A new study of a 2017 North Korean nuclear test determined the blast was probably about two-thirds more powerful than U.S. officials previously thought — and 16 times the size of the bomb detonated over Hiroshima in 1945, the American Geophysical Union reported.
Earlier data put the yield somewhere between 30 and 300 kilotons, with U.S. intelligence agencies figuring 140 kilotons — topping a 2016 test by about an order of magnitude, AGU reported.
But a new look at seismological data suggests the blast was between 148 and 328 kilotons, and probably around 250 kilotons.
“In 2006, when there was this little rumble, many people were quite dismissive that North Korea had the technology to do this properly, but I think from the progression we’ve seen with the increases of yield, it’s been a very well-executed weapons development program,” Steven Gibbons, a geophysicist and a researcher unaffiliated with the new study, told AGU.
“When you got to 2017, there’s no question that this is an incredibly destructive weapon. Even at the lower end of this uncertain yield, it’s a horrific weapon.”
The research was published in the Journal of Geophysical Research: Solid Earth.
“The very early events looked like they didn’t work very well, because they were unusually small. And then in one year they jumped up to 250-ish kilotons,” Thorne Lay, a seismologist at the University of California Santa Cruz and an author of the new study, told AGU.
“The scary thing is that this was such a big device.”
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