Study Links North Korea’s 2017 Nuclear Test to More Than 1,300 Earthquakes
Researchers from South Korea and China found prolonged seismic activity around North Korea’s Punggye-ri test site, with more than 1,300 earthquakes recorded after the country’s largest nuclear test in 2017.
A major study has linked North Korea’s most powerful nuclear test to an extended surge in seismic activity around the Punggye-ri underground testing complex, raising new questions about the long-term geological effects of nuclear detonations.
A joint team from Pusan National University in South Korea and Chengdu University of Technology in China analyzed seismic-wave data covering 17 years from 2008. The findings were published in the peer-reviewed journal Science.
The researchers examined the area around Mount Mantap, where North Korea carried out six underground nuclear tests between 2006 and 2017. They found that seismic activity rose sharply after the country’s final test in 2017, which was also its largest. More than 1,300 earthquakes were subsequently detected, concentrated along a fault zone roughly 24 kilometers wide.
The pattern differed from the aftermath of earlier tests. About 60 earthquakes were detected following the first detonation in 2006, while tremors became more frequent around the time of the third test in 2013. Those earlier sequences were generally short-lived. By contrast, earthquakes after the 2017 explosion persisted and increased in both frequency and magnitude through 2025, the research team found.
The results suggest that the 2017 blast may have altered stresses in the surrounding rock and fault system, producing a sustained sequence rather than a brief cluster of aftershocks. The finding is significant because underground nuclear tests are designed to contain explosive energy, but that energy can still disturb nearby geological structures.
Kim Kwang-hee, a professor who led the South Korean side of the research, warned that the affected fault zone could produce an earthquake of up to magnitude 6.4 if it became active. That assessment describes a potential geological risk rather than a prediction that such an earthquake will occur.
Punggye-ri, in North Korea’s northeastern region, has long been the center of international monitoring because it hosted all six of the country’s declared nuclear tests. The new analysis adds a longer-term scientific dimension to those security concerns by showing that the site’s geological response may continue years after a detonation.
The study also demonstrates how seismic monitoring can reveal effects inside a highly restricted area. With direct access to the site unavailable, researchers rely on waves recorded by monitoring stations to estimate the location, strength and evolution of underground disturbances. Continued observation will be needed to determine whether the earthquake sequence is stabilizing or whether stresses remain active around Mount Mantap.