A new study suggests that a massive megatsunami occurred in the Cape Verde islands off the coast of Africa around 73,000 years ago.
According to the theory, the tsunami was triggered by a large part of the volcanic island of Fogo collapsing into the ocean. This produced waves as massive as 300 feet high, which travelled a distance of around 30 miles to Santiago Island, where it would have caused indescribable damage.
When the wave hit Santiago, scientists say it could have surged all the way over a 600-foot cliff, ultimately achieving the height of an astounding 900 feet. Not only that, but it could have scoured massive boulders from below, carrying them to the top of the plateau — where they would be found by scientists many thousands of years later.
The study – published in the journal Science Advances – followed questions lead researcher Ricardo Ramalho had about massive boulders on a plateau of Santiago, which ends in a very steep cliff. Ramalho, who was at Santiago in 2007, said it was unclear how the boulders got up there.
A few years later, a different team of scientists published a study suggesting that there may have been a massive tsunami in the area. Their study, however, only documented a tsunami that impacted fairly low levels, rather than the top of the plateau.
Adding to the evidence of the tsunami is that the nearby volcanic island of Fogo had partially collapsed. The seafloor in the area also shows evidence of a massive rock avalanche, which scientists think could have caused a massive megatsunami.
The idea of a megatsunami has generally been considered controversial, with scientific debates centering on ambiguous evidence for the phenomenon. An alternate theory suggests that while Fogo could have suffered a large collapse, it may not have happened all at once.
Ramalho's team used cosmogenic techniques to date how long the rocks, which weigh up to 700 tons, have been sitting up on the plateau. The results correlated with the time of Fogo's collapse.
The scientists also said that while they don't want to scare people, they think that there are volcanic islands that could theoretically produce similar events in the future.
Via: Washington Post
