Archive · 19 Sep 2026
Study Links North Korea's Nuclear Tests to 1,399 Earthquakes
Scientists found many small earthquakes near North Korea’s nuclear test site.
They studied recordings made from 2008 through 2025.
The site is near Mount Mantap, where six underground nuclear tests took place.
The area had very little earthquake activity before the tests.
Earthquake activity increased greatly after the biggest test in 2017.
That explosion caused a magnitude 6.3 earthquake and may have damaged a tunnel.
Researchers think the blast reopened old cracks and made new cracks in the rock.
Water may have entered those cracks and helped the rocks slide.
That movement could have caused many small earthquakes over several years.
Researchers detected 1,399 earthquakes near Mount Mantap in seismic data from 2008 to 2025.
North Korea conducted six underground nuclear tests at the site between 2006 and 2017.
Earthquake activity increased sharply after the 2017 test, which produced a magnitude 6.3 earthquake.
Most later earthquakes measured magnitudes between 2 and 3 and occurred at shallow depths.
Researchers suspect the explosions reactivated faults and created water-filled cracks that allowed rocks to shift.
- Who
- Researchers from China and South Korea, including a scientist at Pusan National University, studied the seismic activity.
- What
- A study detected 1,399 earthquakes near Mount Mantap and found that activity increased after North Korea’s nuclear tests, particularly after 2017.
- When
- The seismic data covered 2008 to 2025; activity rose markedly after the sixth test in 2017.
- Where
- Near Mount Mantap, North Korea’s main underground nuclear test site.
- Why
- Researchers suspect the explosions reactivated existing faults and created water-filled cracks that increased pressure and enabled rocks to move.
- Earthquakes detected
- 1,399 near Mount Mantap between 2008 and 2025
- Nuclear tests
- Six underground tests were conducted between 2006 and 2017
- Largest test
- The 2017 test produced a magnitude 6.3 earthquake
- Typical earthquake magnitude
- Most later earthquakes measured between magnitudes 2 and 3
- Detection method
- Researchers used waveforms from known earthquakes to identify weaker events in background noise
- Suspected mechanism
- Reactivated faults and water-filled cracks may have allowed rocks to slide
- Reported structural effects
- The 2017 explosion may have caused a tunnel collapse and changed the mountaintop’s shape by about 3 meters
