Both South Korean and Japansese authorities and the US Geological Survey have measured
an earthquake in Kilju county, North Korea, where the Punggye-ri test site is located,
at a depth of approximately 1km.
Reports are the quake measured between magnitude 4.9 and 5.2 and there is
speculation as to whether the North Koreans have detonated another nuclear device.
Story here -
http://www.smh.com.au/world/fake-qua...212-2eagi.html