Huge boulders were discovered off the west coast of Africa hints at a possible megatsunami that might have occurred in ancient times according to a researchers.
Scientists claim that not all tsunamis are caused by earthquakes. Some of these natural occurring phenomenon are cause by landslides especially those that occur in submarine canyons as well as those on the flanks of volcanoes.
University of Bristol geologist and head of the research team Ricardo Ramalho said in a statement obtained by Christian Science Monitor, "These finds provide another line of evidence that volcanic flank collapses really can happen suddenly and catastrophically and trigger giant tsunamis, and so we should underestimate the hazard potential of these events. That is the threat they pose to our society."
Ramalho and his colleagues are currently focusing on a large boulders discovered on one of the islands of Cape Verde which is located off the west coast of Africa. The boulder was discovered 2,000 feet (610 meters) inland and it is situated about 650 feet (200 meters) above sea level. Some of the boulders discovered weighs as much as 770 tons and measures 25 feet (8 meters) wide.
According to The Guardian, an unexpected collapsed of a volcano may have triggered a megatsunami which created waves measuring up to 800 feet (240 meters) high. This massive tsunami have powerful waves that is capable of carrying these massive boulders and displace them far away from the coast.
The boulders did not match with the terrain where they were discovered. Scientists working on it claim that the boulders contain limestone and other rocks that are found on the island's shoreline. The composition of the boulders led the scientists to believe that the boulders were brought there after a megatsunami occurred on the island.
In order to date the exact age of the boulder and when the megatsunami occurred, scientists analyzed helium isotopes found on the boulders.