Der Kernwaffenteststopp-Vertrag (CTBT) ist ein internationales Abkommen zum weltweiten Verbot von Kernwaffenversuchen – sowohl unterirdisch als auch unter Wasser und in der Atmosphäre, gleich ob für zivile oder militärische Zwecke. Der Vertrag wurde auf der Abrüstungskonferenz der Vereinten Nationen in Genf ausgehandelt und liegt seit 1996 zur Unterschrift aus. Er tritt in Kraft, sobald alle 44 Staaten, die im Besitz von Nukleartechnologie sind (und im Annex 2 des Vertrages namentlich genannt werden), ihn unterschrieben und ratifiziert haben. Ein internationales Überwachungssystem (IMS) mit über den Globus verteilten Messstationen soll die Einhaltung des Vertrages sicherstellen.
Deutschland unterzeichnete den Vertrag 1996, ratifizierte ihn 1998 und verpflichtete sich damit zur Einrichtung eines Nationalen Datenzentrums (NDC) und zum Aufbau und Betrieb von fünf Messstationen im Rahmen des IMS.
Zunächst wird ein Überblick über die Geschichte des Kernwaffenteststopp-Verfahrens, über dessen Verifikation und Implementierung in Deutschland gegeben. Dann werden die fünf deutschen IMS-Stationen sowie die Überwachungstechnologien Seismologie, Infraschall, Hydroakustik und Radionuklide vorgestellt. Um die Anwendung dieser Technologien im Rahmen der Aufdeckung nuklearer und nicht-nuklearer Ereignisse sowie um ausgewählte Test- und Anwendungsfälle des Überwachungssystems geht es im Weiteren. Dazu zählen die Kernwaffentests Nordkoreas zwischen 2006 und 2016, die NDC-Bereitschaftsübungen von 2007 bis 2013, das Tohoku-Erdbeben mit Tsunami und dem Reaktorunfall 2011 und der Meteorit von Tscheljabinsk 2013.
Andere Beiträge befassen sich mit Qualitätsanalysen der Wellenformprodukte des internationalen CTBT-Datenzentrums, mit den Potenzialen der Satelliten-Fernerkundung, der Bedeutung von Vor-Ort-Inspektionen (OSI ) sowie der seismischen Nachbebenüberwachung (SA MS) bei der Untersuchung möglicher CTBTVertragsverletzungen als letzten Schritt in der Verifikationskette.

For decades, the nuclear weapons capability of different countries was tracked in part via the interpretation of signals from more than 2000 nuclear test explosions that were conducted in programs of weapons development. The first such explosion took place in July 1945 (in New Mexico, USA, prior to the use of nuclear weapons in World War 2 against Japan). The last nuclear test, prior to the Comprehensive Nuclear-Test-Ban Treaty (CTBT) becoming open for signature in September 1996, was in July 1996 (in China). This treaty, which took nearly forty years to negotiate, has been signed by 184 states as of December 2018, but a few key additional signatures and ratifications are still needed before nuclear tests are banned under international law. The evidence that a nuclear test explosion has occurred can come from electromagnetic, seismic, hydroacoustic and infrasonic waves; and from unusual radionuclides—which can be present in particulate matter and/or as noble gases. Of course there is a vast infrastructure associated with military programs of nuclear weapons development in a limited number of countries. Less well-known, is the existence of a large infrastructure involving national and international efforts to monitor for the possible occurrence of nuclear test explosions, and thus to support CTBT verification.
This book does a very good job of explaining much of that work, as it is conducted in practice by a western nation with sophisticated facilities.
Beginning early in the cold war, the effort to detect and interpret signals from nuclear testing became a driving force that influenced the development of geophysics and geochemistry. In particular, seismology—the most quantitative of geophysical sciences—has been strongly shaped by investments needed to monitor not only earthquakes, but nuclear test explosions. The experience acquired for more than 50 yr prior to finalizing the CTBT, from monitoring nuclear tests in the atmosphere, underwater, in space, and under-ground, is now being put to the very different purpose of supporting a major initiative in nuclear arms control. A principal goal of the CTBT has always been to provide a restraint on nuclear weapon states—inhibiting further technical advances in weaponry — that in some respects balances the obligation of non-nuclear weapon states, under the Non-Proliferation Treaty, not to acquire nuclear explosion technology. Because of its extensive verification provisions, the CTBT is arguably the most complex of all nuclear arms control treaties. This book gives practical details of the monitoring system, as seen from the perspective of a country, Germany, with experience in all the key monitoring technologies deployed globally.
The CTBT has become associated with a huge reduction in nuclear testing. Since 1996 a handful of test explosions was carried out by India and Pakistan in May, 1998. But only North Korea has tested so far in the present century. Today, the monitoring capability accumulated in decades since 1945 is being applied not only for purposes of characterizing the limited number of nuclear test explosions which have been conducted since 1996, but for building confidence that CTBT signatories are honoring their obligation not to engage in nuclear testing. This treaty could not have come about, unless monitoring capability was deemed credible. And the book here under review explains in some detail how the practical work of monitoring is done, using several different technologies—of which seismology is the most important, because of its utility in characterizing nuclear tests in the environment that in practice has proved hardest to monitor, namely, underground.
So: a serious subject. And here we have a serious book, laying out features of the International Monitoring System (IMS) and the International Data Centre (IDC), both of them operated by the CTBT Organization (CTBTO), headquartered in Vienna, Austria. The IMS organizes the global operation of more than 300 stations and acquires their data, which is transmitted via a Global Communications Infrastructure to Vienna. There, the data streams are analysed at the International Data Centre (IDC), which issues a variety of reports on global activity, pertinent to the possibility — or the actuality — of a nuclear explosion having occurred. These reports are communicated back to state signatories, many of which operate National Data Centres (NDCs) that can both contribute to IMS station operations, and receive technical information from the IDC.
This book explains the work of the German NDC in a series of fourteen chapters that present the challenges and successes of monitoring for an activity that in recent years has been happening only in North Korea. Introductory material is followed by chapter 1 on general aspects of CTBT verification, and chapter 2 on specific details of operating Germany’s five IMS stations (two that acquire seismic data, two infrasonic and one for radionuclides). Four chapters then follow, on the four IMS/IDC technologies, namely seismic, infrasonic, hydroacoustic and radionuclide monitoring. Chapter 7 describes data that enabled verification of North Korea’s first five nuclear test explosions (2006–2016), and chapter 8 is on exercises to ensure the preparedness of NDCs to do their work. Our active planet exhibits a variety of natural phenomena that can sometimes be well-characterized, for a global audience, by IMS data and its analysis by the IDC. Important examples are described, in chapter 9 about the offshore Tohoku, Japan, M 9 earthquake of 11 March 2011, its tsunami, and the radionuclide releases from tsunami-damaged nuclear reactors at Fukushima; and then in chapter 10 on the huge explosion (comparable to half a megaton of TNT) of a meteorite on 15 February 2013, in the atmosphere above Chelyabinsk, Russia, which generated infrasound detected by half the global IMS infrasound network. Chapter 11 outlines standard data products generated by the IDC, which are important not only for the direct evidence they present, of phenomena (both nuclear explosive and non-nuclear), characterized by the IMS stations, but also for the guidance they provide to enable acquisition of non-IMS data — potentially available from some of the thousands of ground-based stations and satellites operated for purposes having nothing directly to do with CTBT monitoring, but which by happenstance were in the right place and at the right time to acquire data from events of interest on the basis of IMS data. Such non-IMS data have sometimes proved helpful in the interpretation of events reported by the IDC. And finally chapters 13 and 14 concern technologies being developed to supplement IMS data, if an on-site inspection (OSI) were to be conducted for purposes of clarifying the nature of an event which had been deemed suspicious, on the basis of remote data acquired by the IMS and perhaps by other stations. The framework within which OSIs can be requested and carried out, is predicated on the CTBT being formally in effect. That political situation may now seem far away—but then, it once seemed (in the 1960s, 1970s and 1980s) that the CTBT would never even be negotiated. Even in the cold war, efforts to control nuclear weapons went forward and influenced international policy. Such efforts sometimes moved rapidly in the aftermath of international concerns over specific crises — for example, the Atmospheric Test Ban Treaty of 1963 followed the clash over Soviet missiles discovered in Cuba in 1962. The book has some mistakes (the Soviet Union carried out 715 nuclear tests, not ‘more than a thousand’; the auxiliary network of seismographic stations in practice generates an available data stream that is continuous); and it was published before the sixth — and by far the largest — North Korean nuclear test, of September 3, 2017. It would be helpful if the publisher—Germany’s Institute for Geosciences and Natural Resources—put corrections and updates on a BGR website. But in general the quality of the material is high. The CTBT is a serious and historic effort that attempts to control further development of nuclear weapons. It could be put formally into place in a short period of time — if conditions become ripe — in part because of the extensive preparatory work, rooted in the geosciences, described in this book.

Paul G. Richards, Lamont-Doherty Earth Observatory of Columbia University, New York, USA.

Geophysical Journal International (2019) 217, p. 485-486