There was a PBS special on just that subject and the possibility of a tsunami -- very scary and it will be catastrophic for the entire east coast destroying many many miles inland. It would make hurricane Sandy look like a walk in the park. Pray to god it does not happen
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"Canary Islands, Future
One group of scientists believes that conditions are ideal for a tsunami-producing landslide on the island of La Palma in the Canaries. The western flank of the island's active volcano has the potential to give way in a future eruption. If it did, a huge mass of rock weighing 500,000 million tons would fall into the Atlantic Ocean. Experts in Switzerland have simulated the potential effects of such a collapse. Their model shows that it could generate a wave capable of engulfing every port on the east coast of the U.S., which they believe may have happened during a similar tsunami 120,000 years ago"
Like global warming there are many scientist who believe it won't ever happen