Introduction

Abstract

For over fourty years verification seismologists have been reporting on advances in event identification research at Professional Society Meetings and more recently at the Seismic Research Symposium held annually in the United States. This research has evolved over time as international treaties banning testing in certain environments or limiting the yield of nuclear weapons tests have been negotiated and signed. In recent years this research has targeted the challenges of verifying a Comprehensive Nuclear-Test-Ban Treaty (CTBT). In September 1996, the United Nations General Assembly adopted the 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, and on-site inspections, to verify compliance. The problem of identifying small-magnitude banned nuclear tests and discriminating between such tests and the background of earthquakes and mining-related seismic events, is a challenging research problem. The problem becomes particularly challenging as the magnitude of the event decreases, limiting the number of stations that see signal above the noise and increasing the number of background events that must be considered. This special volume is intended to report on seismic discrimination and identification research that has been ongoing since countries began to sign and ratify the CTBT in 1996.