Tracking the North Korean nuclear explosion of 2006, using seismic data from Japan and satellite data from Taiwan

The location of the 2006 nuclear explosion in North Korea has been accurately imaged by back-projected regional Pn waves recorded by the Japanese Hi-net array. Based on the determined location, the nuclear explosion site can be identified from geo-referenced FORMOSAT-2 satellite images. The seismically determined epicenter is about 2.5 km northeast of the original estimate of its absolute location. Results indicate that a remote suspect event had been unambiguously detected and accurately located by a dense array within a regional distance. Employing ground truth correction, the satellite images can be referenced for shifting the array-determined epicenter to its absolute position. After correction, this event can be treated as a reference event for accurately locating future nuclear explosions. Our study utilizes public information from a dense seismic network and further demonstrates that commercial observation satellites can accurately monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty, as well as earthquake and tsunami hazards almost in real time.