a b s t r a c tSeismologists from Kazakhstan, Russia, and the United States have rescued the Soviet-era archive of nuclear explosion seismograms recorded at Borovoye in northern Kazakhstan during the period 1966-1996. The signals had been stored on about 8000 magnetic tapes, which were held at the recording observatory. After hundreds of man-years of work, these digital waveforms together with significant metadata are now available via the project URL, namely http://www.ldeo.columbia.edu/res/pi/Monitoring/Data/ as a modern open database, of use to diverse communities.Three different sets of recording systems were operated at Borovoye, each using several different seismometers and different gain levels. For some explosions, more than twenty different channels of data are available. A first data release, in 2001, contained numerous glitches and lacked many instrument responses, but could still be used for measuring accurate arrival times and for comparison of the strengths of different types of seismic waves. The project URL also links to our second major data release, for nuclear explosions in Eurasia recorded in Borovoye, in which the data have been deglitched, all instrument responses have been included, and recording systems are described in detail.This second dataset consists of more than 3700 waveforms (digital seismograms) from almost 500 nuclear explosions in Eurasia, many of them recorded at regional distances. It is important as a training set for the development and evaluation of seismological methods of discriminating between earthquakes and underground explosions, and can be used for assessment of three-dimensional models of the Earth's interior structure.

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This paper presents the travel times of P waves for 8 Yucca Flat (Nevada Test Site NTS) explosions from 1979 to 1984, with magnitudes mb = 4.9–5.9. Travel times were obtained by revising seismograms from the archives Sadovsky Institute of Geosphere Dynamics for the subsystem “Ozherel’e” (Necklace) of peripheral points Zerenda, Vostochniy, Chkalovo of the large-base seismic array system (SAS) of the geophysical observatory Borovoye. This system has been operating since 1979 on the territory of Kazakhstan. By the example of registration of underground nuclear explosions at the Yucca site of the Nevada Test Site (NTS), local travel time curves and linear trends in the P wave travel time in the range of epicentral distances 89.3110°–90.3701° are investigated. We estimate of the velocities of effective P waves for the Yucca-“Ozherel’e” and peripheral points.

During the Cold War of the 20th century and the classification of information between the largest nuclear states the Soviet Union (USSR) and the United States of America (USA), data on the registration of nuclear explosions were not published in the reports of the Unitied Seismic Observation Service. However, underground nuclear explosions were recorded. For example, underground nuclear explosions, produced by the United States on Amchitka island, were recorded by more than 30 stations of the USSR at epicentral distances Δ ~ 8–160°. Tests at the Nevada Test Site were found especially well throughout the USSR seismic stations. As a result of processing the bulletins of registered events, checking the values with the time service, the registration parameters for the Soviet stations were destroyed. However, thanks to an employee of the laboratory 5-s of the Institute of Physics of the Earth named after O.Yu. Schmidt of the USSR Academy of Sciences Kh.D. Rubinstein is kept at the Institute for the Dynamics of Geospheres of the Russian Academy of Sciences named after Academician M.A. Sadovsky. Only after 1985 messages from some seismic stations of the former USSR began to be published in the operational reports of the Geophysical Service of the Russian Academy of Sciences. This material is intended to publish that layer of invaluable information on the registration of underground nuclear explosions, made by the United States, which has been so carefully created for decades, and has not been published anywhere at the moment.

This paper shows the results of the refined locations for underground Peaceful Nuclear Explosions (PNEs). Peaceful nuclear explosions (PNEs) were made for industrial applications in the Soviet Union. This study is based on a comparison of PNEs’ parameters. These explosions were recorded by seismographic stations in Kazakhstan from 1966 to 1988. The monitoring/verification community generally utilizes PNE locations from Sultanov et al. (1999). In reality, there are errors and some PNEs are poorly located. Our locations were determined using an integrated approach encompassing published open literature sources and archive seismogram analysis from Borovoye Geophysical Observatory. Treated PNEs seismograms have been available to researchers since 2001. They became available after the cooperation between Russian and U.S. organizations. The first one was the Institute of Geosphere Dynamics of the Russian Academy of Sciences (IDG RAS), the organization that operated the Observatory in the Soviet era. The second one was the National Nuclear Center of the Republic of Kazakhstan (NNC since 1992). The third one, from the U.S. side, was the Lamont‒Doherty Earth Observatory of Columbia University (LDEO). We present two digital seismograms of old-style seismograms from a digitized archive in ASCII format. We provide travel times for P-waves, some seismograms, and additional source parameters.