[278-3] Nuclear Comprehensive Test Ban Treaty Monitoring Network, 2013
Each of the 338 (225 have been certified) sites used to monitor nuclear activity on earth are shown. Large and small radiating dots represent the Primary and Auxillary Seismic monitoring sites, which measure waves traveling through the earth and can identify location, strength and nature of a seismic event. Squares are locations of the Infrasound monitoring sites, which measure micropressure changes in the atmosphere, generated by infrasonic waves. Triangles show the Hydroacoustic sites which monitor the globe's oceans using underwater hydrophone sensors. Lastly, small circles represent the Radionuclide sites which take air samples to measure its radioactive content; specific radionuclides can provide evidence of a nuclear explosion.
[278-2] Nuclear Comprehensive Test Ban Treaty Monitoring Network, 2011
Locations of the seismic, hydroacoustic, infrasound, and radionuclide sensing facilities of the Comprehensive Nuclear-Test-Ban Treaty International Monitoring System, as well as The International Data Centre of the CTBTO, located in Vienna. As of 2005 the treaty is not yet in effect, pending ratification of all 44 states listed in Annex 2 of the treaty.