Government Affairs Program SPECIAL UPDATE

AGU, SSA Release Joint Statement on Technical Feasibility of Monitoring Test Ban Treaty


This update was originally sent out as an e-mail message to AGI's member societies

IN A NUTSHELL: As the Senate prepares to vote on ratification of the Comprehensive Test-Ban Treaty (CTBT), the American Geophysical Union and the Seismological Society of America released a joint statement on October 6th expressing confidence "that the combined worldwide monitoring resources will meet the verification goals of the CTBT." Verification of the treaty is one of two major technical issues being raised by opponents of ratification. A Senate vote could take place as early as October 12th.


On Wednesday, October 6, the American Geophysical Union (AGU) and Seismological Society of America (SSA) held a press conference at AGU Headquarters in Washington, DC to announce the release of their joint statement on the Comprehensive Test Ban Treaty (CTBT). The announcement came as the Senate prepared for a showdown vote on ratification of the treaty. Although the AGU/SSA statement does not address whether or not the treaty should be ratified, it does address one of the major technical issues being raised in the debate -- whether or not the treaty is verifiable.

In his opening remarks at the press conference, AGU Executive Director Fred Spilhaus said that one reason for the release of the position statement was to inform the general public of the scientific aspects of the current CTBT policy debate. Three members of the drafting committee were present: Dr. Terry Wallace of the University of Arizona, who chaired the drafting committee and currently serves as President of SSA; Dr. Jeffrey Park of Yale University, a member of the AGU Council and president-elect of AGU's Seismology Section; and Dr. Gregory van der Vink, Director of Planning for the Incorporated Research Institutions for Seismology (IRIS) and a member of AGU's Committee on Public Affairs. The statement, entitled "Capability to Monitor the Comprehensive Test Ban Treaty," asserts that "the monitoring capability will continue to strengthen as more data are collected, more research is performed, and as global communication networks expand." The statement also emphasizes the importance of making all data collected by monitoring activities "openly available without any restriction or delay." The full text of the position statement can be found at the bottom of this update.

The two principal scientific issues associated with CTBT are stockpile stewardship and verification. The first centers on the ability of the DOE weapons laboratories (Los Alamos, Lawrence Livermore, and Sandia) to safely maintain the nuclear weapons stock pile without nuclear tests. The second is the ability to verify nuclear tests using a variety of means through the International Monitoring System (IMS) -- a set of seismic, hydroacoustic, radionuclide, and infrasound networks. The centerpiece of the IMS is the Global Seismographic Network (described by van der Vink in the past as a "global neighborhood watch").

Opponents of the treaty have called into question the ability of the United States to perform both these tasks. Earlier in the week, the Washington Post reported the Central Intelligence Agency's conclusion that "it cannot monitor low-level nuclear tests by Russia precisely enough to ensure compliance with the Comprehensive Test Ban Treaty." The CIA assessment of monitoring has been a focal point of the Republican senators' arguments against ratification.

The American Physical Society, which has endorsed the treaty, released a statement by 32 Nobel Prize-winning physicists earlier in the week supporting ratification. Included in the list of physicists are former designers of nuclear arms and leading public and private sector researchers. The group sent letters to every senator telling them not only of the importance of ratification, but also the need for congressional hearings before deciding on such an important global issue. The APS statement focuses on the ability of the United States to maintain the reliability of its stockpile of nuclear weapons without testing, principally through the development of very high-end computer simulation technology as part of the Department of Energy's stockpile stewardship program.

The Comprehensive Test Ban Treaty was signed on September 24, 1996, by President Clinton and the leaders of over 140 countries. It will not go into effect, however, unless a core group of 41 nuclear or nuclear-capable countries ratify it -- currently only 26 of the core group have ratified the treaty. The treaty was presented to the Senate in 1997 but no action has taken place principally due to the opposition of Senate Foreign Relations Committee Chairman Jesse Helms (R-NC).

Until this past month, Helms repeatedly insisted that CTBT would be considered only after the President presented the Kyoto climate change treaty to the Senate and after changes were made to the Anti-Ballistic Missile treaty. Following a major push by Senate Democrats to bring CTBT up for consideration, Helms dropped his opposition to a vote -- but not to the treaty -- and in late September, Majority Leader Trent Lott (R-MS) announced that a vote would be held after ten hours of debate on October 12th. Lott's move was in a sense calling the Democrats' bluff, because by all accounts the Republican leadership has the votes to defeat the treaty. Negotiations are ongoing between the Administration, Senate Democrats, and Senate Republicans, and it is not clear whether the vote will take place next week or be postponed, possibly until after the next presidential election.

Joint AGU/SSA Position Statement: Capability to Monitor the Comprehensive Test Ban Treaty

In September 1996, the United States was the first of 152 nations to sign the Comprehensive Test Ban Treaty (CTBT), an international agreement to ban all nuclear test explosions. The treaty is intended to impede the development of nuclear weapons as part of the international nonproliferation regime. The U.S has not yet ratified the treaty. As a result, many of its verification provisions have not yet been fully implemented. When implemented, the American Geophysical Union (AGU) and the Seismological Society of America (SSA) are confident that the combined worldwide monitoring resources will meet the verification goals of the CTBT.

The CTBT will be monitored by: 1) the national intelligence means of various countries, 2) the International Monitoring System (IMS) negotiated under the CTBT that consists of seismic, hydroacoustic, radionuclide, and infrasound networks, along with on-site inspections, and 3) the efforts of numerous independent scientists and institutions worldwide. It is this combination of resources that gives confidence in the ability to uncover CTBT violations. AGU and SSA believe that this overall monitoring capability will continue to strengthen as more data are collected, more research is performed, and as global communication networks expand.

The seismic component of the International Monitoring System is to consist of 170 seismic stations. This network is expected to detect all seismic events of about magnitude 4 or larger and locate those events within 1000 square kilometers (a circle with a diameter of approximately 35 km). This is the maximum area permitted by the treaty for an on-site inspection. A seismic magnitude of 4 corresponds to an explosive yield of approximately 1 kiloton (the explosive yield of 1,000 tons of TNT). AGU and SSA believe that the verification system, if built as planned, can be relied upon to meet that goal.

One of the biggest challenges to monitoring the CTBT is the possibility that testing could be successfully hidden by conducting nuclear explosions in an evasive manner. The concern is partly based on U.S. and Russian experiments which have demonstrated that seismic signals can be muffled, or decoupled, for a nuclear explosion detonated in a large underground cavity. The decoupling scenario, however, as well as other evasion scenarios, demand extraordinary technical expertise and the likelihood of detection is high. AGU and SSA believe that such technical scenarios are credible only for nations with extensive practical testing experience and only for yields of at most a few kilotons. Furthermore, no nation could rely upon successfully concealing a program of nuclear testing, even at low yields.

Data from the treaty's monitoring system will also contribute to our scientific understanding of the Earth and efforts to mitigate earthquake hazards. Article IV.A.10 of the treaty states "The provisions of this treaty shall not be interpreted as restricting the international exchange of data for scientific purposes". AGU and SSA support a broad interpretation of this article and strongly urge that all data from the International Monitoring System be made openly available without any restriction or delay.

Sources: AGU, APS, Washington Post

Special update prepared by Margaret Baker and David Applegate, AGI Government Affairs

Please send any comments or requests for information to the AGI Government Affairs Program.

Posted October 8, 1999

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