El Hierro is situated in the most southwestern extreme of the Canaries. The island was formed after three successive eruptions. Volcanic activity, principally at the convergence of the three ridges, has resulted in the continual expansion of the island.
A mere 50,000 years ago, as a result of seismic tremors which produced massive landslides, a giant piece of the island cracked off, crashed down into the ocean and scattered along the seabed. This landslide of more than 300km3 gave rise to the impressive amphitheatre of the El Golfo valley and at the same time caused a tsunami that most likely rose over 100 metres high (300 feet) and probably reached as far as the American coast.
If there's a repeat of what it did 50,000 years ago, it's going to ruin a hundred or so million residents of the East Coast's day. To read the rest of the article, click here.