On September 1996, the United Nations General Assembly adopted the Comprehensive Nuclear-Test-Ban Treaty (CTBT), prohibiting nuclear explosions worldwide, in all environments. The treaty calls for a global verification system, including a network of 321 monitoring stations distributed around the globe, a data communications network, an international data center (IDC), and on-site inspections to verify compliance. Seismic methods play the lead role in monitoring the CTBT. This volume concentrates on the measurement and use of surface waves in monitoring the CTBT. Surface waves have three...