SEISMOLOGY:
Did Test Ban Watchdog Fail to Bark?
Eliot Marshall
Opponents of the Comprehensive Test Ban Treaty (CTBT) are finding fault with the global seismic detection system that monitors compliance, because it missed India's announced second round of nuclear blasts in May. They are now trying to cut its budget. But a strong consensus has emerged among U.S. seismologists that the system worked well and should easily have detected a blast even smaller than India's claim of the equivalent of 800 tons of TNT; they believe that an 800-ton blast would have been visible all over the world. This has led some experts to suggest that the announced tests on 13 May may have been at most small subcritical blasts fueled by chemical explosives--"hydrodynamic" experiments of the type detonated occasionally by U.S. and Russian weapons engineers and not considered a bomb test under the CTBT.
