"When you put a ton of seawater into a cubic kilometer of liquid rock, things are going to get bad fast," he says. He suspects the explosion was triggered by a sudden change in the subterranean plumbing, which caused seawater to flood in. As it rose from the sea, layers of liquid magma filled a network of chambers beneath it. Garvin says the island's formation also probably seeded its destruction.
"It was quite amazing to see that happen." "They weren't ash - they were solid rock, blown to bits," he says. Slayback says the blast was so massive it even appears to have taken chunks out of the older islands nearby. Hunga Tonga-Hunga Ha'apai was completely destroyed by Saturday's explosion, says Dan Slayback, a research scientist for NASA's Goddard, as well as Science Systems and Applications Inc. Layers of steam and ash eventually connected the island, known as Hunga Tonga-Hunga Ha'apai, to two much older islands on either side of it. In late 2014 and early 2015, along the rim of that caldera, volcanic activity built a platform that rose up out of the sea, creating a new island. "In this particular case, we don't know when, a kind of volcano with a big summit ring of hills and things formed," Garvin says. The islands that form Tonga lie along a subduction zone where one part of the Earth's crust dips under another, according to Garvin. The volcano behind the eruption had been the subject of study by the NASA team in the years running up to this explosive event. The extent of the damage to the island nation remains largely unknown. In the case of this latest event, Garvin says that he believes the worst may be over - at least for now.Īn aerial view of heavy ash fall on Jan. That massive 19th-century eruption killed thousands and released so much ash that it cast much of the region into darkness. "This might be the loudest eruption since Krakatau in 1883," Poland says. The blast was heard as far away as Alaska and was probably one of the loudest events to occur on Earth in over a century, according to Michael Poland, a geophysicist with the U.S.
That means the explosive force was more than 500 times as powerful as the nuclear bomb dropped on Hiroshima, Japan, at the end of World War II. "We come up with a number that's around 10 megatons of TNT equivalent," James Garvin, the chief scientist at NASA's Goddard Space Flight Center, told NPR. NASA researchers have an estimate of the power of a massive volcanic eruption that took place on Saturday near the island nation of Tonga. It was obliterated in a volcanic eruption that scientists estimate was 10 megatons in size. The island of Hunga Tonga-Hunga Ha'apai as imaged by the satellite company Maxar on Jan.