricanes than by any chance of a killer tidal wave. Natalie Pawelski, CNN.
Researchers Find Increased Risk For Tidal Wave On U.S. East  Coast