Satellite imagery of North Korea's main nuclear test site indicates that Pyongyang could be in the final stages of preparations for a sixth nuclear test in defiance of United Nations sanctions. The latest unclassified imagery suggests communications cables used to initiate a test and collect data may have been laid already. North Korea's previous five nuclear tests were all conducted at its Punggye-ri site in the depths of Mount Mantap, a nondescript granite peak in the remote and heavily forested Hamgyong mountain range. The existence of Punggye-ri is hardly a secret. It's a favorite target of spy satellites -- military and commercial -- and North Korea even released a propaganda film depicting it in 2010. The Associated Press report that the film shows it is a tunnel in the shape of a fish-hook, which is what experts might expect. Pakistan used a similar design. Concern that another test is looming has been heightened recently by images from satellites and analysis by experts Joseph Bermudez and Jack Liu on the website 38 North. The imagery from March 25 shows the continued presence of three to four vehicles or equipment trailers at the entrance to the tunnel, with communications cables likely used to initiate the test, collect data from the explosion and process the data.
