North Korea’s Underground Nuclear Tests Are Reactivating Dormant Earthquake Fault Lines

A study in Science showed that after six North Korean underground nuclear tests at the Punggye-ri test site at Mount Mantap, seismic activity did not subside but increased. From September 2017 to May 2025, 1,399 local earthquakes were recorded — a record for the region since 1904.

• The September 3, 2017 test was estimated at 100–250 kilotons — 10 times the Hiroshima bomb
• From 2008 to 2025, 1,399 local earthquakes were recorded at Mantap
• Activity began on September 23, 2017 and continued until May 2025
• Data was collected from seismic stations in China and South Korea 80–200 km from the test site