| Integrated Study of Seismic and Infrasonic Signals From Sources in Southern Siberia, Eastern Kazakhstan and Western China |
OCT 2004 |
68 pages |
| Authors:
Paul G. Richards; Won-Young Kim; Mike Hagerty; Vitaly Khalturin; Tatyana G. Rautian; LAMONT GEOLOGICAL OBSERVATORY PALISADESNY
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 | Our Final Report has two parts. The first part is a draft of a paper, submitted for publication, entitled "A study of small magnitude seismic events during 1961-1989 on and near the Semipalatinsk Test Site, Kazakhstan." In this paper, we have estimated origin time and assigned magnitude for 31 previously undocumented underground nuclear tests and for 19 of these 31 have obtained locations based on seismic signals. The second part ... |
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| Seismic Source and Structure in Iran from Joint Seismic Program Array Data |
25 FEB 98 |
54 pages |
| Authors:
Won-Young Kim; V. Aharonian; A. L. Lerner-Lam; Paul G. Richards; LAMONT-DOHERTY EARTH OBSERVATORY PALISADES NY
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| Our Final Report consists of the paper titled "Discrimination of Earthquakes and Explosions in Southern Russia using Regional High-Frequency Three-Component Data from the IRIS/JSP Caucasus Network." In this paper, we analyzed high-frequency regional records from small earthquakes (magnitude <4.5) , and comparable magnitude chemical explosions to find a reliable seismic discriminant in southern Russia near Kislovodsk. The digital, three-component seismograms recorded during 1992 by the Caucasus Network operated by Lamont- ... |
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| Seismic Sources in China and Korea |
FEB 1998 |
71 pages |
| Authors:
Paul G. Richards; Won-Yong Kim; LAMONT-DOHERTY EARTH OBSERVATORY PALISADES NY
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| This final report is in four parts, consisting of: (1) a five-page summary of Ph. D. thesis of Jinghua Shi entitled "Quantification of Earthquakes based on Improved Estimates of Energy using Regional Waves"; (2) an application of methods developed by this thesis, to estimate the spatial variability of seismic wave attenuation in Western China; (3) a description of an unusual swarm of seismic activity in Western China; and (4) a ... |
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| Evaluation of Chemical Explosions and Methods of Discrimination for Practical Seismic Monitoring of a CTBT |
DEC 1997 |
56 pages |
| Authors:
Vitaly I. Khalturin; Tatyana G. Rautian; Paul G. Richards; Won-Young Kim; LAMONT-DOHERTY EARTH OBSERVATORY PALISADES NY
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| Our Final Report is in three parts. Part one is a stand-alone paper, submitted for publication, entitled "The Seismic Signal Strength of Chemical Explosions." In this paper, we have compared the seismic magnitude of a wide variety of chemical explosions to the magnitude expected for explosions set off in hard rock under conditions most favorable for generating strong seismic signals. We define the deficit of ... |
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| Evaluation of Chemical Explosions and Methods of Discrimination for Practical Seismic Monitoring of a CTBT |
JUN 96 |
167 pages |
| Authors:
Vitaly I. Khalturin; Tatyana G. Rautian; Paul G. Richards; Won-Young Kim; LAMONT-DOHERTY EARTH OBSERVATORY PALISADES NY
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| Following a general introduction, our first annual technical report is in two parts. The first part, is an overall description of the data that we have acquired so far. We briefly characterize the status of our data collection efforts for twenty four separate areas of the former Soviet Union. For those areas for which we have significant data, we give Tables and Figures characterizing our data. The second part, prepared ... |
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| Characterization of Seismic Source and Path in Central Eurasia Using Digital Seismograms from Borovoye Observatory, Northern Kazakhstan |
04 FEB 96 |
76 pages |
| Authors:
Won-Young Kim; Paul G. Richards; LAMONT-DOHERTY EARTH OBSERVATORY PALISADES NY
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| This report is in three sections: (1) Decribes RMS Lg measurement for five Chinese nuclear explosions at Lop Nor recorded digitally at Borovoye, Kazakhstan (station BRVK). The regression shos scatter only a 0.045 magnitude units against ISC mb(P). (2) Summarizes a new method to determine the response of digital seismographs from their transient calibration pulses by iterative inverse technique. The method is use to derive complete instrument responses for STsR-TSG ... |
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| Characterization of Seismic Source and Path in Central Eurasia Using Digital Seismograms from Borovoye Observatory, Northern Kazakhstan |
04 FEB 96 |
76 pages |
| Authors:
Won-Young Kim; Paul G. Richards; TRUSTEES OF COLUMBIA UNIV NEW YORK
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| This final report is in three sections: (1) Describes RMS Lg measurement for five Chinese nuclear explosions at Lop Nor recorded digitally at Borovoye, Kazakhstan (station BRVK). The regression shows scatter only a 0.045 magnitude units against ISC mb(P). (2) Summarizes a new method to determine the response of digital seismographs from their transient calibration pulses by iterative inverse technique. The method is use to derive complete instrument responses for ... |
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| RMS Lg Studies of Underground Nuclear Explosions in the U.S.S.R. and the U.S |
19 AUG 93 |
123 pages |
| Authors:
Paul G. Richards; W. -y. Kim; G. Ekstrom; LAMONT-DOHERTY EARTH OBSERVATORY PALISADES NY
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| This final report is in six sections. Section one describes a new method for interpreting radiation patterns of surface waves from underground nuclear explosions at the Balapan Test Site, East Kazakhstan. We add information from body waves and RMS Lg, to conclude that strike directions of inferred faulting lie in the range 90 deg to 120 deg. This section has an Appendix. Section two describes a successful method, based on ... |
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| Preliminary Assessment of Newly Available Digital Seismic Data from Kazakhstan |
21 SEP 91 |
34 pages |
| Authors:
Paul G. Richards; Won-Young Kim; COLUMBIA UNIV NEW YORK
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| This study describes the salient characteristics of examples of digital seismic data recorded at the Borovoye Geophysical Observatory, Kazakhstan. The data resulted from a request made in 1990 and contains three- component recordings on several different types of instruments for 30 nuclear explosions and 10 earthquakes going back to 1969. Much of the data is an excellent quality, though at present the precision with which instrument responses are measured is ... |
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| Report of a Visit to the Borovoye Geophysical Observatory (Seismic Station BRV) in Kazakhstan |
18 SEP 91 |
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| Authors:
Paul G. Richards; Goeran Ekstroem; COLUMBIA UNIV NEW YORK
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 | During summer, 1991, the authors visited the Borovoye Geophysical Observatory (BRV) in Northern Kazakhstan. At this site, seismic data have been recorded digitally since 1966. There is an archive (about 70 Gbytes) of both explosion and earthquake data. We describe the history of this station, the characteristics of seismic data channels (about 50) now routinely recorded, some of the routine analysis conducted at BRV, and the archive. It is possible ... |
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| Fundamental Studies of Seismic Body Wave Attenuation |
31 MAY 90 |
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| Authors:
Paul G. Richards; LAMONT-DOHERTY GEOLOGICAL OBSERVATORY PALISADES NY
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| This contract was for work that had two principal parts . First, a study of the properties of seismic waves P sub n and S sub n. Second, a more general study of effects due to scattering, of seismic wave propagation in heterogeneous media. The completed work resulted in six publications in reviewed journals, plus three publications in non-reviewed journals and books. Keywords: Teleseismic wave propagation; Numerical models. (edc) ... |
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| The Stability of RMS Lg Measurements and their Potential for Accurate Estimation of the Yields of Soviet Underground Nuclear Explosions |
28 FEB 90 |
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| Authors:
Roger A. Hansen; Forde Ringdal; Paul G. Richards; ROYAL NORWEGIAN COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH KJELLER
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| Data on underground nuclear explosions have recently become available from modern digital seismic stations installed within the Soviet Union and China. Observations of root mean square Lg-wave signals for Soviet underground nuclear explosions at the Shagan River test site in East Kazakhstan show that the relative amplitudes of the RMS signals at stations in Norway, the U.S.S.R. and China, are very similar for different explosions, the standard deviation of only ... |
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| Regional Network: Seismicity of Asia: and Frequency-Dependent Q |
15 FEB 87 |
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| Authors:
David W. Simpson; Paul G. Richards; Arthur Lerner-Lam; COLUMBIA UNIV NEW YORK
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| A method is developed for the computation of body-wave synthetics which is suitable to a medium having smooth variation with depth and anelasticity having arbitrary variation with frequency. The method is applied to an anelastic earth model where Q is assumed to follow a power-law frequency dependence. The outcome is a pulse shape with properties quite different from what might be expected if the familiar constant-Q pulse shapes are surveyed. ... |
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| Elementary Solutions to Lamb's Problem for a Point Source and Their Relevance to Three-Dimensional Studies of Spontaneous Crack Propagation |
AUG 1979 |
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| Authors:
Paul G. Richards; CALIFORNIA INST OF TECH PASADENA DIV OF GEOLOGICAL AND PLANETARY SCIENCES
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| Certain exact solutions to Lamb's problem (the transient response of an elastic half-space to a force applied at a point) involve the computation merely of three square roots, and about ten arithmetic operations (+, -, x, and division). They arise when both source and receiver lie on the free surface. It is just these solutions which are needed in a method due to Hamano for obtaining the slip function (displacement ... |
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| Theory and Calculation for the Displacements and Stresses at an Earthquake source. |
01 JUN 1976 |
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| Authors:
Paul G. Richards; LAMONT-DOHERTY GEOLOGICAL OBSERVATORY PALISADES N Y
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| Contents: First strong motion records from a Central or Eastern United States earthquake; Source properties of a Blue Mountain Lake earthquake; Comparison of strong ground motion from several dislocation models; The dynamic field of a growing plane elliptical shear crack; Motions near a shallow rupturing fault: evaluation of effects due to the free surface; and List of publications. |
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| Theory and Calculation for Displacements and Stresses at an Earthquake Source. |
30 OCT 1974 |
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| Authors:
Paul G. Richards; LAMONT-DOHERTY GEOLOGICAL OBSERVATORY PALISADES N Y
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| The progress report describes the near-field motions of an earthquake source model which is governed by simple physical constraints in terms of dynamic friction on a fault plane. It also describes a computer program which will calculate the displacements radiated (into the near, intermediate, and far field) by any of a wide variety of earthquake fault motions. Several applications of the program are described. |
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| Theory and Calculation for Displacements and Stresses at an Earthquake Source. |
30 APR 1974 |
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| Authors:
Paul G. Richards; LAMONT-DOHERTY GEOLOGICAL OBSERVATORY PALISADES N Y
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| The progress report describes the method of calculation of ground motions near an earthquake source, and outlines the research which has led to ten-fold improvements over the previous computational methods. It is shown that surface waves are likely to contribute strongly to near-source ground-motions. A scalar problem is described, in terms of which one may better appreciate the essential difficulties of relating dislocation and traction on a rupturing fault surface. ... |
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Reports by Author
