Utilizing a mixture of satellite tv for pc and surface-based surveys, researchers calculated the explosive energy of the volcano primarily based on the quantity of rock that was eliminated in the course of the blast from the island of Hunga Tonga-Hunga Ha’apai the place it sits, the obvious top of the eruption cloud and a number of other different elements.
“This can be a preliminary estimate, however we predict the quantity of power launched by the eruption was equal to someplace between 4 to 18 megatons of TNT,” Jim Garvin, chief scientist at NASA’s Goddard House Flight Middle, instructed NASA’s Earth Observatory weblog. (One megaton is equal to 1 million tons of TNT).
That makes the Tonga eruption probably lots of of occasions extra explosive than the atomic bomb that america dropped on Hiroshima, Japan in August 1945, which is estimated to have exploded with 15 kilotons (15,000 tons) of power. It additionally makes Tonga probably the most highly effective volcanic eruption seen on Earth in additional than 30 years, for the reason that eruption of Mount Pinatubo in 1991.
A brand new class of eruption
The Tonga volcano erupted violently on Jan. 15, a number of weeks after a sequence of smaller eruptions in late December 2021 shook the uninhabited island of Hunga Tonga-Hunga Ha’apai. The now-obliterated island shaped the uppermost a part of a large underwater volcano, which rises 1.1 miles (1.8 kilometers) from the seafloor and spans 12 miles (20 km) throughout.
Garvin and his colleagues have been monitoring the Tonga volcano since 2015, when magma from the volcano pushed new land above the water’s floor, connecting the islands of Hunga Tonga and Hunga Ha’apai. Frequent eruptions are to be anticipated from volcanoes like this one, the place liquid water and scorching scorching magma usually are available contact, producing violent explosions of steam, Garvin mentioned. Such eruptions are often known as Surtseyan eruptions.
Nonetheless, the explosive Jan. 15 eruption — which despatched a column of steam rising midway to house — was way more violent than a typical Surtseyan eruption, Garvin mentioned. This violence could also be as a result of unusually great amount of water concerned.
“A few of my colleagues in volcanology suppose this sort of occasion deserves its personal designation,” Garvin mentioned. “For now, we’re unofficially calling it an ‘extremely Surtseyan’ eruption.”
Devastating because the eruption was, it’s nonetheless only a glimpse of what Earth’s strongest volcanoes are able to. For instance, researchers estimate that the 1980 Mount St. Helens eruption exploded with 24 megatons of power, whereas the 1883 Krakatoa eruption unleashed 200 megatons of power, in keeping with NASA.
Initially revealed on Stay Science.