Two weeks after the blast , a monitoring station at Yellowknife in northern Canada detected traces of the radioactive noble gas xenon in the air . The presence of xenon provides evidence that a nuclear explosion has taken place . This detection confirmed that the 2006 North Korean nuclear test was a nuclear explosion . Analysts at the CTBTO then used special calculations to backtrack the detected xenon to determine its source . The calculation indicated that the detected noble gas originated from North Korea
2006 North Korean nuclear test
2006 North Korean nuclear test
Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization