On September 10, 1996, the United Nations General Assembly voted 158-3 to approve a treaty prohibiting all nuclear tests. The Comprehensive Test Ban Treaty has been signed by 130 nations - including the United States. President Clinton signed the agreement on September 24, 1996.
Seismology is one of several fields which plays a role in monitoring the Comprehensive Test Ban Treaty. Underground nuclear explosions produce seismic waves with unique characteristics which allow the discrimination between explosions and earthquakes.