Evidence that a volcano making approximately 2.8 km in height on Fogo Island once collapsed following eruption, thereby unleashing a giant tsunami, has recently been documented in a paper published in the journal Science Advances. If it really happened, it only happened in the distant past, around 73,000 years ago. However, the researchers mention the possibility that such an event might happen again. Uh-oh. Humanity is ever so vulnerable in the face of natural calamities, is it not?
A massive tsunami was triggered on the island of Fogo in the aftermath of a landslide. Photo credits: NASA.
The giant volcano on the island of Fogo is one of the world’s greatest and most active volcanoes. The study describes the event that occurred thousands of years ago when it is said to have generated an enormous wave when it collapsed during an eruption. The tsunami that was thus generated appears to have crashed near to Santiago Island.
If this image of something that happened very long ago posing no direct threat to us is not scary enough, imagine an event of such a spectacular scale occurring NOW. Collapsing volcanoes are not necessarily restricted to the old times.
“Our observations therefore further demonstrate that flank collapses may indeed catastrophically happen and are capable of triggering tsunamis of enormous height and energy, adding to their hazard potential,” write the scientists.
The occurrence might be rare, but the researchers believe it should be taken into consideration.
“Our point is that flank collapses can happen extremely fast and catastrophically, and therefore are capable of triggering giant tsunamis,” says lead author, Ricardo Ramalho, an adjunct scientist at Columbia University’s Lamont-Doherty Earth Observatory, in a statement. “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.”
The researchers came to their conclusion after they came across huge boulders (as large as vans) at nearly 200 metres above sea level. They later discovered that they matched the rocks lining the shoreline of the island. According to them, a giant wave lifted the gigantic rocks, carrying them uphill. When they calculated the energy requirement to do so, they realised it was an extremely massive wave.
Thereafter, the researchers measured isotopes of helium found near the boulders’ surface and determined that the rocks had been moved to the open location around 73,000 years ago.
However, it is to be noted that their theory is viewed with scepticism from other scientists who find it hard to digest that volcanoes would suddenly collapse and generate great tsunamis.
On the other hand, the researchers are only mentioning the possibility of such an event.
“It doesn’t mean every collapse happens catastrophically,” Ramalho said. “But it’s maybe not as rare as we thought.”