Tonga Volcano Eruption Was 500 Times More Powerful Than Hiroshima

Last weekend the Hunga-Tonga-Hunga-Ha'apai volcano, located just over 18 miles off the coast of Tonga's Fonuafo'ou Island, erupted. The resulting blast was so big, it sent many nations across the world scrambling over tsunami warnings. The same volcano also made headlines with a previous eruption in 2015 that resulted in the creation of small land formations. The new eruption in 2021 has added 50 percent more landmass to the volcano-made islets. However, the recent blast was so massive it destroyed most of the land formations nearby. 

Even though it has been four days since the eruption, the island nation of Tonga still remains cut off from the world with undersea communication cables cut and its airport covered in ash.

Just how strong was the blast?

A NASA team had been studying the volcano in question for years before the recent explosion. In an interview with NPR, James Garvin, the chief scientist at NASA's Goddard Space Flight Center, said that the islands that form Tonga lie along a subduction zone where one part of the Earth's crust dips under another. 

Regarding the eruption's power estimate, Garvin said that they came up with a number that's equivalent to around 10 megatons of TNT. If that didn't sound like a lot, 10 megatons of TNT is 500 times more powerful than the nuclear bomb dropped on Hiroshima, Japan, at the end of World War II. 

Aside from its explosive force, the eruption of Hunga Tonga-Hunga Ha'apai itself was relatively small and lasted less than 60 minutes, compared to other volcano eruptions in history, according to Michael Poland, a geophysicist with the U.S. Geological Survey, reports NPR. The blast was reportedly heard as far away as Alaska and was probably one of the loudest events to occur on earth in over a hundred years, but the real mystery is how such a relatively small eruption could create such a big bang and tsunami, says Poland.

In addition to the currently ongoing analysis of the satellite imagery and additional surveys, the team will be following the interesting volcanic activity around the volcano's caldera and nearby areas when it's safer to visit during the year.