North Korean Nuclear Test: Seismic Discrimination at Low Yield

North Korea carried out a widely reported nuclear explosion on 9 October 2006 at 0135 UTC at a location about 40 kilometers northwest of the city of Kilju (Figure 1). The location of the test determined from seismic signals recorded at 31 stations around the world was given as 41.294°N, 129.094°E in Quick Determination of Epicenters (QED) by the U.S. Geological Survey's National Earthquake Information Center (NEIC), very close to Mantap-san (Mount Mantap, 2205 meters, see Figure lc). Further, since the late 1990s, surveillance satellites have detected tunneling activity in this area suspected to be indicative of North Korea preparing to conduct nuclear tests at this site [Broad et al, 2005].