Monitoring sites in countries around North Korea reported seismic activity in that country Saturday, but differed on whether the quake was likely to be natural or man-made, such as a nuclear test.
South Korea’s weather agency reports a magnitude 3.0 earthquake in an area of North Korea where the country recently conducted a nuclear test, but assessed the seismic activity as natural.
"The quake is presumed to have occurred naturally," an agency official said, according to South Korea's Yonhap news agency. "A sound wave, which is usually generated in the event of an artificial earthquake, was not detected."
The Korea Meteorological Administration said the activity occurred in Kilju in North Hamgyeong Province.
https://www.usatoday.com/story/news/world/2017/09/23/north-korea-earthquake-nuclear-test-site/696080001/