North Korea appears to have conducted a sixth nuclear test after a “man-made” tremor was detected in the country’s north, not far from the country’s Punggey-ri nuclear test site.
South Korea and Japan are gathering and analyzing data to confirm the test, which Japanese Minister Shinzo Abe said, if confirmed, would not be tolerated.
“If North Korea did indeed conduct a nuclear test, we absolutely cannot tolerate and must protest firmly. We will convene a National Security council meeting to gather and analyze the information,” Abe said in a live television broadcast.
South Korea is currently holding a National Security Council meeting to discuss the incident, presided by President Moon Jae-in, according to South Korea’s Presidential office.
Seismological data from the United States Geological Survey (USGS) showed that an explosion caused a 6.3-magnitude tremor in the country’s northeast.
South Korea’s Joint Chiefs of Staff said in a statement that the military had “detected a man-made earthquake near Punggye-ri and is analyzing whether it was a nuclear test.”
It also announced that the military has raised its alert status.
Japan Meteorological Agency also observed a magnitude-6.1 tremor in North Korea, which showed a different waveform from a natural quake around 12:31 p.m. local (11:31 p.m. ET).
North Korea’s weapons program has been progressing at a rapid pace under leader Kim Jong Un. This would be the first under the administration of US President Donald Trump.
The country tested two nuclear weapons last year, including one in September close to the country’s Foundation Day holiday.
Tensions between North Korea and the international community flared against last week after Pyongyang flew a missile over Japan. The United States and its allies responded by sending fighter jets and bombers over the Korean Peninsula in a so-called “show of force” operation.
The test comes just hours after the country released images of Kim inspecting what it said was a hydrogen bomb ready to be fitted atop a missile.
“We shouldn’t be surprised by the fact they had the test, but usually they spread it out a bit,” says Melissa Hanham, a senior research associate in the East Asia Nonproliferation Program (EANP) at the James Martin Center for Nonproliferation Studies.
If the current magnitude holds, it’s possible that the weapon tested Sunday was a thermonuclear device, but it’s impossible to say if it was the peanut-shaped object shown in the images released by North Korean state media, says Hanham.
“When you’re evaluating these explosions, you have to do it with a grain of salt because you’re trying to mold a mathematical equation to something that’s happening in the real world. And the equations can to grip on things like depth or the geology of the area, and we don’t know those kinds of facts,” she said.
Experts have said for months that another nuclear test was likely on the way, with satellite imagery revealing that a new tunnel had been dug earlier this year.
Independent nuclear experts told CNN that another test would likely be a way to increase the yield, or destructive power, of a weapon.
North Korea claimed that it set off a thermonuclear weapon during the September 2016 test, but experts said the data showed it was more likely boosted fission weapon. Thermonuclear weapons typically use a fission explosion to create a fusion reaction, which is far more powerful than a fission reaction.
“For months North Korea refrained from conducting a nuclear test and from launching missiles over Japan, even though that meant testing on highly lofted trajectories and launching satellites to the south rather than east, which is more efficient. It now seems to have decided to end that restrain,” said David Wright, the co-director of the Union of Concerned Scientists Global Security Program.
“While this is likely to make it more difficult for the US and its allies to pursue diplomacy, that remains the best of the options on the table for trying to reduce the level of tension and avoid a crisis.”