We get it, North Korea. You’re weird, unpredictable, and now (questionably) well-armed. Want to stop lobbing missiles all over the place and setting off nuclear bombs underground? No? Then what do you want? To bring about a premature end to our sad little world? Because that’s how you bring about a premature end to our sad little world. Especially when your nuclear tests cause unexplained seismic activity felt around the world.
Scientists with the US Geological Survey (USGS) and the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) first detected the massive seismic activity triggered by North Korea’s latest underground nuclear test on September 3rd, measuring between 6.1 and 6.3 on the Richter Scale. That makes it the largest seismic activity caused by a nuclear test ever measured. Good job, North Korea.
What followed, however, is a complete mystery. Almost eight minutes after the nuclear test, those same seismic monitoring stations detected a magnitude-4.1 seismic event. Just what that event might have been is unknown at this point, and scientists are at a complete loss to explain it. The most current thinking is that the explosion caused some sort of structural collapse of the mountain under which the nuclear device was tested. Satellite photos taken before and after the event show evidence of landslides. However, the particular seismic waves caused by this event indicate some sort of horizontal movement of the rock bed, something a mountain collapse wouldn’t normally trigger.
Columbia University seismologist Won-Young Kim believes that the mysterious seismic event could be a secondary earthquake caused by rock beds exploding deep within the Earth in the aftermath of the nuclear test. One of Kim’s colleagues, Göran Ekström, is at a loss, saying only that the event “is an interesting mystery at this point.” Could this be some type of man-made earthquake? Or could North Korea have actually tested some unknown type of weapon or even a hydrogen bomb, causing unforeseen underground mayhem? Given how secretive the Hermit Kingdom is, we’ll likely never know.