Discrimination between earthquakes and chemical explosions in Eastern Russia using amplitude ratios obtained from analog records

Abstract

Discrimination between earthquakes and chemical explosions is a significant problem facing many regional seismic networks around the world. Both earthquakes and chemical explosions are sources of elastic waves; therefore, both are recorded by seismic networks. Interest in the field of explosion discrimination grew enormously as a result of the negotiations for and of support of the Partial Test Ban Treaty (PTBT) in 1963, the Nonproliferation Treaty (NPT) in 1968, and the current Comprehensive Test Ban Treaty (CTBT) negotiated in 1993 and adopted in 1996. The possibility of negotiating and verifying the CTBT depends in part on the ability of seismic networks to seismically detect and identify underground nuclear tests and other seismic sources, such as earthquakes. Currently, interest in event discrimination is also associated with the identification and search for active seismic sources in areas where both earthquakes and explosions are recorded by seismic networks. If explosions are not removed from the seismic catalogs of these areas, there is an “explosion contamination” that can result in a misinterpretation of the regional tectonics, and an erroneous assessment of the natural seismic hazard. This “explosion contamination” is the particular aspect that motivated the present study.