Удк 550.34:621.039.9 Analysis of Digital Seismograms from Nuclear Explosions across Forty Years

It is remarkable that the most recent nuclear test explosion, by North Korea (2006 October 9), although quite small, was well-detected teleseismically. We describe how this event was promptly identified as an explosion and not an earthquake, on the basis of regionally recorded signals, in a region that apparently would have permitted such identification even if the test had been much smaller. The work of identifying underground nuclear explosions in a particular region on the basis of their seismic signals is greatly assisted by the availability of high-quality signals from both explosion (chemical or nuclear) examples, and earthquake examples, previously recorded in that same region. The Borovoye Geophysical Observatory is very important for its digital seismogram archive of nuclear explosions going back to 1966, recorded from underground nuclear tests at teleseismic and regional distances, from test sites operated by the recognized nuclear weapons states. We briefly describe a current effort to improve the quality and usability of this archive.