East Coast at Risk for a Tsunami: Earthquake Swarm May Herald Larger Threat

Tsunamis can cause massive amounts of destruction, so it's not surprising that scientists are interested in calculating the risk for one along the U.S. east coast. Now, researchers have announced the potential for an East Coast tsunami, and what series of events would lead to its creation.

Tsunamis are caused when a massive wave of energy is suddenly introduced into water, either due to a shift in the sea floor, landslides or volcanic activity. The largest tsunamis are often caused by earthquakes when continental plates shift and send a wave of energy through the water. This wave of energy can travel for miles before reaching land. Although the wave itself may only appear a few inches high in the open ocean, it grows quickly when the bottom of the sea begins to become shallow; there's nowhere for the energy to go but up. This, in turn, can cause a mass of water to push onshore and swamp coastal areas.

Interest in tsunamis has grown in recent years--especially when it comes to the East Coast.  In 2012, an earthquake "swarm" occurred offshore about 170 miles east of Boston. The largest earthquake among the 15 that occurred was a magnitude 4.0. While it's a known fact that earthquakes can cause tsunamis, scientists have been unsure whether conditions could necessarily precipitate an East Coast tsunami.

That said, the recent earthquake activity is similar to that of the M7.3 Grand Banks earthquake in 1929. The massive Canadian quake actually triggered a 34-foot-tall tsunami that crashed ashore along southern Newfoundland. It destroyed buildings and left tens of thousands of residents homeless.

So what did the researchers find in this case? The preliminary results suggest that an earthquake-triggered tsunami could indeed affect the northeast coast of the U.S. under the right conditions. The tectonic settings off of the coast of the U.S. are actually quite similar to the ones that triggered the Canadian earthquake in 1929. What is perhaps more disturbing is the fact that smaller quakes off of the coast of New Jersey likely are forewarnings of a larger earthquake that will occur in the future, according to LiveScience. These findings could allow officials better prepare for the potential of such a disaster.

The findings were announced at the Seismological Society of America 2013 Annual Meeting.