The Japanese government adopted to implement a special radiological survey (collection of radioactive dust and noble gases) after North Korea detonated a hydrogen bomb sparking a powerful 6.3 magnitude earthquake.

The test was estimated to have a yield of 100 kilotons, meaning a blast that was four to five times more powerful than the explosion in Nagasaki, Japan, in 1945, a South Korean defense official told the country’s Yonhap News Agency.

“Based on an instruction from the Minister of Defense and an agreement reached at the Liaison Meeting for Radiological Countermeasures, the Ministry of Defense will implement a special radiological survey (collection of radioactive dust and noble gases) from September 3 until a date to be indicated separately” said on report of Japanese Ministry of Defense.

The Japanese military has radiological detection equipment in some of its jets as well. The Japanese Air Force has T-4 intermediate jet trainer aircraft that will be measuring the air samples near the Korean Peninsula to confirm the presence of radioactive particles in the atmosphere and confirm the nuclear test.