The National Earthquake Database (NEDB) comprises a number of separate databases that together act as the national repository for all raw seismograph data, measurements, and derived parameters arising from the Canadian National Seismograph Network (CNSN), the Yellowknife Seismological Array (YKA), previous regional telemetered networks in eastern and western Canada (ECTN, WCTN), local telemetered networks (CLTN, SLTN), the Regional Analogue Network, and the former Standard Seismograph Network (CSN). It supports the efforts of Earthquakes Canada in Canadian seismicity monitoring, global seismic monitoring, verification of the Comprehensive nuclear Test Ban Treaty, and international data exchange. It also supports the Nuclear Explosion Monitoring project.