New flash animations explain how monitoring technologies work

Continuous progress is being made in establishing a global alarm system to monitor the Earth for signs of a nuclear explosion.  The system consists of the International Monitoring System (IMS) with a network of 337 monitoring stations, the International Data Centre (IDC) for the analysis of monitoring data, a Global Communications Infrastructure (GCI) and on-site inspections.  The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is building this verification regime to prevent any nuclear explosion conducted underground, underwater or in the atmosphere from going undetected.

This animation of the CTBT global alarm system was launched along with the new CTBTO web site in June 2008. Click the image to start the animation.

How can nuclear explosions be detected?

So how exactly are nuclear explosions detected?  The verification regime’s IMS uses four distinct technologies to monitor the entire globe for nuclear explosions: seismic, hydroacoustic, infrasound and radionuclide technologies.  Four new flash animations are now available on the CTBTO website explaining how these technologies detect the tell-tale signs of a nuclear explosion.  

Seismic monitoring

Seismic technology is used to detect underground nuclear explosions.  Seismic sensors at 170 seismic stations around the world measure seismic waves generated by events such as earthquakes or explosions.

To learn more about seismic monitoring click here.

Hydroacoustic monitoring

Hydroacoustic technology is employed to monitor the Earth’s oceans for signs of nuclear explosions.  Only eleven stations are required to monitor the major oceans due to the efficient propagation of acoustic waves in the water.  Underwater sensors at most stations detect sound waves generated by underwater events such as explosions, volcanic eruptions or earthquakes.

To learn more about hydroacoustic monitoring click here.

Infrasound monitoring

Infrasound technology helps to detect nuclear explosions in the atmosphere or in the shallow underground.  Infrasound sensors are installed at 60 stations worldwide to listen to infrasound waves created by events such as storms, volcanic eruptions or explosions. 

To learn more about infrasound monitoring click here.

Radionuclide monitoring

Radionuclide technology is used to detect specific radioactive particles and noble gases in the atmosphere that are generated by a nuclear explosion.  When detected at any of the 80 radionuclide stations around the world, these radionuclide particles and noble gases provide unambiguous evidence that a nuclear explosion was conducted. 

To learn more about radionuclide monitoring click here.