Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Great Progress Made by Seismologists in Identifying Violations of Nuclear Test Ban Treaty


Advances in detection devices and methods of analysis have allowed seismologists to identify virtually all events that might be nuclear explosions of possible military significance under the Comprehensive Test Ban Treaty (CTBT), according to Prof. Lynn R. Sykes of Columbia University’s Lamont-Doherty Earth Observatory. Writing in the 29 October issue of Eos, published by the American Geophysical Union, Sykes analyzes 72 questionable events since 1960.

Verification was a major issue in the U.S. Senate debate in 1999, in which American ratification of the treaty was defeated. Since 1995, the International CTBT Organization has detected many small seismic events and has determined that many were earthquakes or otherwise identifiable. Under the treaty, however, the international organization is not charged with identifying all seismic events and is, in fact, not permitted to declare an event a nuclear explosion. Unresolved cases and possible nuclear events are referred to national CTBT agencies, whose work is usually classified.

Therefore, says Sykes, we do not always know how well the difficult cases are resolved. Only 72 events have been flagged in the literature or by the media as questionable or difficult to identify, a small fraction of all events recorded over the past 42 years, demonstrating the great progress made in verification, says Sykes. By studying technical characteristics of the seismic signals, nearly all of the 72 events have been identified as nuclear explosions, chemical explosions, earthquakes, or mine collapses, he writes.

Thirty years ago, problem events registered seismic magnitudes (mb) of 4.3 to 5.6, whereas today, most attention is focused on the mb 2.0 to 3.5 level. Since the magnitude scale is logarithmic, this represents an improvement factor of 300 in the size of signals that can be identified. It means that nuclear explosions 1,000 times smaller in their energy release can now be identified, says Sykes.

Since 1990, all of the problem events greater than mb 2.5 have received special study and have been identified. There is no evidence, says Sykes, that any countries have exploded nuclear devices since the CTBT was opened for signature in 1996, aside from India and Pakistan (which have not signed). Under the International Monitoring System, which began in 1995, seismic monitors have been placed close to, or in, countries that possess nuclear weapons, and the shorter the distance high frequency seismic signals have to travel, the better the identification of their source, Sykes writes.

Indian nuclear explosions on May 11, 1998, and Pakistani ones later that month were widely recorded and quickly identified. Sykes says the Indian claim of two tests with a combined yield of 0.6 kilotons on May 13, 1998, is surely exaggerated, as they created no detectable seismic signal. Similarly, media reports in 2001 of an Iraqi nuclear explosion in 1989 appear to be false, Sykes writes, as no seismic signal was produced.

Regarding suspected Russian tests on September 8 and 23, 1999, at Novaya Zemlya, Sykes concludes that, if they occurred at all, they were very tiny, that is, 0.001 to 0.02 kilotons. They may have been so-called "sub-critical" tests that release no nuclear energy, which are permitted by the treaty. Russia, China, and the United States have each conducted sub-critical tests since the treaty was signed in 1996. Sykes notes that to have military significance, tests must produce yields of at least five to 10 kilotons.

As for the future of verification, Sykes says that only on-site inspections can resolve any doubt in suspected events where the nuclear yield is zero, and this becomes possible once the CTBT enters into force. Short of that, occasional problem events may occur at the limits of detection. These will become fewer, as investigations of previous questionable events are published and the science of verification advances further, he concludes.

Contact: Harvey Leifert
(202) 777-7507

Harvey Leifert | AGU

More articles from Earth Sciences:

nachricht Gas hydrate research: Advanced knowledge and new technologies
23.03.2018 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

nachricht New technologies and computing power to help strengthen population data
22.03.2018 | University of Southampton

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>