Download or read book Seismic Identification Analyses of Cavity Decoupled Nuclear and Chemical Explosions written by John R. Murphy and published by . This book was released on 1994 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Comparative Analysis of the Seismic Characteristics of Cavity Decoupled Nuclear and Chemical Explosions written by and published by . This book was released on 1995 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Successful seismic monitoring of any eventual Comprehensive Test Ban Treaty will require the development of a capability to identify signals from small cavity decoupled nuclear explosions from among the numerous signals to be expected from earthquakes, rockbursts and chemical explosion (CE) events of comparable magnitude. The investigations summarized in this report center on a variety of comparative analyses of observed and simulated seismic data corresponding to decoupled nuclear explosions with data recorded from both tamped and near-surface, ripple-fired CE events. More specifically, seismic data recorded from cavity decoupled nuclear tests in both the U.S. and former Soviet Union are used to assess the relative seismic coupling efficiencies of the different types of CE events and to evaluate potential seismic discriminants which might be used to identify the various source types. The results of these comparison studies indicate that tamped CE events with yields on the order of 7 tons and ripple fired CE events with yields in the 70-100 ton range can be expected to produce near-regional ground motion levels comparable to those expected from fully decoupled 1 kt nuclear explosions at Azgir.

Download or read book Analyses of the Seismic Characteristics of U S and Russian Cavity Decoupled Explosions written by and published by . This book was released on 1994 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents a summary of the initial results of an on-going joint research program in which S-CUBED scientists are working with Russian scientists from the Institute for Dynamics of the Geospheres in an attempt to develop a better understanding of the effects of cavity decoupling on the seismic signals produced by underground nuclear explosions. This program includes analyses of seismic data recorded from a series of 10 tamped and 12 decoupled HE tests which were conducted in cavities of different sizes and shapes in Kirghizia in 1960, a theoretical evaluation of the influence of radiation diffusion effects on nuclear cavity decoupling efficiency and an analysis of data recorded from six small (0.01 to 0.50 kt) Russian nuclear tests conducted in a 32 m radius, water-filled cavity in salt at the Azgir test site. (MM).

Download or read book Analysis and Simulation of Cavity Decoupled Chemical Explosions written by and published by . This book was released on 2003 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: We analyze data from two sets of decoupled chemical explosions. NORSAR has obtained data from seven decoupled chemical explosions conducted from 1987-2002 in Alvdalen, Sweden, recorded both in he near field and on regional seismic stations NORES, HAGFORS, and NORSAR. The explosions were conducted in three granite chambers at a depth of approximately 100 meters in chambers with volumes of 200, 300 and 1000 m and yields ranging from 2500 kg to 10,000 kg. The smallest explosion in the largest chamber is almost fully decoupled while the other explosions are partially coupled, overdriven by up to a factor of 25. The data show that decoupling remains fairly constant for overdrive up to about a factor of 10, then decreases rapidly at higher yields. 1D and 3D simulations of these explosions are performed to model the data. IDG has digitized a set of surface seismic data recorded from a series of Soviet high-explosive cavity decoupling tests conducted in a mine in Kirghizia in the summer of 1960.

Download or read book High Frequency Seismic Source Characteristics of Cavity Decoupled Underground Nuclear Explosions written by J. R. Murphy and published by . This book was released on 1988 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research investigated the high frequency characteristics of the seismic sources corresponding to cavity decoupled nuclear explosions and to assess the implications of these investigations with regard to the detection and discrimination of small decoupled explosions. This study has been carried out using a combination of deterministic simulations and analyses of empirical data recorded from selected cavity decoupled explosions. With regard to the deterministic simulations, a series of nonlinear finite difference calculations have been performed to simulate cavity decoupled explosions in unsaturated tuff and salt emplacement media. These simulations have confirmed the fact that the simple step pressure approximation is not valid at high frequencies and that the initial pressure spike on the cavity wall can induce significant nonlinear response. Preliminary analyses of high frequency seismic data recorded from the STERLING decoupled explosion in salt and the MILL YARD decoupled explosion in unsaturated tuff have provided evidence that the high frequency source components associated with the complex cavity pressure loadings do effectively couple into the seismic regime, in agreement with the predictions of the nonlinear finite difference simulations.

Download or read book Developments in the Field of Detection and Identification of Nuclear Explosions Project Vela and Relationship to Test Ban Negotiations written by United States. Congress. Joint Committee on Atomic Energy and published by . This book was released on 1962 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regional Seismic Detection Analyses of Selected Soviet Peaceful Nuclear Explosions written by and published by . This book was released on 1996 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic detection of small, evasively tested underground nuclear explosions remain as a major challenge to effective verification of any eventual CTBT. Most seismic detection research reported to date has focused on analyses of regional seismic signals recorded from explosions at the few known nuclear weapons test sites and, consequently, represent only limited ranges of the source and propagation path conditions of potential monitoring interest. In this study, we analyze regional seismic data recorded at the Borovoye station in Central Asia from a selected group of Soviet PNE tests which sample wider ranges of the source and propagation path variables of interest. The results of these analyses have indicated that it will in general be difficult to seismically detect low-yield, cavity decoupled nuclear explosions, even with high quality stations at regional distance of 100 or less, and that additional research will be required to optimize the seismic networks and signal processing systems needed to monitor such clandestine tests.

Download or read book Developments in the Field of Detection and Identification of Nuclear Explosions Project Vela and Relationship to Test Ban Negotiations written by United States. Congress. Joint Committee on Atomic Energy and published by . This book was released on 1962 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of the Seismic Characteristics of U S and Russian Cavity Decoupled Explosions written by J. R. Murphy and published by . This book was released on 1995 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cavity decoupling evasion scenario remains as the greatest challenge to effective seismic monitoring of any eventual CTBT. However, despite the fact that the feasibility of this evasion concept was experimentally established nearly 30 years ago by the U.S. STERLING test, a number of issues of importance with respect to seismic monitoring still remain unresolved. In an attempt to address some of these issues, we have been working with scientists from the Russian Institute For Dynamics of the Geospheres to integrate the limited U.S. and Russian data and modeling experience into a uniform database on cavity decoupling. During the past year, our research has centered on analyses of data recorded from an extensive series of Russian HE cavity decoupling tests conducted in Kirghizia in 1960 and on analyses of seismic data recorded from six Russian nuclear tests conducted in a water-filled cavity at Azgir. The Kirghizia HE cavity decoupling series consisted of 10 tamped and 12 cavity tests in limestone, and included tests of the same yield in both spherical and nonspherical cavities of equal volume. Comparisons of near-field seismic data recorded from these tests indicate that the low frequency decoupling effectiveness is approximately independent of cavity shape for roughly cylindrical cavities with length to width ratios of 6 or more, in agreement with previous theoretical simulation results. Spectral analyses of waveform data recorded at the same distances from 1.0 ton tamped explosions and from a 1.0 ton decoupled test in a spherical cavity with a radius of 2.88 m indicate a maximum low frequency decoupling factor of about 25 for this test.

Download or read book Syllabus of On site Inspection of Unidentified Seismic Events written by Stanford Research Institute and published by . This book was released on 1961 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Further Studies of the Seismic Characteristics of Russian Explosions in Cavities Implications for Cavity Decoupling of Underground Nuclear Explosions written by and published by . This book was released on 1996 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report provides a summary of the results of a joint research program under which scientists from S-CUBED have been working with scientists from the Russian Institute for Dynamics of the Geospheres in an attempt to develop a better understanding of the effects of cavity decoupling on the seismic signals produced by underground nuclear explosions. Investigations conducted under this program have focused on analyses of seismic data recorded from a series of HE cavity decoupling experiments conducted by the Russians in Kirghizia in 1960, and from a sequence of nuclear tests conducted in a water-filled cavity at the Soviet Azgir test site during the period 1975-1979. The Kirghizia series included tests designed to assess the influence of cavity geometry on decoupling effectiveness, and comparisons of near-field seismic data recorded from these tests indicate that the low frequency decoupling factor is independent of cavity shape for elongated cavities with length to width ratios of 6 or more, in agreement with previous theoretical simulation results. Broadband seismic data recorded from the Azgir water-filled cavity tests are analyzed to estimate cavity/tamped source spectral ratios, and the results are compared with theoretical finite difference simulations of these tests.

Download or read book LLNL State of the art Codes for Source Calculations written by and published by . This book was released on 1995 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The explosion-source region is defined as the region surrounding an underground explosion that cannot be described by elastic or anelastic theory. This region extends typically to ranges on the order of 1 km/kt. For the simulation or analysis of seismic signals, what is required is the time resolved motion and stress state at the inelastic boundary. Various analytic approximations have been made for these boundary conditions, but since they rely on near-field empirical data they cannot be expected to reliably extrapolate to different explosion sites. More important, without some knowledge of the initial energy density and the characteristics of the medium immediately surrounding the explosion, these simplified models are unable to distinguish chemical from nuclear explosions, identify cavity decoupling, or account for such phenomena as anomalous dissipation via pore collapse. The purpose here is to document the state-of-the-art codes at LLNL involved in simulating underground (chemical and nuclear) explosions and, in so doing, present an overview of the physics. In what follows, the authors first describe the fundamental equations involved, discuss solution methods, coordinate frames and dimensionality. Then they identify the codes used at LLNL and their limitations. A companion report will describe the factors that most influence the seismic response, i.e., the source properties important for discrimination. That report will emphasize the coupling between the rock properties and the characteristics of the explosion cavity.

Download or read book Monitoring the Comprehensive Nuclear Test Ban Treaty Source Processes and Explosion Yield Estimation written by Goran Ekstrom and published by Springer Science & Business Media. This book was released on 2001-12-01 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pure appl. geophys., by 161 nations. Entry of the treaty into force, however, is still uncertain since it requires ratification by all 44 nations that have some nuclear capability and, as of 15 June 2001, only 31 of those nations have done so. Although entry of the CTBT into force is still uncertain, seismologists and scientists in related fields, such as radionuclides, have proceeded with new research on issues relevant to monitoring compliance with it. Results of much of that research may be used by the International Monitoring System, headquartered in Vienna, and by several national centers and individual institutions, to monitor compliance with the CTBT. New issues associated with CTBT monitoring in the 21st century have presented scientists with many new challenges. They must be able to effectively monitor com pliance by several countries that have not previously been nuclear powers. Effective monitoring requires that we be able to detect and locate much smaller nuclear events than ever before and to distinguish them from small earthquakes and other types of explosions. We must have those capabilities in regions that are seismically active and geologically complex, and where seismic waves might not propagate efficiently.

Download or read book Technical Aspects of Detection and Inspection Controls of a Nuclear Weapons Test Ban written by United States. Congress. Joint Committee on Atomic Energy and published by . This book was released on 1960 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identification of Seismic Sources Earthquake or Underground Explosion written by Eystein S. Husebye and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 867 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of this NATO Advanced Study Institute was seismic monitoring under a nuclear test ban - an application of scienti fic knowledge and modern technology for a political purpose. The international political objective of a comprehensive nuclear test ban provided in turn the motivation for our technical and scientific discussions. In order to obtain a historical perspec tive on the progress of the work towards a comprehensive test-ban treaty (CTB), it is necessary to go back to 1958, when a confer ence of scientific experts in Geneva made the first steps toward an international seismic monitoring system. However, agreement on actual capabilities of a monitoring system for verifying compliance with such a treaty was not achieved, and thus the conference did not lead to immediate political results. After the Partial Test Ban Treaty of 1963, which banned nuclear explosions in the atmosphere, outer space and under the seas, renewed interest in the seismological verification of a CTB took place. A number of countries initiated large-scale research efforts toward detecting and identifying underground nuclear explosions, and it was in this context that the large aperture seismic arrays NORSAR and LASA were established. This type of development resulted in excellent seismic data in digital form and was thus of great irnprotance to the seismological com munity.

Download or read book Monitoring a Comprehensive Test Ban Treaty written by Eystein S. Husebye and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 843 pages. Available in PDF, EPUB and Kindle. Book excerpt: An international treaty banning the testing of any nuclear device in any environment - a comprehensive test ban treaty (CTBT) - has been on the political agenda for nearly 40 years. Objections to a CTBT have been political, technical, or a combination of both. However, the possibilities seem better after the end of the Cold War. In the prevailing, cooperative disarmament climate a CTBT appears likely to be approved by most countries in 1996. Hence the great current interest in monitoring technologies and capabilities. Such issues are comprehensively addressed here, a preamble being devoted to the political developments and setbacks over the past 40 years. Since seismic means are considered the dominant monitoring element, they are explored in detail. Contributions cover network deployments, advanced signal processing, wave propagation in heterogeneous media, and seismic source representations, and a variety of techniques for source classification (including neural networks). Complementary monitoring techniques, such as hydroacoustics, radionuclides and infrasound, are also summarised. The IAEA operation for monitoring compliance with the Non-Proliferation Treaty is also presented. The book also includes eyewitness accounts of the Soviet 50 Mt megabomb development and test, as well as the efforts made by the state to monitor the nuclear test programmes of the western powers. Includes some 33 articles written by distinguished scientists active in CTBT monitoring research for decades.

Download or read book Investigation of Regional Seismic Discrimination Issues for Small Or Decoupled Nuclear Explosions written by and published by . This book was released on 1994 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goals of lowering the seismic threshold for underground nuclear explosions to magnitudes near 2.5 m sob o and extending the capability to other geographical regions will require utilization of regional stations for detection and identification. However, regional techniques have seldom been tested on small nuclear explosions. Therefore, S-CUBED is conducting a research program aimed at the identification problems associated with small or decoupled nuclear explosions near a low monitoring threshold (e.g. 1-kt fully decoupled or about 2.5 mb). Initial efforts have focused on using source scaling procedures to scale down records from larger explosions and produce representative seismograms at ARPA regional array stations. The scaled signals embedded in typical background noise at the station enable an assessment of capabilities for different regional signal analysis methods at the lower thresholds. Our preliminary findings are that useful far-regional signals from small or decoupled nuclear explosions may be constrained to very limited high-frequency bands, which may limit the capabilities of some regional detection and identification techniques.