An “artificially caused” 5.3 magnitude tremor detected in North Korea on Friday morning (local time) appears to be the result of a nuclear test conducted by Pyongyang. It has not yet been confirmed that a nuclear weapons test caused the seismic activity, but the tremor was near the site of four previous tests by the North Koreans. “The U.S. Geological Survey, which monitors global seismic activity, said Friday morning’s tremor had been detected in that area and was caused by ‘an explosion,’” the BBC reports.
The China Earthquake Networks Center also suspects the tremor to be an explosion, Reuters reports, and South Korea called for an emergency National Security Council meeting. Despite international pressure on Kim Jong-un to halt his country’s nuclear weapons program, including a decade of U.N. Security Council sanctions that were ratched up earlier this year, there were signs North Korea was readying itself for another test, its second this year. “Two months ago, U.S.-based 38 North, a North Korea monitoring project, said satellite images showed a high level of activity at North Korea’s nuclear test site, called Punggye-ri,” Reuters reports.
“The US Air Force is expected to start flying the WC-135 Constant Phoenix Aircraft in the coming hours to take air samples and see if it can determine a nuclear event occurred,” according to CNN.