Research by Chinese geologists suggests that the mountain above North Korea's main nuclear test site has likely collapsed, rendering it unsafe for further testing and requiring that it be monitored for any leaking radiation. In a Sept. 3, 2017, image distributed by the North Korean government, North Korea's leader Kim Jong Un holds a meeting of the ruling party's presidium. The findings may shed new light on North Korean President Kim Jong Un's announcement that his country was ceasing its testing program. North Korea's nuclear tests are of special concern to Beijing, since the test site near the town of Kilju is less than 100 kilometres (60 miles) from the border with China. The region isn't one where earthquakes naturally occur and no quakes were detected after the five smaller nuclear tests North Korea has conducted since 2006.

Source: CBC News April 26, 2018 14:37 UTC