My friend Dave wrote me tonight: “That North Korean nuclear test claim? I checked the USGS website. Within an hour of the claim, they had posted data consistent with a nuclear test – 4.2 magnitude (too big to fake easily), depth 0 km, location pinned to a hillside in NE North Korea that has surprisingly good aerial coverage on the crosslinked Google Earth map – given that it’s a site long noted as a possible test facility. There is a road leading straight up to the base of the mountain, then disappearing.”
That’s pretty convincing!
Edit 2014: corrected links to usgs.gov and maps.