Ramalho standing near the 2014/2015 eruptive vent in Fogo, Cape Verde (Photo : University of Bristol)
A new study reveals how a massive megatsunami crashed into the Cape Verde islands located in the northwest coast of Africa some 73,000 years ago.
Scientists believe that a tsunami was triggered by a large region of Fogo, which is a volcanic island that collapsed into the ocean. This eruption caused colossal waves as high as 300 feet that travelled 30 miles to reach Santiago island causing widespread destruction and damage.
When this wave finally reached Santiago, researchers estimated that the tsunami already reached an incredible height of 900 feet as it went over and swallowed a 600 foot cliff. Apart from this destructive tsunami height, the force of this wave have reeled in large boulders from below the cliff, where they were transported on top of a plateau, getting drifted by the wave, as scientists discovered them after thousands of years.
According to lead author of the study, Ricardo Ramalho from the University of Bristol, this theory can somehow explain how massive boulders mysteriously lie on a plateau in Santiago, where a very steep cliff ends as it was previously unclear how the boulders were transported to that elevation.
However, after Ramalho found the boulders in 2007, another team of researchers conducted a different study of how a massive tsunami ravaged the region but their study only documented a tsunami impact of relatively low levels, not exceeding the top region of the plateau.
Ramalho and team added further evidence that the nearby volcanic island of Fogo played a crucial role in this tsunami as the seafloor in the region revealed evidence of a massive rock avalanche due to the collapse that triggered a massive megatsunami.
This event has caused wide scientific debate as many argue how evidence for this unusual phenomenon could be considered as ambiguous. Another theory also suggests that even if Fogo suffered a major collapse after a volcano eruption, these may not have occurred all at the same time.
The team used cosmogenic methods to determine the age of the rocks, where the rocks weigh up to 700 tons, resting on top of the plateau. The results reveal that the rocks were dated during the same time the island of Fogo collapsed.
Scientists also did not want to cause widespread panic to the locals, as the results reveal that the volcanic islands can produce similar events in the future. This new study is published in the journal Science Advances.
