The blast is not consistent with an earthquake, said one expert: ‘It is … what you would expect with a nuclear explosive test.’
A senior State Department official released additional evidence on Feb. 17 in support of U.S. allegations that China conducted an underground nuclear test in June 2020, as global arms control frameworks unravel.
Assistant Secretary of State Christopher Yeaw, while speaking to a Hudson Institute meeting, discussed data from a remote seismic station in Kazakhstan that recorded a magnitude 2.75 “explosion” approximately 450 miles from China’s Lop Nur test grounds on June 22, 2020.
“I’ve looked at additional data since then. There is very little possibility I would say that it is anything but an explosion, a singular explosion,” said Yeaw, a former intelligence analyst and defense official who holds a doctorate in nuclear engineering.
“It’s also entirely not consistent with an earthquake. It is … what you would expect with a nuclear explosive test.”
Yeaw claimed that China tried to hide the event through decoupling, detonating the device in a spacious underground cavity to diminish seismic waves.
Under Secretary of State for Arms Control Thomas DiNanno earlier this month accused China of performing such secretive nuclear arms tests and implementing measures to restrict seismic evidence.
“Today, I can reveal that the U.S. Government is aware that China has conducted nuclear explosive tests, including preparing for tests with designated yields in the hundreds of tons,” DiNanno said.
These claims back up Yeaw’s assertions of concealment tactics.
The Comprehensive Nuclear-Test-Ban Treaty Organization, which monitors global explosions, noted that available data do not allow for firm conclusions. Executive Secretary Robert Floyd said in a statement that the seismic monitoring station in Kazakhstan captured “two very small seismic events” 12 seconds apart on June 22, 2020.
The organization’s network detects events equivalent to 551 tons of TNT or more, according to Floyd.
“These two events were far below that level,” Floyd said. “As a result, with this data alone, it is not possible to assess the cause of these events with confidence.”
China, a signatory to the 1996 Comprehensive Nuclear-Test-Ban Treaty but not a ratifier, rejected the initial U.S. accusation at an international conference this month. Beijing’s last acknowledged underground test occurred in 1996.
