When 800-foot wave engulfed entire African island

New York, Oct 5: Scientists working off west Africa in Cape Verde islands have found evidence that the sudden collapse of a volcano tens of thousands of years ago generated a tsunami that dwarfed anything ever seen by humans. The researchers said an 800-foot wave engulfed an island more than 50 km away. The study could revive a simmering controversy over whether sudden giant collapses present a realistic hazard today around volcanic islands or even along more distant continental coasts. "Our point is that flank collapses can happen extremely fast and catastrophically and therefore are capable of triggering giant tsunamis," said lead author Ricardo Ramalho from Columbia University. "They probably don't happen very often. But we need to take this into account when we think about the hazard potential of these kinds of volcanic features," he said. The apparent collapse occurred some 73,000 years ago at the Fogo volcano, one of the world's largest and most active island volcanoes. Nowadays, it towers 2,829 metres (9,300 feet) above sea level, and erupts about every 20 years, most recently last year. Santiago island, where the wave apparently hit, is now home to some 250,000 people. A study on this appeared in the journal Science Advances.