The size — and deadly consequences — of the Hunga Tonga-Hunga Ha'apai eruption that occurred last week has now begun to be quantified, with scientists estimating the power of the eruption, which satellites caught creating ripples in the atmosphere. According to local officials, the eruption had a radius of 260 kilometers (161.5 miles), and threw up ash 20 kilometers (12.4 miles) into the atmosphere, releasing massive amounts of energy.
James Garvin, chief scientist at NASA's Goddard Space Flight Center, told NPR that the eruption released an equivalent of 10 megatons of TNT, making it one of the most powerful eruptions in 30 years. Back in June 1991, the eruption of Mount Pinatubo in the Philippines released about 20 times more thermal energy than the Hunga Tonga-Hunga Ha'apai event.
It is difficult to visualize such an incredible release of energy. It is equivalent to more than 500 times the atomic bomb the US dropped on Hiroshima in 1945, killing over 90,000 people, and it's 9,000 times more energetic than the explosion that took place in the harbor of Beirut in 2020, which cost the lives of 210 people and injured several thousand.
The volcano was underwater and had been experiencing a period of increased activity over the last month. On its summit, the inhibited island of Hunga Tonga-Hunga Ha'apai appeared as two islands, which merged in 2009, and are now once again separate due to this recent event.
The eruption was surprisingly quick, and scientists are currently investigating how the eruption generated such a powerful tsunami, which spread throughout the Pacific, since tsunamis are usually caused by earthquakes rather than by submarine volcanos.
The situation in Tonga in terms of death and devastation remains uncertain, though three are confirmed dead and several people are still missing. A submarine telecommunication and internet cable was damaged during the eruption, which has led to severely limited communication to and from the Pacific Kingdom. However, initial flights by planes from New Zealand suggest dozens of homes have been destroyed after some of the 36 inhabited islands were flooded by the powerful wave. They are now having to contend with the ash layer deposited by the eruption, which has affected flights and fresh drinking water.
Elsewhere the tsunami caused the death of two women in Peru, 10,000 kilometers (6,100 miles) away, and reached Samoa, Japan, Australia, Hawaii, New Zealand, and Chile.
While communications are being restored, the Tonga government is working on a plan for prioritizing aid as well as protecting its 100,000 people, as the country is COVID-free and there is concern aid workers may bring the virus.