North Korea nuclear tests trigger sustained seismic activity

Research analyzing seismic data from 2008 to 2025 reveals that North Korea’s underground nuclear tests have triggered a continuous and accelerating increase in earthquake activity near the Punggye-ri test site at Mount Mantap. While seismic disturbances from nuclear tests typically subside within weeks or months, scientists have detected approximately 1,399 small earthquakes in the region, with activity increasing in both frequency and magnitude since the final major test in 2017.

Studies conducted by teams from the University of Chicago and Chengdu University of Technology indicate that the explosions have reactivated existing fault lines and potentially exposed a previously unmapped hidden fault. The research suggests a “delayed effect” caused by the redistribution of stress within the crust and the potential infiltration of groundwater into new fractures, which increases pore pressure and facilitates fault movement years after the initial blasts.

Geological modeling shows that the steep, heavy slopes of Mount Mantap exerted significant natural vertical pressure on the underlying rock. The six nuclear tests conducted between 2006 and 2017 weakened the crustal integrity, pushing the rock into a critical stress state. Although there is no direct evidence of further nuclear testing since 2017, reports from the IAEA and US intelligence suggest repairs and restoration activities have occurred at the test site.