I want to elaborate on Jeremy’s mention of the “tsunami drill”. Here’s some background information…mainly so we don’t needlessly scare the bejeebers out of anybody.

Tsunamis are considered to be very, very rare for the east coast of the U.S. Usually, they’re caused by undersea earthquakes…and since we’re nowhere near any active fault line, that seriously limits our vulnerability. However, that is not to say that a tsunami is entirely impossible.

A major seismic event in the Caribbean or all the way across the Atlantic could possibly spread a tsunami wave to America. Of special concern is Las Palmas, a volcanic island in the Canaries, off North Africa. An volcanic eruption there could send a large part of that island tumbling into the sea, creating waves that could pound the entire Eastern Seaboard, as well as much of the South American, Caribbean and European coasts. It has been estimated that such a tsunami would take about 7 hours to reach U.S. shores.

Another possible tsunami threat might come from directly off our coastline…the eons of organic muck descending into the depths off the Continental Shelf. The shelf here abruptly drops off to the abyssal plain three miles below. If any large portion of that sloping area of mud shifts and slides downward (slumps), there could be a huge displacement of mass. In other words, a gigantic undersea mudslide could cause an even more gigantic mass of water to shift…creating a tsunami. Some 18,000 years ago, about 33 cubic miles of the cliff collapsed. The event created a series of huge waves that left geological evidence across the Carolina and Georgia “Low Country.”

From what I can find, there have been two contemporary tsunami events along North America’s east coast. On October 28th, 2008, a series of 4 to 12 foot waves crashed ashore at Boothbay Harbor, Maine. This was likely an example of undersea “slump”. The waves hit at low tide, thus saving the town, but destroying piers and boats in the harbor. In 1929, a 90 foot “tidal wave” set off by a magnitude 7.2 undersea earthquake inundated the Nova Scotia and Newfoundland shores. Dozens of people were killed. This tsunami was far closer to a seismically-active region.

So while an East Coast tsunami is highly unlikely in any of our lifetimes, it isn’t out of the question. Given the huge population on America’s Atlantic Seaboard, it does seem prudent to have a series of early warning buoys out there.