Monitoring the Comprehensive Nuclear-Test-Ban Treaty: Source Processes and Explosion Yield Estimation

425 Pages·2001·9.449 MB·English

by  Göran Ekström, Marvin Denny, John R. Murphy (auth.), Göran Ekström, Marvin Denny, John R. Murphy (eds.)

Monitoring
the Comprehensive
Nuclear-Test-Ban Treaty:
Source Processes and
Explosion Yield Estimation
Edited by
Goran Ekstrom
Marvin Denny
John R. Murphy
Springer Basel AG
Reprint from Pure and Applied Geophysics
(PAGEOPH), Volume 158 (2001), No. II
Editors:
Goran Ekstrom Marvin Denny
Harvard University Lawrence Livermore National Laboratory
Department of Earth & Planetary Sciences P.O. Box 808, MS L-205
20 Oxford Street Livermore, CA 94550-0808
Cambridge, Massachusetts 02138 USA
USA
e-mail: [e-mail]
John R. Murphy
Maxwell Technologies, Inc.
11800 Sunrise Valley Dr., Suite 1212
Reston, VA 20191
USA
e-mail: [e-mail]
A CIP catalogue record for this book is available from the Library of Congress,
Washington D.C., USA
Deutsche Bibliothek Cataloging-in-Publication Data
Monitoring the comprehensive nuclear test ban treaty. -Springer Basel AG
(Pageoph topical volumes)
Source processes and explosion yield estimation / ed. by Goran Ekstrom .... -2001
ISBN 978-3-7643-6552-3 ISBN 978-3-0348-8310-8 (eBook)
DOI 10.1007/978-3-0348-8310-8
This work is subject to copyright. AlI rights are reserved, whether the whole or part of
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obtained.
© 2001 Springer Basel AG
Originally published by Birkhăuser Verlag, Basel-Boston -Berlin 2001
Member ofthe BertelsmannSpringer Publishing Group
Printed on acid-free paper produced from chlorine-free pulp. TCF ro
987654321
Contents
1861 Preface: Monitoring the Comprehensive Nuclear-Test-Ban Treaty
B. J. Mitchell
1863 Introduction
G. Ekstrom, M. Denny, J. R. Murphy
Source Processes
1869 Effects of Rock Damage on Seismic Waves Generated by Explosions
L. R. Johnson, C. G. Sammis
1909 Wave Generation from Explosions in Rock Cavities
C. Liu, T. J. Ahrens
1951 Regional Magnitude Scaling, Transportability, and Ms:mb Discrimination at
Small Magnitudes
H. J. Patton
2017 Shallow Velocity Structure at the Shagan River Test Site in Kazakhstan
J. L. Bonner, D. C. Pearson, W. S. Phillips, S. R. Taylor
2041 The Kirovskiy Explosion of September 29, 1996: Example of a CTB Event
Notification for a Routine Mining Blast
D. R. Baumgardt, W. Leith
2059 Source Directivity, Signal Decorre1ation, Spectral Modulation and Analysis
of Spatio-temporal Patterns of Multiple Explosions
Z. A. Der, D. R. Baumgardt
2077 Seismic Source Characteristics of Soviet Peaceful Nuclear Explosions
J. R. Murphy, I. O. Kitov, B. W. Barker, D. D. Sultanov
Explosion Yield Estimation
2105 Seismic Source Characteristics of Nuclear Explosions in Water-filled Cavities
J. R. Murphy, D. D. Sultanov, N. Rimer, B. W. Barker
2123 Application of Network-averaged Teleseismic P-wave Spectra to Seismic
Yield Estimation of Underground Nuclear Explosions
J. R. Murphy, B. W. Barker
2173 Effects of Source RDP Models and Near-source Propagation: Implication for
Seismic Yield Estimation
C. K. Saikia, D. V. Heimberger, R. J. Stead, B. B. Woods
2217 Yield Estimation for Semipalatinsk Underground Nuclear Explosions Using
Seismic Surface-wave Observations at Near-regional Distances
V. V. Adushkin
2227 Yield Estimation from Surface-wave Amplitudes
J. L. Stevens, J. R. Murphy
2253 Teleseismic Lg of Semipalatinsk and Novaya Zemlya Nuclear Explosions
Recorded by the GRF (GraJenberg) Array: Comparison with Regional Lg
(BRV) and their Potential for Accurate Yield Estimation
J. Schlittenhardt
2275 Classical and Bayesian Seismic Yield Estimation: The 1998 Indian and
Pakistani Tests
R. H. Shumway
© Birkhiiuser Verlag, Basel, 2001
Pure appl. geophys. 158 (2001) 1861-1862 I
0033-4553/01/111861-02 $ 1.50 + 0.20/0 Pure and Applied Geophysics
Monitoring the Comprehensive Nuc1ear-Test-Ban Treaty
Preface
The first nuclear bomb was detonated in 1945, thus ushering in the nuclear age. A few
political leaders quickly saw a need to limit nuclear weapons through international
cooperation and first proposals to do so were made later that same year. The issue of
nuclear testing, however, was not formally addressed until 1958 when the United
States, the United Kingdom, and the Soviet Union, initiated talks intended to
establish a total ban on that testing (a Comprehensive Test-Ban Treaty or CTBT).
Those talks ended unsuccessfully, ostensibly because the participants could not agree
on the issue of on-site verification.
Less comprehensive treaties did, however, place constraints on nuclear testing.
The United States, the United Kingdom, and the Soviet Union, in 1963, negotiated
the Limited Test-Ban Treaty (LTBT) which prohibited nuclear explosions in the
atmosphere, outer space and under water. The Threshold Test-Ban Treaty (TTBT),
signed by the United States and the Soviet Union in 1974, limited the size, or yield, of
explosions permitted in nuclear tests to 150 kilotons.
Seismological observations played an important role in monitoring compliance
with those treaties. Many of the world's seismologists set aside other research
projects and contributed to that effort. They devised new techniques and made
important discoveries about the earth's properties that have enhanced our ability to
detect nuclear events, to determine their yield, and to distinguish them from
earthquakes. Seismologists are rightfully proud of their success in developing
methods for monitoring compliance with the LTBT and TTBT.
Although seismologists have also worked for many years on research related to
CTBT monitoring, events of recent years have caused them to redouble their efforts
in that area. Between 1992 and 1996 Russia, France and the United States all placed
moratoria on their nuclear testing, though France did carry out a few tests at the end
of that period. In addition, the United States decided to use means other than testing
to ensure the safety and reliability of its nuclear arsenal, and all three countries,
joined by the United Kingdom, agreed to continue moratoria as long as no other
country tested. Those developments, as well as diplomatic efforts by many nations,
led to the renewal of multilateral talks on a CTBT that began in January 1994. The
talks led to the Comprehensive Nuclear-Test-Ban Treaty. It was adopted by the
United Nations General Assembly on 10 September 1996 and has since been signed
1862 Preface 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.
Major research issues that have emerged for monitoring the CTBT are the precise
location of events, and discrimination between nuclear explosions, earthquakes, and
chemical explosions, even when those events are relatively small. These issues further
require that we understand how seismic waves propagate in the solid earth, the
oceans and atmosphere, especially in regions that are structurally complex, where
waves undergo scattering and, perhaps, a high degree of absorption. In addition, we
must understand how processes occurring at the sources of explosions and
earthquakes manifest themselves in recordings of ground motion.
Monitoring a CTBT has required, and will continue to require, the best efforts of
some of the world's best seismologists. They, with few exceptions, believe that
methods and facilities that are currently in place will provide an effective means for
monitoring a CTBT. Moreover, they expect that continuing improvements in those
methods and facilities will make verification even more effective in the future. This
topical series on several aspects of CTBT monitoring is intended to inform readers of
the breadth of the CTBT research program, and of the significant progress that has
been made toward effectively monitoring compliance with the CTBT.
The following set of papers, edited by Drs. Gorii.n Ekstrm, Marvin Denny and
John Murphy, presents research results on Source Processes and Explosion Yield
Estimation that are applicable for monitoring a CTBT. It is the fifth of eight topics
addressed by this important series on Monitoring the Comprehensive Nuclear-Test-Ban
Treaty. Previously published topics are Source Location, Hydroacoustics, Regional
Wave Propagation and Crustal Structure, and Surface Waves. Topics to appear in
ensuing issues are Source Discrimination, Data Processing, and Infrasound.
Brian J. Mitchell
Saint Louis University
Series Editor
© Birkhliuser Verlag, Basel, 2001
Pure appl. geophys. 158 (2001) 1863-1865
I
Pure and Applied Geophysics
0033-4553/01/111863-03 $ 1.50 + 0.20/0
Introduction
GORAN EKSTROMl, MARVIN DENNY2 and JOHN R. MuRPHy3
An important goal for nuclear testing monitoring research is the development of an
understanding of the processes that make up the explosion, and how these processes
give rise to seismic and other signals that can be used to characterize the explosions
and differentiate them from natural seismic events. The current compilation of eight
papers on Source Processes and six papers on Explosion Yield Estimation in the
context of nuclear test monitoring addresses a variety of issues related to the general
topic of seismic source characterization, and provides a good sampling of current
research activities in this area.
Research in the area of Source Processes is conducted in many different ways, for
example through theoretical modeling, laboratory experiments, and analysis of actual
nuclear explosions and tests. Related to this goal, and crucial for discrimination, is an
understanding of how non-nuclear explosions are different from nuclear tests. A
significant effort has consequently also been devoted to the study of conventional
large explosions such as those conducted in mines. The papers on Source Processes in
this volume address a number of these issues. The first contribution, by Johnson and
Sammis, discusses the generation of shear waves by explosions. A model of the growth
of pre-existing cracks is proposed as a likely source of shear-wave generation and is
described quantitatively as an increase in rock damage. The paper by Liu and Ahrens
describes experimental results of measuring P- and S-wave generation for explosions
in a cavity in the laboratory. In the paper by Patton, the thorny issues of magnitude
scaling and transportability between different geophysical regions are taken up in an
extensive review of Ms, mb(Pn), mb(Lg), Mw and Mo. The relationships between
these quantities are developed and biases between regions are tested as well. In the
contribution by Bonner et aI., the structure at the former Soviet test site in
Kazakhstan is interpreted from close-in data acquired during the depth-of-burial
1 Harvard University, Department of Earth & Planetary Sciences, 20 Oxford Street, Cambridge,
Massuchusetts 02138, USA. E-mail: [e-mail]. edu
2 Lawrence Livermore National Laboratory, P.O. Box 808, MS L-205 Livermore, California 94550-
0808, USA. E-mail: [e-mail]
Maxwell Technologies, Inc., 11800 Sunrise Valley Dr., Suite 1212, Reston, VA 20191, USA. E-mail:
3
[e-mail]
1864 Introduction Pure appl. geophys.,
experiment conducted by the Defense Threat Reduction Agency in 1997 and 1998.
In the paper by Baumgardt and Leith, the seismological data from a large, routine
mining blast is studied from the point of view of seismological discrimination. The
contribution of Der and Baumgardt addresses particular aspects of source charac
teristics of multiple explosions observed in seismic data, such as signal decorrelation
and spectral modulation. The source characteristics of numerous peaceful nuclear
explosions in the former Soviet Union are determined and discussed in the
contribution by Murphy, Kitov, Barker and Sultanov. In the final contribution,
Murphy, Sultanov, Rimer and Barker discuss the source characteristics of some
unique nuclear explosion tests conducted in water-filled cavities.
Seismic estimation of the yields of underground nuclear explosions has a long and
controversial history. Uncertainties associated with the determination of seismic
coupling efficiency as a function of source medium and depth of burial, and with the
estimation of the effects due to differences in seismic propagation path characteristics
from the various test areas of interest have made it difficult to formulate routine,
quantitative inversion procedures of sufficient accuracy to support stringent treaty
monitoring requirements. These uncertainties led to significant international political
problems related to verification of the 1974 Threshold Test-Ban Treaty. Although
explosion yield estimation is not an explicit element of the CTBT, it underlies all
assessments of monitoring capability and, therefore, continues to be a subject of
research interest. The six papers treating Explosion Yield Estimation included in this
volume address a number of different aspects of this complex problem.
The first contribution, by Murphy and Barker, presents a summary of the
development of a set of procedures for estimating network-averaged teleseismic
P-wave spectra for underground nuclear explosions and for analytically inverting
these spectra to obtain estimates of explosion yield. The effectiveness of these
procedures is then illustrated through applications to seismic data recorded from
explosions at various Soviet, French and Chinese nuclear test sites. The effects of
different approximate source models and near-source propagation on seismic yield
estimation capability are addressed in a paper by Saikia, Heimberger, Stead and
Woods. In this contribution they review some of the issues involved in the
application of Nevada Test Site scaling laws to other test sites and summarize some
of the results of their deterministic modeling analyses of seismic data recorded from a
wide range of nuclear tests. The use of surface wave data in the estimation of
explosion yield is addressed in papers by Adushkin and by Stevens and Murphy. The
Adushkin paper describes the development of a statistical procedure for estimating
explosion yields based on the peak amplitudes of short-period surface waves
recorded at near-regional distances, and documents the results of applying this
algorithm to a large sample of Semipalatinsk explosions. The contribution by Stevens
and Murphy focuses on long-period surface waves and addresses the issues of how
complications associated with tectonic strain release and source region geometry can
affect the accuracy of yield estimates inferred from such data. The relationship
Vol. 158,2001 Introduction 1865
between yield estimates based on regional and teleseismic Lg observations is
investigated in a paper by Schlittenhardt in which he compares results obtained using
Lg data recorded at the Borovoye station in Kazakhstan with those obtain using
corresponding Lg data recorded at the Grafenberg array in Germany. In the final
contribution, Shumway analyzes some of the statistical issues associated with
estimating explosion yields using classical and Bayesian methods, and illustrates his
derived methodology through applications to the estimation of the yields of the
recent underground nuclear tests conducted by India and Pakistan.