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From ending nuclear testing to detecting tsunamis and missing aircraft: the wider applications of the Nuclear-Test-Ban Treaty

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) prohibits all nuclear explosions anywhere as an effective measure of nuclear disarmament and non-proliferation but is yet to come into force. On 11 April SIPRI, in cooperation with the Swedish Ministry for Foreign Affairs (MFA) and the Swedish Institute of International Affairs (UI), held an event to discuss the CTBT and its wider applications. 

The CTBT has been signed by 183 states and ratified by 162, but eight nuclear-capable states—China, the Democratic People’s Republic of Korea (DPRK, North Korea), Egypt, India, Iran, Israel, Pakistan and the United States—still have to join in order for the CTBT to enter into force.

On 26 September 2013, in order to ensure an innovative and focused approach to encouraging the remaining eight states to join the CTBT, a Group of Eminent Persons (GEM) was launched. The Foreign Ministers of Hungary, Indonesia and Italy are among the 20 members of the GEM, which held its first substantive meeting in Stockholm on 10 April 2014 at the invitation of Sweden’s Foreign Minister, Carl Bildt.

The panel discussion

On 11 April, as a follow-up, SIPRI, the Swedish MFA and UI hosted a panel discussion on the CTBT (PDF). Speakers included Hans Blix, who served as Executive Chairman of the UN Monitoring, Verification and Inspection Commission for Iraq, Director General of the International Atomic Energy Agency (IAEA), and Minister for Foreign Affairs of Sweden; Kevin Rudd, former Australian Prime Minister and Foreign Minister; and Lassina Zerbo, Executive Secretary of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO).

Hans Blix discussed the long effort to abolish nuclear testing and the continuing efforts to achieve a world without nuclear weapons. Kevin Rudd noted that SIPRI is ranked among the leading research institutes in the world, and discussed the prospects of the ratification of the CTBT by China, highlighting the dynamics of the China–USA relationship in this regard. Finally, Lassina Zerbo highlighted the verification technologies of the CTBTO which will ensure that no nuclear test goes undetected.

The CTBT verification system

For the purposes of the verification of the CTBT, a global network of 321 monitoring stations and 16 laboratories is being set up. This network is designed to detect nuclear tests, providing a powerful system that can also give early warning of tsunamis, nuclear accidents and earthquakes.

The verification system is designed to detect any nuclear explosion conducted on the surface of the Earth—underground, underwater or in the atmosphere. The International Monitoring System (IMS) of the CTBT relies on four complementary verification technologies, utilizing the most modern science available. Seismic, hydroacoustic and infrasound stations monitor the depths of the Earth, the world’s oceans and the atmosphere, respectively, while radionuclide stations detect radioactive debris from atmospheric explosions or vented by underground or underwater nuclear explosions.

The IMS monitoring stations and laboratories will operate in 89 countries around the world. Setting up these facilities entails engineering and construction challenges unprecedented in the history of arms control, as many stations are located in remote and inaccessible regions. The science and technology applications of the IMS have a number of civilian uses.

Determining the time of plane crashes

The CTBTO’s IMS network was recently employed in the search for missing airplane MH370. If a large aircraft crashes into the ground, it creates seismic signals equivalent to small magnitude earthquakes that can be picked up by IMS seismic stations. The exact time of the impact of the Pan Am Boeing 747 near the Scottish town of Lockerbie and the crash of a Swiss Air MD11 near Halifax in Canada (both in 1998) could only be verified accurately by using seismic data.

Similarly, the CTBTO was asked to review its data to see if the missing Malaysian Boeing 787, flight MH370, had crashed into the ground and to determine the crash location. In addition, if a plane explodes in mid-air—as did TWA Boeing 747 on 17 July 1996—the sound of the explosion can be picked up by infrasound sensors.

Detecting volcanic eruptions, earthquakes and tsunamis

The technology employed in the IMS network can also pick up the low-frequency sounds of breaking icebergs and volcanic eruptions. In 2010, for example, the eruption of a volcano in Iceland closed large parts of European airspace for days due to the ash spewed into the atmosphere, disrupting thousands of flights. The meteor which disintegrated over Chelyabinsk on 15 February 2013 created a sound wave that travelled twice around the world. The infrasound technology provides scientific data on the disintegration in the atmosphere of meteorites for analysis by the scientific community.

Large magnitude earthquakes can result is tsunamis or huge waves on the ocean. In December 2004 a large earthquake off the coast of Sumatra was followed by a tsunami that killed thousands of people. In March 2011 the Great East Earthquake off Fukushima triggered a huge tsunami that killed thousands and resulted in a nuclear accident following loss of electricity generators that pumped cooling water in four nuclear power reactors.

After the 2004 earthquake and tsunami, the CTBTO was mandated to provide data from its seismic and hydroacoustic stations to tsunami warning centres to enhance the ability of potentially tsunami-generating earthquakes. In 2011 this information was also provided to the IAEA nuclear emergency centre to warn nuclear power plant operators against tsunami-generating earthquakes.

Noble gases

Radionuclides such as cesium, iodine, and xenon are released following underground nuclear tests and from nuclear facilities. The noble gases released as a result of the Fukushima nuclear accident corresponded to an atmospheric nuclear explosion of one megaton or 1000 kilotons—in comparison, the atomic bomb dropped on Nagasaki was about 21 kilotons. The IMS radionuclide monitoring system can enable global tracking of radionuclides, thus informing publics about the transport in the air of radionuclides.

The CTBTO’s IMS provided tracking of the radioactive emissions from the damaged Fukushima nuclear power plants following the massive earthquake on 11 March 2011. The CTBTO, using more than 35 radionuclide monitoring stations, provided information on the spread of radioactive particles and noble gases from the Fukushima accident, and showed that minute traces of radioactive emissions from Fukushima had spread across the entire northern hemisphere as well as across the southern hemisphere of the Asia-Pacific region.

Ending nuclear testing

While the civilian and disaster-related applications of the CTBTO’s monitoring systems are extremely useful, it is important to remember that the purpose of the CTBT is the abolition of all nuclear tests.

Nuclear testing has a long history, beginning in 1945. Nuclear explosions have been detonated in all environments: above ground, underground, underwater and in space. Bombs have been detonated on top of towers, on board barges, suspended from balloons, on the earth's surface, underwater to depths of 600 metres, underground to depths of more than 2400 metres and in horizontal tunnels. Test bombs have been dropped by aircraft and fired by rockets up to 250 kilometres into the atmosphere.

Atmospheric testing was banned by the 1963 Partial Test Ban Treaty. Negotiations had largely responded to the international community’s grave concern over the radioactive fallout resulting from atmospheric tests. The USA, the Soviet Union, the United Kingdom, Pakistan and India became parties to the treaty; France and China did not. France conducted its last atmospheric test in 1974, and China in 1980.

The CTBT is an essential step towards achieving a world free of nuclear weapons. By ending nuclear testing it prevents the development of new nuclear weapons and the emergence of additional states with such weapons. It should be the goal of world leaders to ensure that the CTBT is in force no later than 24 September 2016—its 20th anniversary.



Tariq Rauf is the Director of the Disarmament, Arms Control and Non-Proliferation Programme.