Like an earthquake, the force of an underground nuclear explosion creates seismic waves that travel through the Earth. A satisfactory seismic network to monitor such tests must be able to both detect and identify seismic signals in the presence of "noise," for example, from natural earthquakes. In the case of monitoring a treaty that limits testing below a certain size explosion, the seismic network must also be able to estimate the size with acceptable accuracy. All of this must be done with an assured capability to defeat adequately any credible attempt to evade or spoof the monitoring network. This report addresses the issues of detection, identification, yield estimation, and evasion to arrive at answers to the two critical questions: (1) Down to what size explosion can underground testing be seismically monitored with high confidence? (2)How accurately can the yields of underground explosions be measured? In doing so, we assessed the contribution that could be made if seismic stations were located in the country whose tests are to be monitored, and other cooperative provisions that a treaty might include.
Woodrow Wilson School of Public and International Affairs, Princeton University, http://www.wws.princeton.edu/~ota