American Geophysical Union, Seismological Society of America reaffirm position statement on the Comprehensive Nuclear-Test Ban Treaty

29 June 2017

Joint Release

WASHINGTON, DC/ SAN FRANCISCO — Scientific research in Earth and space sciences advances our understanding of our world and contributes to strong global economies, security, and public health and safety. The American Geophysical Union (AGU) and Seismological Society of America (SSA) today announced a revision of their position statement, “The Capability to Monitor the Comprehensive Nuclear-Test-Ban Treaty (CTBT) Should be Expanded, Completed, and Sustained.

The Comprehensive Nuclear-Test-Ban Treaty is an international agreement to ban all nuclear explosions, and is intended to impede the development of nuclear weapons as part of the international nonproliferation regime. The treaty is not yet in effect because it has not been ratified by all the requisite countries—including the United States.

The AGU-SSA statement was updated to reflect changes over the past five years, including that 183 nations are now signatories and the continued development of the International Monitoring System (IMS) is now more than 85% complete and currently detecting and locating seismic events of at least a magnitude 4 anywhere in the world.

“The IMS and International Data Centre of the CTBT Organization Preparatory Commission are playing an important role in providing nations with data and expertise to monitor the world for nuclear explosions,” said Bill Walter, Ph.D., chair of the CTBT Review Task Force for AGU and SSA. “Data from IMS not only contribute to critical national security efforts but also to public safety by enhancing our global scientific understanding of the Earth and informing natural hazard mitigation efforts.

“Maintaining a high-quality global network of seismometers is vital for detecting and characterizing both open and clandestine nuclear explosions, as well as earthquakes and other natural hazards,” said SSA President-elect Peter Shearer, a professor of geophysics at U.C. San Diego.

The seven-person panel that reviewed and revised the position statement included:

  • Bill Walter, Lawrence Livermore National Laboratory (chair)
  • Stephen Myers, Lawrence Livermore National Laboratory
  • Paul Richards, Lamont-Doherty Earth Observatory, Columbia University
  • Brian Stump, Southern Methodist University
  • Raymond Jeanloz, University of California, Berkeley
  • Keith Koper, University of Utah
  • Thorne Lay, University of California, Santa Cruz

AGU and SSA maintain position statements to provide scientific expertise on significant policy issues related to the understanding and application of their members’ scientific disciplines.

The revised position statement was adopted by AGU’s Board and Council on June 29, 2017, and by SSA’s Board on April 17, 2017. The Seismological Society of America and the American Geophysical Union originally issued the joint position statement on the seismic verification of the Comprehensive Nuclear Test-Ban Treaty (CTBT) in 1999. The statement was reviewed and reaffirmed by both organizations in 2003, 2007, 2012 and was endorsed by the Geological Society of America in 2009.

Learn more about AGU position statements.

Learn more about SSA position statements.



The American Geophysical Union is dedicated to advancing the Earth and space sciences for the benefit of humanity through its scholarly publications, conferences, and outreach programs. AGU is a not-for-profit, professional, scientific organization representing 60,000 members in 137 countries. Join the conversation on FacebookTwitterYouTube, and our other social media channels.

The Seismological Society of America is a scientific society devoted to the advancement of earthquake science. Founded in 1906 in San Francisco, the Society now has members throughout the world representing a variety of technical interests: seismologists and other geophysicists, geologists, engineers, insurers, and policy-makers in preparedness and safety.

Notes for Journalists

A subject matter expert will be available for comment. Members of the press should contact AGU’s Strategic Communications team or Becky Ham at SSA to schedule an interview.

Please note that panel members’ affiliations are provided for identification purposes only. The position statement reflects a consensus view of the scientific societies and not necessarily any of the panel members’ employers.

AGU Contact:

Caitlyn Camacho, 202-777-7423, [email protected]
Josh Speiser, 202-777-7444, [email protected]

SSA Contact:

Becky Ham, 602-300-9600, [email protected]