Scientists have found evidence of a prehistoric megatsunami whose 850-foot wave would have engulfed the Santiago Island. It was triggered by a volcanic collapse some 73,000 years ago, according to a new study published in the journal Science Advances. The megatsunami occurred when a 9,300-foot volcano on the island of Fogo collapse during an eruption, generating a giant wave.
Is a future megatsunami imminent?
Findings of the study may prompt the global community to re-evaluate the potential threat of catastrophic collapses near coastal communities. Researchers warned that a similar scary event could trigger another megatsunami in future. Ricardo Ramalho of Columbia University said such volcanic collapses don’t happen frequently, but you can’t rule out the possibility of a similar event.
Ricardo Ramalho and his colleagues were working on Santiago Island a few years ago. They spotted giant boulders about 2,000 feet inland at 650 feet above sea level. The boulders were bigger in size than delivery vans. An analysis revealed that the boulders were composed of marine rocks, while the surrounding rocks were of volcanic origin.
770-ton boulders were swept by megatsunami
Dr. Ramalho said these boulders, some as big as 770-ton, were swept uphill by a giant wave. They calculated the amount of energy it would take to move such massive rocks to estimate the size of the megatsunami wave. Then they measured isotopes of helium near the boulders’ surfaces to conclude that the rocks had been lying there for 73,000 years.
Scientists said the findings further demonstrate that flank collapses may indeed happen and trigger enormous tsunamis. Megatsunamis are “very low-frequency, very high impact events,” said Ramalho. And technology cannot prevent a megatsunami. We can only use technology to improve our resilience to such catastrophic events. We need to start thinking and planning how we can respond to such a crisis. What measures can be taken? He noted that many volcanic islands are located close to heavily-populated areas