Comprehensive Nuclear-Test-Ban Treaty
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An International Monitoring System (IMS) is being constructed to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty
A Comprehensive Nuclear-Test-Ban Treaty (CTBT) to ban all nuclear explosion tests was opened for signature in New York on 24 September 1996. Australia signed the Treaty on the same day and ratified it on 9 July 1998. As of November 2010, 182 countries have signed and 153 have ratified. To see the latest country to sign or ratify and to find more information on the CTBT Organisation visit their website at https://www.ctbto.org.
An International Monitoring System (IMS) is being constructed to monitor compliance with the Treaty. By analysing, integrating and comparing data from the IMS, the time, location and nature of a possible nuclear event can be determined. The network consists of 321 monitoring facilities and 16 radionuclide laboratories that monitor the earth for evidence of nuclear explosions in all environments. These monitoring facilities use a variety of methods to detect evidence of nuclear testing. Seismic, hydroacoustic and infrasound stations are employed to monitor the underground, underwater and atmosphere environments, respectively. The fourth technology detects radiation from atmospheric sampling.
Seismic (50 Primary & 120 Auxiliary)
Seismic monitors detect vibrations in the earth’s crust. The principal use of the seismic data in the verification system is to locate seismic events and to distinguish between an underground nuclear explosion and the numerous earthquakes that occur around the globe.
Hydroacoustic (11 stations)
Hydroacoustic monitoring detects acoustic waves produced by natural and artificial phenomena in the oceans. The data from the hydroacoustic stations are used in the verification system to distinguish between underwater explosions and other phenomena, such as sub-sea volcanoes and earthquakes, which also propagate acoustic energy into the oceans.
Infrasound (60 stations)
The infrasound network uses microbarometers (acoustic pressure sensors) to detect very low-frequency sound waves in the atmosphere produced by natural and artificial events. The data collected is used to distinguish between atmospheric explosions and natural phenomena such as meteorites, explosive volcanoes, meteorological events and artificial phenomena such as re-entering space debris, rocket launches and supersonic aircraft.
Radionuclide (80 stations)
The 80 radionuclide stations can detect radioactive debris from atmospheric explosions or vented by underground or underwater nuclear explosions. The presence of specific radionuclides provides unambiguous evidence of a nuclear explosion. Forty of these stations will be capable of measuring for the presence of the relevant noble gases. See below for more on how these stations work.
Radionuclide laboratories (16 stations)
The 16 Radionuclide Laboratories are used to verify samples that are suspected of containing radionuclide materials that may have been produced by a nuclear explosion.
ARPANSA is responsible for carrying out Australia's radionuclide monitoring obligations to the Comprehensive Nuclear-Test-Ban Treaty, and also responsible for the installation, implementation and operation of seven stations within Australia and its Territories.
Australia hosts all four technologies totalling 21 facilities within Australia and its territories.
|Location||State or Territory||Type||Treaty Code||Coordinates|
|Charters Towers||Queensland||Auxiliary Seismic Station||AS004||-20.1||146.3|
|Fitzroy Crossing||Western Australia||Auxiliary Seismic Station||AS005||-18.1||125.6|
|Narrogin||Western Australia||Auxiliary Seismic Station||AS006||-32.9||117.2|
|Cape Leeuwin||Western Australia||Hydroacoustic Station||HA01||-34.4||115.1|
|Davis Base||Antarctica||Infrasound Station||IS03||-68.4||77.6|
|Narrogin||Western Australia||Infrasound Station||IS04||-32.9||117.2|
|Cocos Islands||Western Australia||Infrasound Station||IS06||-12.3||97|
|Warramunga||Northern Territory||Infrasound Station||IS07||-19.9||134.3|
|Warramunga||Northern Territory||Primary Seismic Station||PS02||-19.9||134.3|
|Alice Springs||Northern Territory||Primary Seismic Station||PS03||-23.7||133.9|
|Stephens Creek||South Australia||Primary Seismic Station||PS04||-31.9||141.6|
|Mawson||Antarctica||Primary Seismic Station||PS05||-67.6||62.9|
|ARPANSA, Melbourne||Victoria||Radionuclide Laboratory||RL02||-37.5||144.6|
|Townsville, QLD||Queensland||Radionuclide Station||RN06||-19.2||146.8|
|Macquarie Island||Tasmania||Radionuclide Station||RN07||-54||159|
|Cocos Islands||Western Australia||Radionuclide Station||RN08||-12||97|
|Darwin||Northern Territory||Radionuclide Station||RN09||-12.4||130.7|
|Perth||Western Australia||Radionuclide Station||RN10||-31.9||116|
|The radionuclide monitoring process involves collecting particulate matter from the air onto a piece of filter material on a high volume air sampler for about 24 hours.|
|After this time the filter is taken from the air sampler, compressed into a disk.|
|The disk is then placed in a chamber to allow natural radionuclides to decay for about 24 hours.|
|Finally, the filter sample is placed on a gamma detector for about 24 hours to be analysed.|
|A computer monitors the workflow and collects data.|
|The data relating to the sampling conditions and radionuclides measured is then forwarded by satellite to the International Data Centre in Vienna where it is compiled and released to countries participating in the Treaty.|