North Korea’s Nuclear Tests Linked to Increased Earthquakes
A recent study suggests that North Korea’s nuclear testing could be linked to an increase in seismic activity near its primary test site, particularly after the last tests in 2017.
The research highlights data collected from seismic waves, supported by institutions such as the National Science Foundation of China and the National Research Foundation of Korea. Between 2008 and 2025, scientists recorded 1,399 earthquakes around Mount Mantap, the site of six underground nuclear tests conducted from 2006 to 2017.
It’s well-documented that nuclear tests, like those in Nevada during the Cold War, can trigger small, transient earthquakes. Yet, the situation in North Korea is somewhat unusual, as earthquakes normally don’t see a rise for years following such blasts.
“I think the broader lesson is that short-lived disturbances can have consequences that persist for years or even decades,” remarked Sunyoung Park, an assistant professor at the University of Chicago’s geophysical sciences department, who wasn’t part of the research. “The Earth’s crust has a long memory.”
The earliest quake noted in the study was recorded in 2013, following North Korea’s third nuclear test. While seismic activity was relatively low after that, it spiked in 2017 after the sixth, and largest, test, marking a significant increase.
“We were basically very shocked,” stated Kwang-Hee Kim, a professor at Pusan National University and a lead author of the study. “The seismic trend was so clear and linear.”
Sunyoung Park added, “In most previous cases, earthquakes triggered by underground nuclear tests declined relatively quickly after the initial disturbance. Here, the opposite seems to be happening: seismicity has persisted and even increased over time.”
The research team speculates that the heightened earthquake frequency and intensity indicate that the Earth’s crust may not have returned to its pre-test state after 2017’s nuclear detonation.
Kwang-Hee Kim proposed that the activation of at least two existing faults could have contributed to this increased seismicity, influenced by Mount Mantap’s uneven terrain. The explosion may have reawakened old fractures in the mountain while also creating new ones, which could, in turn, build pressure from accumulating water, ultimately leading to earthquakes.
Interestingly, the region around this mountain had been notably quiet for about 2,000 years prior to the onset of nuclear testing.
“We have more than 2,000 years of historical record in China and Korea. We have one event about 100 kilometers away,” Kim mentioned. “I cannot say there’s no earthquakes, but the seismic activity here is very low.”
In a significant development, North Korea dismantled the Punggye-ri nuclear test site in May 2018. This was accomplished by detonating underground tunnels and demolishing surrounding buildings, a move that was publicly showcased to international journalists. This closure followed an order from Supreme Leader Kim Jong Un, coinciding with a major summit with then-President Donald Trump.
