The nuclear bomb of North Korea is much bigger than we thought

Scientists looking for a North 2017 The Korean nuclear test revealed that the explosion was probably about two-thirds more powerful than WE. the officials have already thought.

Previous data indicated a yield of between 30 and 300 kilotonnes; the WE. the intelligence community reported 140 kilotons. It was already the most powerful device tested by North Korea, far exceeding a 2016 test. But a new review of seismological data suggests that the explosion was between 148 and 328 kilotonnes, and probably around 250 kilotons .

This is the conclusion of a group of researchers from the University of California at Santa Cruz; the seismological observatory of Costa Rica; and elsewhere, as published Monday in the Journal of Geophysical Research: Solid Earth. The team combined the sound wave data recorded during the explosion with information on North Korean nuclear tests since 2006, and then incorporated them into models showing how sound would flow through various types of rocks at a depth estimated from 430 to 710 meters.

A 250-kiloton weapon would be about 16 times more powerful than the one that leveled Hiroshima. Detonated over Washington, DC, he reportedly destroyed virtually all inner-city residential structures and inflicted third-degree burns on everyone within three miles.

A visualization of data from NUKEMAP showing the effects of a 250-kiloton nuclear bomb on Washington, D.C.

Estimating the size of the bombs that North Korea is testing underground is not easy thing outside the country. The scheme does not disclose information such as the depth of the test sites, the density of the surrounding rock and soil, etc. External observers should consider seismic sound waves of the type used by governments to measure the size of earthquakes. (Tests of underground nuclear bombs produce direct and compressed waveforms, not those of natural earthquakes.) Scientists use data from teleseismic stations around the world that measure P waves, or primary waves. These are the initial waves that occur during earthquakes when two large tectonic plates slide one over the other. The P waves indicate the size of the S waves, or secondary, which overturn the buildings.

The North Korean test of 2017 produced an earthquake of magnitude 6.3. But the way you look at these data determines the conclusion you reach. The new research uses a statistical trick called "relative wave equalization procedure", essentially a bit of a deal, like removing static noise from an audio signal, to allow researchers to better calculate "two very loud explosions" recorded at several stations ". according to the paper.

Steven Gibbons, Geophysicist of the Norwegian Seismology Program Array and Verification of the Norwegian Seismic Test Ban Treaty, or NORSAR, who was not affiliated with the study, told the American Geophysical Union: "They modeled what thought would look for different yields and depths and solved what the signal would look like if you did not have to take it into account. wave back. The most impressive thing in the document for me is the similarity of these waveforms. That's what gives me the assurance that they've done a good job. "

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