Editing Comprehensive Nuclear-Test-Ban Treaty (section)

==Monitoring==
[[Geophysics|Geophysical]] and other technologies are used to monitor for compliance with the Treaty: [[forensic seismology]], hydroacoustics, [[infrasound]], and [[radionuclide]] monitoring.<ref>{{Cite web|url=https://2009-2017.state.gov/t/avc/rls/212176.htm|title=CTBT: International Monitoring System|website=U.S. Department of State|access-date=2019-10-16}}</ref> The first three forms of monitoring are known as [[Waveform|wave-form]] measurements. Seismic monitoring is performed with a system of 50 primary stations located throughout the world, with 120 auxiliary stations in signatory states.<ref>{{Cite web|url=https://www.ldeo.columbia.edu/~richards/SeismoandCTBTVerif.html|title=Seismology and CTBT Verification|last=Richards|first=Paul|website=ldeo.columbia.edu|access-date=2019-10-16}}</ref> Hydroacoustic monitoring is performed with a system of 11 stations that consist of [[hydrophone]] triads to monitor for underwater explosions. Hydroacoustic stations can use seismometers to measure T-waves from possible underwater explosions instead of hydrophones.<ref>{{Cite web|url=https://acoustics.org/pressroom/httpdocs/144th/Lawrence.htm|title=A Global Network of Hydroacoustic Stations for Monitoring the Comprehensive Nuclear-Test-Ban Treaty|last=Lawrence|first=Martin|website=acoustics.org|access-date=2019-10-16}}</ref> The best measurement of hydroacoustic waves has been found to be at a depth of 1000 m. Infrasound monitoring relies on changes in atmospheric pressure caused by a possible nuclear explosion, with 41 stations certified as of August 2019. One of the biggest concerns with infrasound measurements is noise due to exposure from wind, which can affect the sensor's ability to measure if an event occurred. Together, these technologies are used to monitor the ground, water, and atmosphere for any sign of a nuclear explosion.<ref>{{Cite web|url=https://www.armscontrol.org/act/2009-09/building-up-regime-verifying-ctbt|title=Building Up the Regime for Verifying the CTBT {{!}} Arms Control Association|last=Tóth|first=Tibor|date=2019-08-01|website=armscontrol.org|access-date=2019-10-17}}</ref>

Radionuclide monitoring takes the form of either monitoring for radioactive particulates or [[noble gas]]es as a product of a nuclear explosion.<ref>{{Cite web|url=https://www.armscontrol.org/act/2008-10/features/comprehensive-test-ban-treaty-effectively-verifiable|title=The Comprehensive Test Ban Treaty: Effectively Verifiable {{!}} Arms Control Association|last=Hafemeister|first=David|date=2019-08-01|website=armscontrol.org|access-date=2019-10-17}}</ref> Radioactive particles emit radiation that can be measured by any of the 80 stations located throughout the world. They are created from nuclear explosions that can collect onto the dust that is moved from the explosion.<ref>{{Cite web|url=https://www.ctbto.org/verification-regime/monitoring-technologies-how-they-work/radionuclide-monitoring/|title=Radionuclide monitoring: CTBTO Preparatory Commission|website=ctbto.org|access-date=2019-10-17}}</ref> If a nuclear explosion took place underground, noble gas monitoring can be used to verify whether or not a possible nuclear explosion took place. Noble gas monitoring relies on measuring increases in radioactive [[xenon]] gas. Different isotopes of xenon include <sup>131m</sup>Xe, <sup>133</sup>Xe, <sup>133m</sup>Xe, and <sup>135</sup>Xe. All four monitoring methods make up the International Monitoring System (IMS). Statistical theories and methods are integral to CTBT monitoring providing confidence in verification analysis. Once the Treaty enters into force, on-site inspections will be conducted where concerns about compliance arise.<ref>{{Cite journal|last1=Ringbom|first1=Anders|last2=Miley|first2=Harry|date=2009-07-25|title=Radionuclide Monitoring|url=https://www.ctbto.org/fileadmin/user_upload/pdf/ISS_Publication/Radionuclide_23-28.pdf |archive-url=https://web.archive.org/web/20101019025518/http://www.ctbto.org/fileadmin/user_upload/pdf/ISS_Publication/Radionuclide_23-28.pdf |archive-date=2010-10-19 |url-status=live|pages=23–28|via=CTBTO}}</ref>

The [[Comprehensive Test Ban Treaty Organization Preparatory Commission|Preparatory Commission]] for the [[Comprehensive Test Ban Treaty Organization]] (CTBTO), an international organization headquartered in [[Vienna]], Austria, was created to build the verification framework, including establishment and provisional operation of the network of monitoring stations, the creation of an international data centre (IDC), and development of the on-site Inspection capability.<ref>{{Cite news|url=https://www.nti.org/learn/treaties-and-regimes/ctbto-preparatory-commission/|title=Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO Preparatory Commission) {{!}} Treaties & Regimes {{!}} NTI|newspaper=The Nuclear Threat Initiative|access-date=2019-10-18}}</ref> The CTBTO is responsible for collecting information from the IMS and distribute the analyzed and raw data to member states to judge whether or not a nuclear explosion occurred through the IDC. Parameters such as determining the location where a nuclear explosion or test took place is one of the things that the IDC can accomplish.<ref>National Academy of Sciences. 2002. ''Technical Issues Related to the Comprehensive Nuclear Test Ban Treaty''. Washington, DC: The National Academies Press. https://doi.org/10.17226/10471.</ref> If a member state chooses to assert that another state had violated the CTBT, they can request an on-site inspection to take place to verify.<ref>{{Cite journal|last=Nikitin|first=Mary|date=2016-09-01|title=Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments|url=https://fas.org/sgp/crs/nuke/RL33548.pdf |archive-url=https://web.archive.org/web/20060923055941/http://www.fas.org/sgp/crs/nuke/RL33548.pdf |archive-date=2006-09-23 |url-status=live|journal=Congressional Research Service}}</ref>

The monitoring network consists of 337 facilities located all over the globe. As of May 2012, more than 260 facilities have been certified. The monitoring stations register data that is transmitted to the international data centre in Vienna for processing and analysis. The data are sent to states that have signed the Treaty.<ref>{{cite web|url=http://www.ctbto.org/press-centre/press-releases/2009/us-nuclear-security-administrator-dagostinovisits-the-ctbto/|title=US nuclear security administrator dagostino visits the CTBTO|access-date=4 December 2011|date=15 September 2009|work=[[CTBTO Preparatory Commission]]|archive-url=https://web.archive.org/web/20120125015918/http://www.ctbto.org/press-centre/press-releases/2009/us-nuclear-security-administrator-dagostinovisits-the-ctbto/|archive-date=25 January 2012|url-status=live}}</ref>