From 1949 to 1989, Semipalatinsk was scrutinized furtively by U2 spy planes, satellites and seismologists hoping to learn more about the Soviet Union’s weapons capabilities. Now, for the first time, researchers can compare the information gleaned from these operations with the actual records from the test site to see how accurate Western researchers were in predicting the number and size of Semipalatinsk’s nuclear detonations.
The treasure trove of data from Semipalatinsk are especially important in light of the fact that only three nuclear tests—back-to-back tests in India and Pakistan in 1998 and a 2006 test in North Korea--have been conducted since the Comprehensive Nuclear Test Ban Treaty of 1996, said Paul Richards of Lamont-Doherty Earth Observatory of Columbia University.
As nuclear monitoring techniques have improved over the past ten years, “there has also been a lack—thank goodness—of weapons tests to actually record, from which to gain monitoring experience,” Richards, an expert in using seismological methods to detect nuclear tests, said. “It is therefore helpful in training ourselves today, in the work of monitoring, to look back at monitoring efforts in the past --- to see how well we did and what the challenges were.”
The first nuclear detonations near Semipalatinsk in the 1940s were above ground, and the U.S. Air Force collected atmospheric traces of the explosions. Testing moved underground in later decades, and seismological data became the primary way of monitoring the tests. In all, 456 nuclear tests took place at the site, with the last occurring in 1989. The veil of secrecy surrounding the site was lifted in the 1990s, when details of the tests were published in numerous books and scientific papers in Russia and Kazakhstan.
By comparing historical monitoring data with information from the new publications, Richards and colleagues can determine which underground tests were detected through seismic data at great distances, versus which kinds of tests would be detected by regional seismic stations today. They can also compare the monitors’ estimates of weapons yield—the size of the explosions—with the official estimates in the publications.
So far, the comparisons suggest “that today we can do a very good job indeed” of monitoring nuclear tests using seismological and other data, Richards said.
The new publications also offer a glimpse at how the Soviet-era nuclear program was organized and led, how radioactivity from the explosions affected people and animals, and how the overall environmental health of the area was altered by decades-long testing, he noted.
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Earth Sciences
19.07.2018 | Power and Electrical Engineering
19.07.2018 | Materials Sciences