Glossary

T-phase

A type of sound wave in the water that is created when a seismic wave hits the water.  T-phases are usually generated by earthquakes under the ocean floor. Seismic waves propagate from the epicentre of the earthquake and turn into hydroacoustic waves when they enter water.

T-Phase station

A seismic station to monitor hydroacoustic waves. A T-phase station is typically located on steep-sloped islands and detects seismic signals that were converted from underwater sound waves or hydroacoustic waves when hitting land.  These stations are less effective for hydroacoustic monitoring but are less costly than hydrophone stations.

T-phase stations

Seismic stations to monitor hydroacoustic waves. A  T-phase station is typically located on steep-sloped islands and detects seismic signals that were converted from underwater sound waves or hydroacoustic waves when hitting land.  These stations are less effective for hydroacoustic monitoring but are less costly than hydrophone stations.

Tactical nuclear weapons

Short-range nuclear weapons, such as artillery shells, bombs, and short-range missiles, deployed for use in battlefield operations. Also called tactical nuclear weapons.

Tamper detector or Tamper Switch

Security devices installed at the entry of all seismic vaults. The purpose is to transmit information back to the central recording facilities in order to monitor remote stations for incidences of physical security breaches or other problems.

Teller

Edward Teller (1908-2003) is sometimes referred to as “the father of the hydrogen bomb.” He was a Hungarian-American physicist who played an active role in the Manhattan Project. Teller was an early supporter of developing thermonuclear weapons, and in the 1950s, he seized upon an idea from Stanislaw Ulam and with a few more modifications, created the workable design still used today. Teller advocated for continued nuclear testing and development throughout his life and lobbied hard against the test ban treaties.

Terabyte

A unit of computer memory or data storage capacity that is equal to 1,000 gigabytes.

Terabytes

Unit of computer memory or data storage capacity that is equal to 1,000 gigabytes.

Territory

Derived from the word “terra”, meaning “land, a territory is a defined area (including land and waters) considered to be in the legal possession of a person, organization, institution, state or country subdivision. As a country subdivision, a legally administered territory is a non-sovereign geographic area that has come under the authority of another government.

The 98% threshold (“gold standard”)

The requirement for station certification, as stated in the CTBT, dictating the percentage of valid data that must be transmitted from the remote station to the International Data Centre in Vienna.

Thermonuclear

In a thermonuclear warhead, the fusion of light nuclei, such as deuterium and tritium, contributes the main explosive energy. The high temperatures required for such fusion reactions are obtained by means of an initial fission explosion. It is also referred to as a hydrogen bomb. See also Fusion and Hydrogen bomb.

Thermonuclear weapon

A nuclear weapon in which fusion of light nuclei, such as deuterium and tritium, contributes the main explosive energy. The high temperatures required for such fusion reactions are obtained by means of an initial fission explosion. It is also referred to as a hydrogen bomb. See also Fusion and Hydrogen bomb.

Thirteen Practical Steps

Is an action plan to implement Article VI, the nuclear disarmament provision, of the NPT. They were adopted as part of the Final Document at the 2000 NPT Review Conference. The agreement included the "unequivocal undertaking" given by the nuclear-weapons states (NWS) to accomplish the total elimination of their nuclear arsenals leading to nuclear disarmament. The first and second steps concerned the Comprehensive Nuclear-Test-Ban Treaty: “1. The importance and urgency of signatures and ratifications, without delay and without conditions and in accordance with constitutional processes, to achieve the early entry into force of the Comprehensive Nuclear-Test-Ban Treaty; 2. A moratorium on nuclear-weapon-test explosions or any other nuclear explosions pending entry into force of that Treaty.”

Three-component stations

A seismic station that employs one seismic sensor measuring the three spatial components of seismic waves, i.e. up-down, East-West and North-South. This kind of seismic station measures both types of seismic waves - body and surface waves - to acquire information pertaining to the depth and strength of a seismic event. Three-component stations are less expensive to build because they use a single seismic sensor. Most stations in the auxiliary seismic network are three-component stations.

Threshold Test Ban Treaty

Between the former Soviet Union and the United States prohibits underground nuclear weapon tests having a yield exceeding 150 kilotons. The treaty was signed on July 3, 1974, and entered into force on December 11, 1990. It is officially called the "Treaty on the Limitation of Underground Nuclear Weapon Tests."

Timely data availability

The percentage of data from a station that reaches the International Data Centre within the allowable time delay per unit of time.

TNT

The explosive yield of TNT is considered the standard measure of strength of bombs and other explosives. TNT is a chemical compound, also known as trinitrotoluene, and is commonly used as an explosive for military and industrial applications. TNT is one of the most stable of high explosives and can be stored over long periods of time.

Transparency measures

The exchange of information, access to facilities, and cooperative arrangements states undertake to provide ready observation and verification of treaty or defense obligations, as well as other activities.

Treaty of Bangkok (Treaty on the Southeast Asian Nuclear-Weapon-Free-Zone)

Prohibits the development, manufacture, acquisition or testing of nuclear weapons anywhere within the region of the ten full-member parties: Brunei Darussalam, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand, and Vietnam. It also prohibits the transport of nuclear weapons through the region. Signatories also undertake to enact International Atomic Energy Agency safeguards and to refrain from dumping at sea, discharging into the atmosphere, or burying on land any radioactive material or waste. Opened for signature on 15 December 1995, the treaty entered into force on 27 March 1997. As of March 2008, all ten States Parties had ratified the treaty. However, none of the nuclear-weapon states (NWS) had yet signed the protocols.

Treaty of Pelindaba (Treaty on the African Nuclear-Weapon-Free-Zone)

Prohibits the research, development, manufacturing, stockpiling, acquisition, testing, possession, control, and stationing of nuclear explosive devices in the members' territory. The treaty also prohibits the deposit of radioactive waste originating from outside the continent within the region. Under the treaty, signatories are required to put all their nuclear programmes under International Atomic Energy Agency safeguards. The treaty also provides for the establishment of the African Commission on Nuclear Energy (AFCONE), which will supervise treaty implementation and ensure compliance. The treaty was opened for signature in Cairo on 11 April 1996. As of March 2008, there were 21 parties to the treaty: in addition 51 states had signed by not ratified it. China, France and the UK had ratified the treaty’s protocols while the Russian Federation and the United States had not ratified them.

Treaty of Rarotonga

From 1986 prohibits the testing, manufacturing, acquiring, and stationing of nuclear explosive devices in any member's territory. The treaty prohibits dumping radioactive wastes into the sea. In addition, the treaty requires all parties to apply International Atomic Energy Agency safeguards to all their peaceful nuclear activities. It was opened for signature on 6 August 1985, and entered into force on 11 December 1986. As of March 2008, there were 13 parties to the treaty: Australia, Cook Islands, Fiji, Kiribati, Nauru, New Zealand, Niue, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalul and Vanuatu. The treaty has three Protocols that refer to provisions of territories within the zone that belong to the United States, France, the United Kingdom, Russia, and China. All five nuclear weapon states have signed the protocols. 

Treaty of Tlatelolco

From 1969 created a nuclear-weapon-free zone in Latin America and the Caribbean and was the first international agreement that aimed at excluding nuclear weapons from an inhabited region of the globe. In addition to prohibiting nuclear testing by all States Parties, Member States also accept the application of International Atomic Energy Agency safeguards for all their nuclear activities to assist in verifying compliance with the treaty. The treaty also establishes a regional organization, the Agency for the Prohibition of Nuclear Weapons in Latin America (OPANAL), to help ensure compliance with its provisions. The treaty was opened for signature on 14 February 1967 and entered into force on 25 April 1969. It has since been signed and ratified by all 33 nations of Latin America and the Caribbean, with  Cuba being the last country to ratify it on 23 October 2002. China, France, the Netherlands, the Russian Federation, the United Kingdom and the United States have all signed the relevant protocols of the treaty.

Treaty on the Non-Proliferation of Nuclear Weapons

Signed in 1968, this multilateral Treaty aimed at limiting the spread of nuclear weapons in all its aspects entered into force on 5 March 1970 and is regarded as the “cornerstone of the nuclear non-proliferation and disarmament regime”. The three pillars of the Treaty are nonproliferation, disarmament and the peaceful use of nuclear technology. It separates Nuclear Weapon States (NWS) from Non-Nuclear Weapon States (NNWS). The Treaty on the Non-Proliferation of Nuclear Weapons (NPT)’s “central bargain” is that the NNWSs committed themselves not to “manufacture or otherwise acquire nuclear weapons or other nuclear explosive devices” (Article II of the NPT) while, in exchange, the NWS (i.e. the five countries that had conducted nuclear tests before 1967) committed themselves to share peaceful nuclear technology and to engage in disarmament negotiations aimed at the elimination of their nuclear arsenals. The preamble of the NPT recalls the determination expressed by the Parties to the Partial Test Ban Treaty to “seek to achieve the discontinuance of all test explosions of nuclear weapons for all time and to continue negotiations to that end.” As of January 2008, there were 190 Parties to the NPT (i.e. all except India, Israel, Pakistan and the DPRK, which announced its withdrawal from the Treaty in 2003).

Treaty on the South Pacific Nuclear-Weapon-Free Zone

From 1986 prohibits the testing, manufacturing, acquiring, and stationing of nuclear explosive devices in any member's territory. The treaty prohibits dumping radioactive wastes into the sea. In addition, the treaty requires all parties to apply International Atomic Energy Agency safeguards to all their peaceful nuclear activities. It was opened for signature on 6 August 1985, and entered into force on 11 December 1986. As of March 2008, there were 13 parties to the treaty: Australia, Cook Islands, Fiji, Kiribati, Nauru, New Zealand, Niue, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalul and Vanuatu. The treaty has three Protocols that refer to provisions of territories within the zone that belong to the United States, France, the United Kingdom, Russia, and China. All five nuclear weapon states have signed the protocols.

Trilateral Statement on the Non-Proliferation of Weapons of Mass Destruction and the Means of Their Delivery

Commits Ukraine to rid itself of nuclear weapons and to transfer 200 SS-19 and SS-24 warheads to Russia over a ten-month period. It was signed by Russian President Boris Yeltsin, Ukrainian President Leonid Kravchuk and U.S. President Bill Clinton, in January 1994. The Trilateral Statement also specifies that Ukraine is to deactivate its SS-24s within the same ten-month period. The United States and Russia agree to guarantee Ukraine's borders and grant Ukraine security guarantees as long as Ukraine joins the NPT as a non-nuclear weapons state.

Tsunami

A series of waves created when a body of water, such as an ocean, is rapidly displaced. Earthquakes, mass movements above or below water, volcanic eruptions and other underwater explosions, landslides, underwater earthquakes, large meteoroid or asteroid impacts, as well as testing with nuclear weapons at sea, all have the potential to generate a tsunami. Derived from the Japanese words for harbor and wave, a tsunami’s effects can range from unnoticeable to devastating (e.g. the December 2004 tsunami that wreaked havoc on many Indian Ocean coastal areas). (Source: Wikipedia)

Tsunamis

A series of waves created when a body of water, such as an ocean, is rapidly displaced. Earthquakes, mass movements above or below water, volcanic eruptions and other underwater explosions, landslides, underwater earthquakes, large meteoroid or asteroid impacts, as well as testing with nuclear weapons at sea, all have the potential to generate a tsunami. Derived from the Japanese words for harbor and wave, a tsunami’s effects can range from unnoticeable to devastating (e.g. the December 2004 tsunami that wreaked havoc on many Indian Ocean coastal areas). (Source: Wikipedia)

TTBT

Same as Threshold Test Ban Treaty