Spectral characteristics of regional phases recorded at Noress

1988 ◽  
Vol 78 (2) ◽  
pp. 708-725
Author(s):  
Anne Suteau-Henson ◽  
Thomas C. Bache
Keyword(s):  
Soviet Union ◽  
Nuclear Explosion ◽  
Spectral Characteristics ◽  
Low Frequency ◽  
Spectral Ratio ◽  
Spectral Ratios ◽  
Data Set ◽  
Nuclear Explosions ◽  
The Soviet Union ◽  
Mine Blasts

Abstract The spectral characteristics of Pn and Lg are studied for regional events recorded at the NORESS array in Norway. The emphasis is on the potential value of spectral ratios for identifying events as earthquake, chemical explosions, and nuclear explosions. The events studied include a suite of explosions from the Titania Mine in southwest Norway, a suite of events of unknown source type from a site offshore about 90 km from this mine, suites of explosions from several mines in the Soviet Union about 1000 km from NORESS, events from several locations along the 90° azimuth from NORESS, an apparent earthquake in the North Atlantic, and a nuclear explosion (PNE) at a range of 1560 km. The event identification issues addressed are as follows: (1) Can earthquakes and explosions be identified based on the ratio of high- and low-frequency energy in their signal spectra? (2) Do spectral ratios separate mine blasts from earthquakes for all source areas? (3) Will spectral ratio discriminants be effective for identifying decoupled underground nuclear explosions? We conclude that spectral ratios can sometimes separate events. An example is separation of the Titania mine blasts from the events at the nearby offshore locations, although we cannot be sure how much this is due to path differences. However, in general, spectral ratios vary as much within classes of events as they do among different classes. The PNE in our data set allows the simulation of spectra from a decoupled nuclear explosion by simply applying the frequency-dependent decoupling factor to the observed Pn spectrum for this event. After applying a distance correction, the spectrum for this simulated decoupled nuclear explosion is similar to those for the Soviet Union mine blasts in our data set.

Near-source effects on regional seismograms: An analysis of the NTS explosions PERA and QUESO

1991 ◽  
Vol 81 (6) ◽  
pp. 2371-2394
Author(s):  
Steven R. Taylor ◽  
John T. Rambo ◽  
Robert P. Swift
Keyword(s):  
Shock Wave ◽  
High Frequency ◽  
Spectral Characteristics ◽  
Low Frequency ◽  
Spectral Ratio ◽  
Corner Frequency ◽  
Burial Depth ◽  
Wave System ◽  
Spectral Ratios ◽  
Remarkable Similarity

Abstract A comparative analysis of two closely spaced Nevada Test Site explosions, PERA and QUESO, is made to study the effects of near-source phenomena on regional-wave excitation. Although the two explosions were of similar size, burial depth, and only separated by 4 km, the 1 to 2 and 6 to 8 Hz regional-wave spectral ratio for QUESO is anomalously low (a factor of 10 smaller than that of PERA). Examination of the regional and close-in spectra for each event shows a remarkable similarity and suggests that QUESO has less low-frequency and more high-frequency energy than PERA. These observations may be caused by a 564 m3, funnel-shaped region filled with unconsolidated sand and a possible void directly above the QUESO detonation point. Close-in observations suggest that this region may have partially decoupled the up-going energy from QUESO, resulting in a reduction of the low-frequency energy. The high-frequency enhancement for QUESO may be due to the rapid loss of energy to nonlinear effects such as greater pore collapse and fracturing in the anomalous region. This resulted in the radiation of more impulsive, shorter-duration waveforms producing a higher corner frequency and less-rapid high-frequency spectral decay for QUESO. For PERA, the loss of energy to a two-wave system occurred more slowly and over a larger volume, resulting in a broader source pulse typical of explosions in porous materials. Comparison of shock radius versus time data suggests that the shock wave was strongly affected in the anomalous zone a few meters above the QUESO device. One-dimensional finite-difference calculations with and without a partial decoupling region within 8 m of the device are consistent with the observations. Although spallation was reduced for QUESO, simulations using a finite spall model indicate that the spall spectral peak should be centered at about 3 to 7 Hz and probably did not significantly contribute to the reduced spectral ratio. The remarkable similarity of the PERA/QUESO spectral ratios taken at distances of 90 m and 400 km suggests that the spectral characteristics of explosions are established in close proximity to the source. Although depth-dependent effects of attenuation acting at small strains may enhance the differences in spectral ratios between NTS explosions and western U.S. earthquakes, these effects are probably secondary to the high-pressure, high strain-rate dynamic material response to the radiated explosion shock wave. These observations point out the importance of up-going energy on the generation of regional phases from explosions. Because of reduced overburden pressures above the detonation point, large nonlinear deformations predominate in this region and appear to affect all of the signals except perhaps the very initial part of the Pn waveform.

scholarly journals On the use of the coda of seismic noise autocorrelations to compute H/V spectral ratios

2019 ◽  
Vol 220 (3) ◽  
pp. 1956-1964 ◽  
Author(s):  
F N Tchawe ◽  
B Froment ◽  
M Campillo ◽  
L Margerin
Keyword(s):  
Ambient Noise ◽  
Sedimentary Basin ◽  
Temporal Stability ◽  
Spectral Ratio ◽  
Spectral Ratios ◽  
Data Set ◽  
Underlying Assumption ◽  
Seismic Ambient Noise ◽  
Physical Information ◽  
Local Medium

SUMMARY The horizontal to vertical spectral ratio (HVSR) of seismic ambient noise has been proven to be a fast and efficient method for characterizing the 1-D resonance frequency of the local subsurface in a practical framework. Over the last decades, theories have been developed in order to extend the exploitation of HVSR beside the frequency of its first peak, notably the diffuse field assumption (DFA) which links the HVSR to the Green’s function of the local medium assuming the diffuseness of the seismic ambient noise wavefield. However, the underlying assumption of the seismic ambient noise being a diffuse, equipartitioned field may not be satisfied under certain circumstances. In order to exploit the contribution of scattering in forging diffuse wave fields, we leverage the advantages of coda waves and present a novel procedure for computing the HVSR, using the coda part of ambient noise correlations. We applied this technique to data gathered at the plio-quaternary sedimentary basin of Argostoli, Greece. Results on this data set show the potential of the method to improve the temporal stability of the HVSR measurements compared to the classical computation, and the fit with the theoretical HVSR curve derived from the DFA theory. These results suggest that this procedure could help in extracting physical information from the HVSR and thus could lead to an extended use of these measurements to characterize the mechanical properties of the medium.

scholarly journals The Refined USSR Peaceful Nuclear Explosions Database for Borovoye Geophysical Observatory

Data ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 56
Author(s):  
Nepeina ◽  
An
Keyword(s):  
Soviet Union ◽  
Source Parameters ◽  
Integrated Approach ◽  
Industrial Applications ◽  
Columbia University ◽  
P Waves ◽  
Geophysical Observatory ◽  
Nuclear Explosions ◽  
The Soviet Union ◽  
The Republic

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.

scholarly journals Discrimination of teleseismic events in Central Asia with a local network of short period stations

1994 ◽  
Vol 37 (3) ◽  
Author(s):  
T. Tiira ◽  
M. Tarvainen
Keyword(s):  
Spectral Ratio ◽  
Difficult Problem ◽  
P Wave ◽  
Local Network ◽  
Separation Function ◽  
Data Set ◽  
Underground Nuclear Explosions ◽  
Nuclear Explosions ◽  
Discrimination Capability ◽  
Short Period

The difficult problem of distinguishing underground nuclear explosions from earthquakes at teleseismie distances was approached using short period seismic data from 6 stations in South and Central Finland. The events were nuclear tests mostly from the Semipalatinsk and Lop Nor test sites and earthquakes from adjacent areas. The magnitude range of the events was from 4.1 to 6.6. The features of the two classes of events were examined by computing spectral ratio, third moment of frequency (TMF) and complexity from P wave signals. The spectral discrimination parameters were extracted from spectra computed in 5 different ways in order to obtain all possible information even from weak events. The standard FFT spectra were computed from. raw data, after noise adaption and data adaption, from correlograms and using combinations of adaption and correlation: methods. This was done to employ not only the spectral differences of the events but also the temporal variation of energy and lack of it as a function of frequency. The optimum frequeney windows for spectral ratio and TMF were defined using stacked spectra of about 10 events from both classes. No single discriminant could classify all the events. Their performance varied significanfly for different stations, but on average the spectral discriminants had slightly higher discrimination capability than complexity. The distributions of all discriminants were studied and a group separation function was formed using an optimum set of discriminants. Instead of discriminant values their relative positions in the corresponding distributions of nuelear tests and earthquakes were used as inputs to the function. A weight for each discriminant was derived from the amount of overlap in the distributions of earthquakes and nuelear tests. All 75 events in the data set were correctly classified with the method. The testing was performed with a jack knife method to create an independent test data base

scholarly journals Entrepreneurial University Perspective: Tracking Labor Force Capacity to Support Industrialization Processes in the Emerging Markets, Evidence from Kazakhstan Data

2017 ◽  
Vol 6 (2) ◽  
pp. 5-11
Author(s):  
Dilara Orynbassarova
Keyword(s):  
Labor Market ◽  
Soviet Union ◽  
Emerging Markets ◽  
Labor Force ◽  
Low Frequency ◽  
The Soviet Union ◽  
Economic Production ◽  
Central Asian ◽  
Outflow Rate ◽  
Main Engine

Industrialisation is considered as main engine of growth in economic development of the most emerging markets. This is especially true for Central Asian transitional countries as Kazakhstan, which obtained independence from the Soviet Union in 1991. For enhancing country’s competitiveness potential, Kazakhstan National Program for 2010-2014 aimed to accelerate industrial-innovative development of the country. While many papers published about the importance of industrialization activities in Kazakhstan, few have focused on examining the current capacity of labor market to meet the industry demand. Main aim of this paper was to investigate if current manpower is adequate to maintain the planned rate of growth in the country. Higher level of economic production led to higher demand of engineering labor force. High demand with low frequency supply created an imbalance in the labor market that resulted what we see as shortage of technically skilled labor. Low frequency of supply is influenced by such factors as high engineers’ outflow rate, low students enrolment and graduation rates, and lack of practical skills of the graduates hired. An erratum to this article has been published as https://doi.org/10.5195/emaj.2017.132. 

The Durability of Client Regimes

2020 ◽  
Vol 72 (3) ◽  
pp. 411-447
Author(s):  
Adam E. Casey
Keyword(s):  
Soviet Union ◽  
Original Data ◽  
The United States ◽  
Data Set ◽  
The United Kingdom ◽  
The Soviet Union ◽  
The Us ◽  
Regime Survival ◽  
The Relationship ◽  
Coups D'etat

ABSTRACTConventional wisdom holds that great power patrons prop up client dictatorships. But this is generally assumed rather than systematically analyzed. This article provides the first comprehensive analysis of the relationship between foreign sponsorship and authoritarian regime survival, using an original data set of all autocratic client regimes in the postwar period. The results demonstrate that patronage from Western powers—the United States, France, and the United Kingdom—is not associated with client regime survival. Rather, it’s only Soviet sponsorship that reduced the risk of regime collapse. The author explains this variation by considering the effects of foreign sponsorship on the likelihood of military coups d’état. He argues that the Soviet Union directly aided its clients by imposing a series of highly effective coup prevention strategies. By contrast, the US and its allies didn’t provide such aid, leaving regimes vulnerable to military overthrow.

Great Powers and Atomic Bombs are “Paper Tigers”

1965 ◽  
Vol 23 ◽  
pp. 55-63 ◽  
Author(s):  
Ralph L. Powell
Keyword(s):  
United States ◽  
Great Britain ◽  
Soviet Union ◽  
Nuclear Weapons ◽  
Nuclear Explosion ◽  
The United States ◽  
Great Powers ◽  
Air Power ◽  
The Soviet Union ◽  
Communist China

In terms of Western political science or military doctrine it seems somewhat irrational that the leaders of Communist China should refer to great powers as “paper tigers.” It appears even more illogical that they should call atomic bombs “paper tigers,” especially when they themselves place the highest priority on the development of a nuclear capability. Yet, since the first Chinese nuclear explosion on October 16, 1964, the official Communist Press has again referred to the United States, Great Britain and the “revisionists” (both Khrushchev and the present leaders of the Soviet Union) as “paper tigers.” This same metaphor has also been applied to “imperialism” and “all reactionaries,” as well as to nuclear weapons, air-power and sea-power.

Intimate Violence

2018 ◽  
Author(s):  
Jeffrey S. Kopstein ◽  
Jason Wittenberg
Keyword(s):  
Soviet Union ◽  
Scientific Explanation ◽  
Original Data ◽  
Ethnic Violence ◽  
Intimate Violence ◽  
Data Set ◽  
The Soviet Union ◽  
The Holocaust ◽  
Perpetrators And Victims ◽  
Social Scientific

Why do pogroms occur in some localities and not in others? This book address that age-old question through an examination of a particularly brutal wave of violence that occurred across hundreds of predominantly Polish and Ukrainian communities in the aftermath of the June, 1941 German invasion of the Soviet Union. Exploiting the collapse of state authority, some Poles and Ukrainians viciously attacked their Jewish neighbors. Against explanations that focus on antisemitism or alleged Jewish support for communism, Intimate Violence argues that pogroms were most likely to occur where Jews had sought national equality with Poles and Ukrainians prior to the outbreak of war. In these communities, where Jews challenged Poles’ and Ukrainians’ dreams of national dominance, local non-Jews were more likely to perpetrate violence and less likely to protect their Jewish neighbors. Intimate Violence is a novel social scientific explanation of ethnic violence and the Holocaust that combines statistical analysis of an original data set with archival research and case studies. It cuts through painful debates about relative victimhood that are driven more by metaphysical beliefs in Jewish culpability than empirical evidence of actual perpetrators and victims. In doing so it sheds new light on the roots of mass ethnic violence and the ways in which such gruesome acts might be avoided.

Centralization and Elite Circulation in a Soviet Republic

1989 ◽  
Vol 19 (1) ◽  
pp. 1-23 ◽  
Author(s):  
Michael E. Urban
Keyword(s):  
Soviet Union ◽  
Markov Process ◽  
Policy Making ◽  
Central Control ◽  
Soviet Republic ◽  
Full Data ◽  
Data Set ◽  
Markov Analysis ◽  
The Soviet Union ◽  
Systemic Model

Central control over personnel placement in the Soviet Union (the nomenklatura system) is widely regarded as the complement to the centralization of substantive policy making and implementation. Some recent studies, however, argue that the central authorities have used their appointments powers to ratify rather than alter the results of the circulation process specific to localities. In order to advance the terms of this discussion, (he present study employs a systemic model of circulation. Here, circulation is regarded as a Markov process involving the movement of vacancies across a stratified hierarchy of 2,034 positions in the Belorussian Republic, and allunion jobs occupied by Belorussian politicans, over the period 1966–86. The model's predictions are reasonably accurate for the full data set but fit the data especially well when all-union positions are excluded, indicating a marginal centralizing influence on elite circulation that results more from the interaction between national and republic personnel systems than from centrally co-ordinated cadres policies in either Moscow or Minsk. Three auxiliary tests also support the conclusions derived from the Markov analysis.

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