Tsunami in Tonga Photograph:( AFP )
The Tonga volcanic eruption unleashed explosive forces that dwarfed the power of the Hiroshima atomic bomb, NASA scientists have said, as survivors on Monday described how the devastating Pacific blast "messed up our brains".
According to NASA, the volcanic eruption in Tonga unleashed explosive forces comparable to up to 30 million tonnes of TNT — hundreds of times more than the atomic bomb dropped on Hiroshima.
When Hunga Tonga-Hunga Ha'apai, an underwater volcano in the South Pacific, erupted on January 15, it shot debris as high as 25 miles into the skies.
It generated a 7.4-magnitude earthquake, which triggered tidal waves that slammed into the island, covering it in ash and cutting it off from outside assistance.
It blanketed the island kingdom of about 100,000 in a layer of toxic ash, poisoning drinking water, destroying crops and completely wiping out at least two villages.
According to the NASA Earth Observatory, it also emitted between 5 and 30 megatons (5 million to 30 million tonnes) of TNT equivalent.
In comparison, the US atomic bomb unleashed on Hiroshima, Japan, in August 1945 was estimated to have been around 15 kilotons (15,000 tonnes) of TNT.
Radar measurements conducted before and after last month's eruption reveal that only small portions of two Tongan islands — Hunga Tonga and Hunga Ha'apai — remain above the volcano.
Mount St. Helens exploded with 24 megatons of energy in 1980, while Krakatoa exploded with 200 megatons of energy in 1883, according to scientists.
The tremendous changes at Hunga Tonga-Hunga Ha'apai, the topmost section of a massive underwater volcano, are also visible on NASA Earth Observatory digital elevation maps.
(With inputs from agencies)