NORTH KOREA (OBSERVATORY) – North Korea’s nuclear testing site may be unusable due to a partial collapse of the mountain it was in during the last test in September, Chinese seismologists said in a study.
North Korean leader Kim Jong-un declared a moratorium on nuclear tests and intercontinental ballistic missiles on Saturday, as well as the closure of the Bungi-ri site, where North Korea conducted its six tests between 2006 and 2017.
The announcement came days before Friday’s summit between Kim Jong-un and South Korean President Moon Jay-en. It is expected to be followed a few weeks later by a historic meeting between Kim and US President Donald Trump.
North Korea’s sixth and last nuclear test, the strongest to date, caused a magnitude 6.3 earthquake on September 3, and people felt it even in China. Pyongyang said it had tested a hydrogen bomb.
The experience has led to landslides and aftershocks that have led some experts to believe that Mount Mantab, under which experiments were conducted, could be hit by the intensity of the “mountain syndrome”.
This syndrome applies to a site whose geological structure has been weakened by frequent underground nuclear explosions.
Two studies involving Chinese experts revealed that a tremor of magnitude 4.1 occurred eight minutes after the experiment led to the collapse of rocks inside the mountain.
“It is necessary to continue to monitor the possible emissions of radioactive materials caused by the collapse,” the University of Science and Technology said in a study published on its Web site.
The study will be published in a publication by the American Geophysics Association.
In a summary in English, the authors of the study considered on another page of the university site that “the collapse will make underground infrastructure in Mount Mantab, unusable for nuclear testing.”
But the comment did not appear in the study summary in Chinese, and it was not known whether it would appear in the US Geophysical Union.