MONITORING FOR NUCLEAR EXPLOSIONS.

The article explains that systems are in place that can detect a nuclear weapon test of a kiloton or greater anywhere on the Earth, making it impossible for any nation to test nuclear devices without the world's knowledge. Scientists have accomplished this through the use of seismic technologies. The author also mentions U.S. President Barack Obama's intentions to ratify the Comprehensive Nuclear-Test-Ban Treaty. INSETS: How to Tell a Blast from a Crash;How Monitoring for the Treaty Covers Earth;WHAT GOOD IS A TEST?;Fifty Years of Nuclear Testing and Monitoring