Verification Seismology
What is Verification?
The term 'verification' stands for 'verifying or confirming that
something is 'true'. In the case of nuclear explosions, verification
means that experts are expected to tell authorities and the public,
whether some detected phenomena had its origin in a natural source or
in a nuclear explosion. 'Seismic verification' means that the
discrimination between an earthquake and a nuclear explosion (typically
an underground nuclear explosion) is done on the basis of seismic
signals (measured with a seismograph).
Towards a Comprehensive Nuclear-Test-Ban Treaty
The Conference on Disarmament (CD) in Geneva negotiated aComprehensive-Test-Ban Treaty (CTBT) that would prohibit any nuclear
explosions. Mainly due to objections by India, no consensus was
reached. Australia and other countries then took the draft treaty to
New York to the UN General Assembly. On September 10, 1996, a majority
of 158 States voted in favour of such a treaty. On 24 September 1996
the CTBT (Treaty Text and its ) was presented for signature and
was signed by many States.
The Verification System
In order to verify compliance with the treaty, an International Monitoring System (IMS) will be established. The IMS shall comprise seismological, hydroacoustic, radionucleide, and infrasound monitoring and respective means of communication, and be supported by the International Data Centre (IDC) of the Technical Secretariat.
The Seismological Monitoring System
An important part of this IMS will be the seismic monitoring system. Underground nuclear explosions generate seismic waves similar to waves caused by earthquakes and can therefore be recorded by seismic stations. A map shows the distribution of the IMS network: plotted are the primary stations (blue squares), the auxiliary stations (yellow triangles), and 20'224 epicenters as determined during 1995 by the prototype IDC (pIDC) during GSETT-3.
Group of Scientific Experts and GSETT-3
The CD has established a Group of Scientific Experts (GSE) with the task to develop a system to detect and identify seismic events. Such an experimental system is in operation since 1 January 1995 (GSETT-3: Group of Scientific Experts' Technical Test 3). During 1996 the GSETT-3 network will gradually be modified and should approach the IMS network configuration. Since 1990 the GSE has developed a comprehensive set of data exchange formats that are also widely used for other seismological purposes. The documentation can also be found on
