Study indicates giant tsunami created by volcanic collapse may have overrun Cape Verde Islands in the past.
Tsunamis happen regularly in today’s world, and gigantic ones, while rare, have occurred during the last century. The largest ever recorded happened as a 1,724-foot-high wave, created by an earthquake and a 90 million-ton rock slide that fell into Alaska’s Lituya Bay, engulfed a corner of Alaska in 1958. Amazingly during that event, two fishermen were lifted atop the wave and carried over a forest, somehow living to tell about the adventure.
Open-ocean volcanoes are the main concern of the researchers and the point of the controversy. Some experts say the physics of waves created in the ocean would allow the waves to dissipate more rapidly and lose energy quickly, due to the amount of surface area to cover.
In the case of the Fogo tsunami, the giant wave would have had to travel about 34 miles across open ocean to reach the Cape Verde Islands. Some experts argue that the resulting wave created by the force of the collapsing volcano would have been significantly smaller by the time it reached the islands.
Still the evidence of the out-of-place boulders remains, as does the possibility of the giant 800-foot tsunami.
A tsunami expert with the University College London, Bill McGuire said, the research “provides robust evidence of megatsunami formation [and] confirms that when volcanoes collapse, they can do so extremely rapidly.”
McGuire, who was not involved in the Fogo study, adds his own work finds that megatsunamis happen maybe once in 10,000 years. But he cautioned, “Nonetheless, the scale of such events, as the Fogo study testifies, and their potentially devastating impact, makes them a clear and serious hazard in ocean basins that host active volcanoes.”
But even though the evidence seems to point to a mega-disaster that happened 73,000 years ago, there is no immediate cause for alarm. Volcanoes erupt and collapse around the world and the events, while may be catastrophic in the immediate area, will not necessarily cause the type of damage that may have occurred at the Cape Verde Islands.
Even Ramahlo advises people not to jump to a conclusion, saying, the Fogo event doesn’t mean every collapse happens catastrophically.
The results of the study were published in the journal Science Advances.