North Korea nuclear test site shows rising seismic activity

Researchers have identified a significant and prolonged increase in seismic activity at North Korea’s Punggye-ri nuclear test site, located beneath Mount Mantap. According to a study published in the journal Science, the area has experienced 1,399 earthquakes between 2008 and 2025, with the frequency and magnitude of these events increasing steadily following the country’s final and most powerful nuclear test in September 2017.

Unlike typical post-explosion patterns where seismic disturbances are short-lived, the activity at Mount Mantap has persisted for years. The study, involving researchers from China and South Korea, suggests that the 2017 detonation—which had an estimated yield of 100 to 250 kilotons—did not allow the Earth’s crust to return to equilibrium. Instead, the explosion appears to have reactivated previously dormant fault lines, causing seismic activity to expand gradually over time.

Lead authors and contributing scientists noted that while nuclear tests traditionally cause localized, temporary tremors, the progressive increase in the earthquake rate and moment release rate indicates a more permanent shift in the local crustal stability.