"We use several methods to tell whether earthquakes are natural or manmade," said the official, who asked for anonymity. "A key method is to look at the seismic waves or seismic acoustic waves and the latter can be detected in the case of a manmade earthquake. The earthquake was detected in Kilju county in North Hamgyong Province, where North Korea's known Punggyeri nuclear site is located, the official said. All of North Korea's previous six nuclear tests registered as earthquakes of magnitude 4.3 or above. Tensions have continued to rise around the Korean peninsula since Pyongyang carried out its sixth nuclear test, prompting a new round of UN sanctions.

Source: bd News24 September 23, 2017 10:41 UTC