The U.S. East Coast's biggest tsunami threat lurks just off the coast of New England, according to research presented Friday at the Seismological Society of America's annual meeting in Salt Lake City.
Over the past year there have been 12 small earthquakes at the edge of the continental shelf - about 170 miles east of Boston - with the most powerful being a magnitude 4 quake that occurred April 12, 2012, according to John Ebel, of Boston College's Weston Observatory, which analyzes earthquakes.
Ebel presented preliminary findings of his research Friday at the Seismological Society of America's annual meeting in Salt Lake City.
"We have to consider the possibility that there could be a Grand Banks-style earthquake in these areas and a tsunami that could affect the Northeast coast," Ebel said, according to e! Science News.
In 2012 several other earthquakes were detected on the edge of the Atlantic continental shelf of North America, with magnitudes between 2 and 3.5. These quakes occurred off the coast of southern Newfoundland and south of Cape Cod, as well as in the area of the April swarm. All of these areas have experienced other earthquake activity in the past few decades prior to 2012.
Tsunamis occur infrequently in the Atlantic Ocean, but Ebel warns says tectonic conditions in the Pacific and Indian Oceans make tsunamis more likely to occur in those regions. In 1929, a magnitude 7.2 earthquake off the coast of Newfoundland caused a tsunami to hit Canada, killing 27 people, destroying thousands of homes and cutting transatlantic communication lines.
Although it's only a guess, Ebel thinks the increased seismicity from New Jersey to Nova Scotia could be related to changes that have occurred since the last Ice Age. For instance, the crust is flexing, now that its heavy load of ice and glacial lakes have disappeared.
"As soon as you get away from the glaciers, you don't have seismicity, but it could be a coincidence," Ebel said.
