bluuebunny/crossref_metadata_2025 huggingface dataset:
FEATURES OF ETHNOCULTURAL ACTIVITY OF THE UKRAINIAN DIASPORA IN RUSSIA IN THE AGE OF PUTINISM
Authors: Obushnyi Mykola
Published: September 2021

The article is devoted to the analysis of the Ukrainian diaspora organizations ethnocultural activity peculiarities in the Russian Federation (RF), the beginning of which is connected with the collapse of the Soviet Union and the proclamation of Ukraine‟s independence (1991). The author connects their appearance with the growth of national consciousness, which was based on the idea of Ukraine‟s independence. This idea has always been perceived extremely negatively and cautiously by the ruling class of Russia, as well as by a significant number of Russians, at all times when Ukrainians were under the imperial roof.
Even in the conditions of the total crisis at the turn of the 1980s and 1990s, when the systemic disintegration of the USSR began, the Communist Party leadership constantly kept the "Ukrainian question" in view. This is confirmed, in particular, by the termination in 1989 of the magazine "Ukrainian Question", the publication of which was organized by the Moscow branch of the "Ukrainian Helsinki Union".
A similar fate befell a number of other Ukrainian communities already in modern Russia. Among them are the two largest all-Russian diaspora organizations of Ukrainians in Russia: the Union of Ukrainians of Russia (ESD) and the Federal National-Cultural Autonomy "Ukrainians of Russia" (FNKAUR). The analysis below shows that their activities were carried out in accordance with Russian legislation, in particular the Federal Law of Russia "On National and Cultural Autonomy" and was aimed at organizing and conducting ethnocultural work among Ukrainians. However, Putin's leadership found "evidence of political activity" from both ESD and FNKAUR and banned their activities by court order.
In fact, the main reasons for the author's cessation are the independence policy of modern Ukraine and the leaders of Ukrainian diasporas, their "disobedience" to pursue Russia's state imperial policy among Ukrainians, and their unwillingness to ignore the ethnocultural needs of Ukrainians.
Currently, there is no all-Russian organization of Ukrainians in Russia. Activists of the Ukrainian diaspora have repeatedly, and since 2014, tried to register at least one of them, but they are constantly denied on the grounds that they will allegedly "glorify Bandera" and negatively affect Ukrainian-Russian relations. In fact, the reason is different, namely, in the traditional imperialism not only of Russia's ruling class, but also of a significant number of Russians who do not see a Russian neo-empire without Ukraine. This Russian propaganda cliché penetrated deeply not only into the consciousness of Russians, but also distorted the national consciousness of a significant number of Ukrainians in Russia, who cease to identify themselves as Ukrainians. The article emphasizes that the deidentification of our compatriots is based on persecution, harassment, contempt, not only the Kremlin authorities, but also a significant number of Russians towards Ukrainians in Russia.
IDENTITY MARKERS IN THE CONTEXT OF POLITICALLY MOTIVATED PERSECUTION OF UKRAINIANS AND CRIMEAN TATARS IN THE TEMPORARILY OCCUPIED CRIMEAN PENINSULA
Authors: Petrunok Boris
Published: September 2021

This article is dedicated to the study of identity markers in the context of politically motivated persecution by the Russian Federation in the temporarily occupied Crimean Peninsula. The occupational administration, following a set political course, basically builds a generalized „Other‟ that is being persecuted. They also create their own identity markers that further prove the longevity and legitimacy of the temporary occupation of Ukraine's territory.
Cases of human rights violations, harassment of national and religious communities in the occupied Crimea are actively documented and investigated by non-governmental human rights organizations: Crimean Human Rights Group, Crimea SOS, Regional Center for Human Rights, Crimean Tatar Resource Center and a number of others. In the article proposed a comprehensive approach to the analysis of collective identity Crimean Tatars and Ukrainian.
Author examined the main components of collective identity Crimean Tatars at the present stage. Considered the main challenges faced by the Crimean Tatar and Ukrainian community in connection with the occupation of the Crimea. Today we can talk about a specific list of elements indicating the ethnocide and linguicide agenda, political and religious persecution in the Crimean Peninsula. Furthermore, the so-called „general threat‟ is too blurry and undefined for the Russian Federation based on the gathered material throughout the years of occupation. The occupant cannot classify and define the risks that they face and that compromise the illegal occupation and attempt to annex a part of Ukrainian territory.
So, they target all the self-organized active communities that are not controlled by the occupational government. Whether these communities have an agenda, national, cultural, or religious differences is an important factor, but it is not in priority.
The Russian occupational regime understands its weakness on the temporarily occupied territory of the Crimean Peninsula, so it utilizes the logic and traditions of other authoritarian and totalitarian regimes. However, it will lead to the collapse of the dictatorship.
BELARUSIANS AND UKRAINIANS IN ANTI-SOVIET LOCAL ARMED CONFLICTS ON THE TERRITORY OF SOVIET BELARUS (1920–1930S)
Authors: Pushkin Ihar
Published: September 2021

The article is devoted to the study of anti-Soviet resistance in Belarus in the 1920s and 1930s. For the last twenty years this topic has been silenced in the official scientific publications of the Republic of Belarus. Most documents on armed anti-Soviet resistance are kept in the KGB archives, to which a researcher in the Republic of Belarus has limited access. The author analyzes the participation of the Belarusian population in anti-Soviet local armed conflicts. The vast majority of actions of the Bolshevik government brutally violated the traditional way of life, which caused outrage among the Belarusian population, which grew into armed forms of protection of property and dignity. On the basis of archival materials the activity of insurgent detachments is revealed. In the period 1919–1923, 1925–26, 1930–1931. the actions of armed peasants and intellectuals in Soviet Belarus had a clear political context.
For the purposes of the insurgent detachments, anti-Soviet units, which fought for the elimination of Soviet power, and Belarusian national units, which sought to create an independent Belarusian state, are nominated - these are the organizations “Biloruske bratstvo”, “Za Batkivshchynu”, “Zelenyy Dub”. They had a military structure, interacted with each other, enjoyed the broad support of the population. They were attended not only by Belarusians but also by Ukrainians, both of local origin and those who found themselves in Belarus. The article shows the fighting destiny of the insurgent leaders Mefodiy Karatkevich, Vasil Shevchenko, Mikhail Bakun, Fyodor Shatsko. On the part of the Soviet authorities, the main method of combating the insurgent movement was to use force. The author concludes that a fairly large part of the population of Belarus did not perceive the Soviet state as their own and interpreted the Bolshevik government as aggressive and not legitimate. The massive anti-Soviet armed resistance ended both under the influence of the transition to a new economic policy and the forced destruction of the most conscious and hardworking part of the Belarusian population.
CAN UKRAINE DEFEAT RUSSIA IN A WAR OF THE FUTURE? (Book review: Vladimir Gorbulin. How to defeat Russia in a war of the future. K.: Bright Books, 2020. 256 p. In Russian)
Authors: Grabovska Iryna
Published: September 2021

The review of Vladimir Gorbulin's book "How Russia Will Defeat in the War of the Future" analyzes the main theoretical and practical tasks set by the author before the Ukrainian state and society, aimed at overcoming such a strong and extremely dangerous enemy for independent Ukraine as Putin's Russia. Academician Gorbulin's book immediately became a bestseller in Ukraine and gained notoriety abroad. It is one of the most serious studies of the problems facing the Ukrainian state and nation today, as well as a de facto "road map" for Ukraine in the war against Russia, which can create conditions for victory and independence and freedom from the sinister aggressor - the Kremlin neo-empire.
SOSYAL BİLGİLER ÖĞRETİMİNDE SEYAHATNAMELERİN KULLANILMASI
Authors: Özensoy Ahmet Utku
Published: September 2021

Bu çalışmanın amacı, sosyal bilgiler öğretimi bağlamında seyahatnameleri incelemek ve bu seyahatnamelerin nasıl kullanılacağını ortaya koymaktır. Çalışma, nitel araştırma yöntemine göre desenlenmiştir. Bu yöntemin tarama modeli tercih edilmiştir. Araştırmada Osmanlı Devleti’nde yabancı seyyahların yazdıkları seyahatname, anı, mektup ve günlükler kullanılmıştır. Bu eserlerin her birinin adı, yazarı, yazarın uyruğu, seyahatin yapıldığı yıl(lar) ile dönemin padişahlarına yer verilmiştir. Veriler 40 seyahatnameden doküman analizi yoluyla toplanmıştır. Sosyal Bilgiler Öğretim Programı’nda (2018) seyyah ve seyahatname kavramları sadece birer defa geçmektedir. Sosyal Bilgiler 7. Sınıf Ders Kitabı’nda ise “seyyah” kavramı 29 kez, “seyahatname” kavramı 18 defa kullanıldığı görülmektedir. Diğer sınıflarda bu kavramlara yer verilmediği anlaşılmaktadır. Araştırmada 40 seyahatname, anı, mektup ve günlük hakkında bilgiler ile bunların adı, yazarı, yazarın uyruğu, seyahatin yapıldığı yıllar ve seyahatin yapıldığı dönemdeki padişah isimlerine yer verilmiştir. Bunun yanında seyahatname, anı, mektup ve günlüklerden doğrudan alıntılar yapılmış ve hangi kazanımların öğretiminde kullanılabileceği ortaya çıkarılmaya çalışılmıştır. Sosyal bilgiler ders kitaplarında seyahatnamelere 5 ve 6. Sınıf ders kitaplarında yer verilmediği, bundan dolayı bu kitaplarda da seyahatnamelere yer verilmesi gerektiği söylenebilir. Programda ve ders kitaplarında seyahatnamelere daha fazla yer verilmesi, beceri ve değer öğretiminde yararlanılması, bu konuda öğretmen, akademisyen ve yazarlara eğitim verilmesi gibi önerilerde bulunulmuştur.
The combined effects of transverse isotropy and inhomogeneity on Love waves
Authors: Thapliyal V.
Published: September 2021

abstract

The characteristic frequency equation for Love waves propagating in a finite layer overlying an anisotropic and inhomogeneous half-space is derived. This frequency equation takes into account the arbitrary variation of density, elastic parameters, and degree of anisotropy factor in the half-space. In fact, the problem of deriving the frequency equation has been reduced to finding the solution of the equation of motion subject to the appropriate boundary conditions. To illustrate the method, the author has derived the frequency equation for a generalized power law variation of density and elastic parameters with the depth, in the halfspace.

As a step toward the systematic investigation of the effects of anisotropy and inhomogeneity, the relationship between the wave number and phase and group velocities has been worked out for increasing, uniform and decreasing anisotropy factor. The pronounced effects of anisotropy have been noticed in the long-period range compared to the short-period one. The numerical analysis shows that for a given phase velocity (or group velocity), the period of propagation depends on the sign and magnitude of power of variation of the density and anisotropy factor in the half-space. For the increased positive rate of variation of the anisotropy factor, the values of phase and group velocities have been found higher whereas the reverse is found true for an increasing negative rate of variation of the anisotropy factor.
Seismic magnitudes of underground nuclear explosions
Authors: Basham P. W. , Horner R. B.
Published: September 2021

abstract

Using an Ms computational procedure that minimizes path-propagation effects, and with Ms values found to be empirically independent of test site and detonation medium among consolidated rock explosions, available yield information is employed to illustrate that the seismic scaling of explosions in realistic detonation environments produces teleseismic Rayleigh-wave displacements proportional to the 1.2-power of yield over the range from low yields to greater than three megatons. Ms values independent of network, path, and site can be employed to estimate unknown yields at uncalibrated test sites to within average errors judged to be about 20 per cent.

P-wave magnitudes, in the form of a calibrated teleseismic measure of short-period P-wave displacements, show a theoretically supported dependence of displacement on the 1.1-power of yield over the range from 6 kt to 1 mt. Studied explosions separate into two categories: the Nevada Test Site granite explosions, LONG SHOT, the Sahara February 1965 explosion and (by empirical inference) Novaya Zemlya and Eastern Kazakh explosions exhibit P-wave displacements about a factor of 3 greater than explosions of the same yield in tuff, rhyolite, and shale. P-wave magnitudes of explosions are subject to such a diversity of source, propagation, and measurement phenomena that any estimation of unknown yields without a closely controlled site and network calibration can be subject to large errors.
Observed effects of topography on ground motion
Authors: Davis Lawrence L. , West Lewis R.
Published: September 2021

abstract

Field experiments were performed to obtain data needed for studying the effects of topography on seismic motion. L-7 instruments deployed at the crest and base of Kagel Mountain and Josephine Peak, California, recorded several aftershocks of the February 9, 1971, San Fernando earthquake. L-7 instruments deployed at the crest, middle, and base of Butler Mountain near Tonopah, Nevada, recorded the seismic signal generated by the cavity collapse following the Nevada Test Site detonation, ALGODONES. Frequency-dependent amplification of the motion at the crest relative to the motion at the base was observed at all three mountains. Factors as large as 30 in the frequency domain were seen at Kagel Mountain with lesser amounts at the other two locations. The three mountains are similar in shape, but different in size. The effect of shape is not clear. The smallest mountain amplified the motion in a narrow range of periods (peaking around 0.3 to 0.5 sec), the medium-size mountain showed amplification over a slightly broader range (peaking at periods of 0.4 to 0.5 sec), whereas the largest mountain showed less amplification, but it occurred over a broader range of periods. Effects in the time domain are generally comparable to, or less than, the effects in the frequency domain. The ratios of peak amplitudes (crest to base) are usually less than the spectral ratios. It is concluded that topography plays a significant role and is an important consideration in determining the seismic motion that a particular site receives.
A note on discrepancies between local magnitude (ML) and microearthquake magnitude scales
Authors: Thatcher Wayne
Published: September 2021

abstract

A necessary correction for relating local network magnitude scales to Richter's local magnitude (ML) involves accounting for the shape of the far-field body-wave spectrum of the phases used for determining magnitude. When not corrected for, this effect causes errors of about one magnitude unit at ML ∼ 3 for some southern California earthquakes. The discrepancy should be comparable for ML > 3, but at smaller magnitudes will decrease with decreasing ML. It may be corrected for either by direct comparison of network scales with magnitudes determined from Wood-Anderson seismograms, or by spectrum measurements over a range of magnitudes. The nature of the discrepancy and the corrections required to account for it are demonstrated by an example, the aftershocks of the 1968 Borrego Mountain, California earthquake.
A portable multi-channel seismic recorder and a data processing system
Authors: Green R.
Published: September 2021

abstract

A portable seismograph utilizing a magnetic tape recorder and capable of recording both long- and short-period seismic information is described. The field system which is housed in two weatherproof steel containers is completely self-contained and incorporates both a radio and an internal clock for timing. Eight data channels can record in either AM or FM mode which allows a frequency range from dc to 200 Hz. A feature of the field system is that it incorporates a test panel that enables a check to be kept on all of the recording functions. The field system power consumption is less than 7.5 watts and two 6-volt batteries power the system for up to 12 days. The replay electronics are primarily designed to digitize the analog tapes and the process utilizes an “aspect clock” dividing system that links the recorded clock time to the digitization time.
Body waves as normal and leaking modes: Dispersion and excitation on the (+ −) sheet
Authors: Stalmach D. M. , De Bremaecker J. Cl.
Published: September 2021

abstract

Leaking modes are little influenced by the presence of a low α layer. The lattice-like structure of the phase-velocity curves occurs for a two-layer model as well as for a six-layer one. The excitation tends to be high where phase-velocity curves cross (or approach) each other. Both normally and inversely dispersed wave trains are predicted; the agreement with the observations varies from fair to good.
A variational method for love waves in nonhorizontally layered structures
Authors: Gjevik B.
Published: September 2021

abstract

A variational principle for Love waves propagating in a layer with varying thickness overlying a half-space is formulated. By an averaging procedure, the wave modulation due to gradual variation of the thickness of the upper layer is found. The case of long-period Love waves is particularly examined and the wave number and amplitude modulation both for a monochromatic wave and for a transient wave train due to an impulsive source are determined. Moreover, the travel time for a certain phase in the wave train is determined. It is found that for well-dispersed wave trains the travel time is given by the phase velocity corresponding to the mean depth of the upper layer.
Coupled torsional dynamic analysis of a multistory building
Authors: Douglas Bruce M. , Trabert Thomas E.
Published: September 2021

abstract

The coupled bending and torsional vibrations of a relatively symmetric 22-story reinforced concrete building in Reno, Nevada are studied. Analytical results are compared with observations obtained during the nuclear explosion FAULTLESS and to ambient vibration data. The fundamental periods of vibration observed during FAULTLESS were (TNS = 1.42, TEW = 1.81, TTORSION = 1.12 sec), and the calculated periods were (TNS = 2.14, TEW = 2.07, TTORSION = 1.90 sec). It was estimated that between 25 and 45 per cent of the total available nonstructural stiffness was required to explain the differences in the observed and calculated fundamental periods.

Each floor diaphragm in the system was allowed three degrees of freedom-two translations and a rotation. It was found that coupled torsional motions can influence the response of structural elements near the periphery of the structure. Strong-motion structural response calculations comparing the simultaneous use of both components of horizontal ground motion to a single component analysis showed that the simultaneous application of both components of ground motion can significantly alter the response of lateral load-carrying elements. Differences of the order of 45 per cent were observed in the frames near the ends of the structure. Also, it was shown that the overall response of tall buildings is sensitive not only to the choice of input ground motion but also to the orientation of the structure with respect to the seismic waves.
A note on the calibration of the electromagnetic seismograph
Authors: Jarosch Hans , Curtis A. R.
Published: September 2021

abstract

Explicit expressions are given for the response in the time domain of a zerocoupled seismometer-galvanometer combination for a step of acceleration as initial conditions. The results may be directly applied for computing the system parameters.
Comparison of earthquake and microtremor ground motions in El Centro, California
Authors: Udwadia F. E. , Trifunac M. D.
Published: September 2021

abstract

Strong earthquake ground shaking has been investigated by the study of 15 events recorded in El Centro, California. The strong-motion records analyzed show that no simple features (e.g., local site conditions) govern the details of local ground shaking. Any effects of local subsoil conditions at this site appear to be overshadowed by the source mechanism and the transmission path, there being no distinctly identifiable site periodicities.

Microtremor measurements have been taken in the area surrounding the strong-motion site. The objective was an investigation of possible correlations with strong ground motions and the analysis of site-response characteristics. Basic difficulties in ascertaining local site conditions through such low-amplitude ground motions are illustrated. It has been found that in this area microtremor and earthquake processes are widely different in character, there being little to no correlation between the ground's response to earthquakes and to microtremor excitations. Microtremors have been found to be nonstationary over periods of about a day or so, introducing further uncertainties into inferences from such measurements.
Stress drop and aftershocks
Authors: Gibowicz S. J.
Published: September 2021

abstract

Eighteen aftershock sequences, nine from California and nine from New Zealand, are studied. It is found that a general relationship exists between the local magnitude ML and the stress drop in the main shock. The stress drop in the main earthquake determines the principal characteristics of the aftershock sequences. A low stress drop leads to a low value of the coefficient b, high magnitude of the largest aftershock, and short duration, and conversely. A sequence is arbitrarily considered to be over when the rate of aftershock occurrence falls to a value of one shock per day. The duration depends on the area of fault surface and the stress drop in the main shock. For an average stress drop, the coefficient b has a value of 0.8 to 0.9, and the difference in magnitude between the main shock and the largest aftershock is 1.2, a relation often called Båth's law.
The calculation of horizontal accelerations from seismoscope records
Authors: Scott Ronald F.
Published: September 2021

abstract

The seismoscope is a simple instrument designed originally to give a largely qualitative indication of the strong ground motions produced by an earthquake. It consists of a smoked watch glass attached to a two-degree-of-freedom pendulum with a period of 34 sec and damping about 10 per cent of critical; a pen records the pendulum motions on the watch glass. One point on the displacement spectrum of the recorded ground motion at this period and damping is obtained from the measurement of the maximum pendulum excursion.

An examination of the seismoscope record obtained on the east abutment of the failed Lower San Fernando dam during the 1971 San Fernando earthquake showed a high-frequency vibration superimposed on the general oscillations. It did not seem likely that this was solely an earthquake vibration component, and shaking table tests of seismoscopes revealed the presence of a seismoscope vibration mode at frequencies of 15 to 18 Hz depending on the instrument. The oscillations due to this mode on the abutment seismocope record have, therefore, been used as timing marks, to enable the seismoscope equation to be solved for the input acceleration components. The results of the calculations are presented along with analyses of the seismoscope response to indicate the range of applicability. One other record, obtained on a seismoscope alongside a strong-motion accelerograph, was also analyzed for comparison with the recorded accelerations, to demonstrate the validity of the technique. The timing vibration appears on a number of seismoscope records.
Reflection, refraction and mode conversion of long-period surface waves and the measurement of Q−1 for free oscillations
Authors: Reiter Leon
Published: September 2021

abstract

Filtered time series of Rayleigh waves from 4 events recorded on the quartz accelerometer at the IGPP, Camp Elliott Station, were analyzed. Attenuation (Q−1) was computed for spheroidal fundamental modes (oS19 to oS24) from several sequences of time-lapsed records for each event. A five-fold variation in measured Q−1 (and some variations in peak frequency) was assumed to be the result of lateral inhomogeneities in earth structure. Utilizing the duality between Rayleigh waves and fundamental-mode spheroidal oscillations, model power spectra were computed by summing the simulated Fourier transforms of dispersed wave trains. The effect of lateral variations in earth structure resulting in reflection, refraction and mode conversion of fundamental-mode surface waves was simulated by changes in amplitude, phase angle, and group and component travel times. Assuming an anelastic 10,000/Q of 33.3 (Q = 300), the observed range of measured Q−1 (and peak frequency) variations was duplicated by models with up to 5 per cent of the fundamental-mode Rayleigh-wave energy being “scattered”, i.e., reflected, refracted or converted to higher modes. In the real Earth, this would call for lateral variations in velocity structure well below the upper few hundred kilometers of the mantle. Recent seismological investigations have suggested lateral variations at these depths.
Detection and analysis of multiple seismic events
Authors: Flinn E. A. , Cohen T. J. , McCowan D. W.
Published: September 2021

We compare several methods of analyzing short-period seismic records with the purpose of detecting multiple events. The data used were from a pair of chemical explosions at a dam site near Alma Ata, recorded at the seismic observatory at Mould Bay, Canada. The methods evaluated include visual analysis of the array-beam sums, multichannel matched filtering, autocorrelation analysis, and cepstral analysis. For matched filtering we used the recorded wave forms from a seismic event which occurred reasonably close to the Alma Ata site. Measurements using the spectra or the cepstra appear to be most accurate in determining the delay time between the two events. The analysis methods discussed here generally give results which are in good agreement with the announced time between the explosion and announced yield ratio.
Probabilistic seismic hazard analysis and design earthquakes: Closing the loop
Authors: McGuire Robin K.
Published: September 2021

Probabilistic seismic hazard analysis (PSHA) is conducted because there is a perceived earthquake threat: active seismic sources in the region may produce a moderate-to-large earthquake. The analysis considers a multitude of earthquake occurrences and ground motions, and produces an integrated description of seismic hazard representing all events. For design, analysis, retrofit, or other seismic risk decisions a single “design earthquake” is often desired wherein the earthquake threat is characterized by a single magnitude, distance, and perhaps other parameters. This allows additional characteristics of the ground shaking to be modeled, such as duration, nonstationarity of motion, and critical pulses. This study describes a method wherein a design earthquake can be obtained that accurately represents the uniform hazard spectrum from a PSHA. There are two key steps in the derivation. First, the contribution to hazard by magnitude M, distance R, and ɛ must be maintained separately for each attenuation equation used in the analysis. Here, ɛ is the number of standard deviations that the target ground motion is above or below the median predicted motion for that equation. Second, the hazard for two natural frequencies (herein taken to be 10 and 1 Hz) must be examined by seismic source to see if one source dominates the hazard at both frequencies. This allows us to determine whether it is reasonable to represent the hazard with a single design earthquake, and if so to select the most-likely combination of M, R, and ɛ (herein called the “beta earthquake”) to accurately replicate the uniform hazard spectrum. This closes the loop between the original perception of the earthquake threat, the consideration of all possible seismic events that might contribute to that threat, and the representation of the threat with a single (or few) set of parameters for design or analysis.
Attenuation of earthquake ground motion in Japan including deep focus events
Authors: Molas Gilbert L. , Yamazaki Fumio
Published: September 2021

New attenuation equations for peak ground acceleration and velocity for Japan are developed. The equations are derived using extensive data recorded by the new JMA-87-type accelerometers, which do not require instrumental corrections that the older SMAC-type accelerometers do. Earthquakes with depths up to 200 km are used to make the equation applicable to subduction zone regions, which are common in Japan. Effects of depth and local site on the attenuation are considered simultaneously with the distance dependence and magnitude dependence using a two-stage regression procedure to separate the magnitude dependence from the distance dependence. Since the resulting normal equations become singular, an iterative partial regression algorithm is proposed. It is found that for the same magnitude and distance, peak ground motion increases as depth increases. The variation of the station coefficients with respect to the corresponding soil-type classification is quite wide. The station coefficients for the peak ground acceleration are found to be weakly correlated with the general soil classification, while a stronger correlation was found for the peak ground velocity. The resulting attenuation relations are given by log10PGA=0.206+0.477MJ−log10r−0.00144r−0.00144r+0.00311h+cia,log10PGV=−1.769+0.628MJ−log10r−0.00130r−0.00144r+0.00222h+civ, where PGA (cm/sec2) and PGV (cm/sec) are the larger of the peak accelerations and velocities from two horizontal components, MJ is the JMA magnitude, r is the closest distance to the fault rupture, h is the depth, and ci is the station coefficient of the recording station. The mean of the coefficients of the JMA stations is given by ci = 0.
Application of bandlimited anelastic models to wave propagation in highly attenuative media
Authors: Liu Hsi-Ping
Published: September 2021

Because of its simple form, a bandlimited, four-parameter anelastic model that yields nearly constant midband Q for low-loss materials is often used for calculating synthetic seismograms. The four parameters used in the literature to characterize anelastic behavior are τ1, τ2, Qm, and MR in the relaxation-function approach (s1 = 1/τ1 and s2 = 1/τ2 are angular frequencies defining the bandwidth, MR is the relaxed modulus, and Qm is approximately the midband quality factor when Qm ≫ 1); or τ1, τ2, Qm, and MR in the creep-function approach (s1 = 1/τ1 and s2 = 1/τ2 are angular frequencies defining the bandwidth, and Qm is approximately the midband quality factor when Qm ≫ 1). In practice, it is often the case that, for a particular medium, the quality factor Q(ω0) and phase velocity c(ω0) at an angular frequency ω0 (s1 < ω0 < s2; s1 < ω0 < s2) are known from field measurements. If values are assigned to τ1 and τ2 (τ2 < τ1), or to τ1 and τ2 (τ2 < τ1), then the two remaining parameters, Qm and MR, or Qm and MR, can be obtained from Q(ω0). However, for highly attenuative media, e.g., Q(ω0) ≦ 5, Q(ω) can become highly skewed and negative at low frequencies (for the relaxation-function approach) or at high frequencies (for the creep-function approach) if this procedure is followed. A negative Q(ω) is unacceptable because it implies an increase in energy for waves propagating in a homogeneous and attenuative medium. This article shows that given (τ1, τ2, ω0) or (τ1, τ2, ω0), a lower limit of Q(ω0) exists for a bandlimited, four-parameter anelastic model. In the relaxation-function approach, the minimum permissible Q(ω0) is given by ln [(1 + ω20τ21)/(1 + ω20τ22)]/{2 arctan [ω0(τ1 − τ2)/(1 + ω20τ1τ2)]}. In the creep-function approach, the minimum permissible Q(ω0) is given by {2 ln (τ1/τ2) − ln [(1 + ω20τ21)/(1 + ω20τ22)]}/{2 arctan [ω0(τ1 − τ2)/(1 + ω20τ1τ2)]}. The more general statement that, for a given set of relaxation mechanisms, a lower limit exists for Q(ω0) is also shown to hold. Because a nearly constant midband Q cannot be achieved for highly attenuative media using a four-parameter anelastic model, a bandlimited, six-parameter anelastic model that yields a nearly constant midband Q for such media is devised; an expression for the minimum permissible Q(ω0) is given. Six-parameter anelastic models with quality factors Q ∼ 5 and Q ∼ 16, constant to 6% over the frequency range 0.5 to 200 Hz, illustrate this result. In conformity with field observations that Q(ω) for near-surface earth materials is approximately constant over a wide frequency range, the bandlimited, six-parameter anelastic models are suitable for modeling wave propagation in highly attenuative media for bandlimited time functions in engineering and exploration seismology.
Rotation of the principal stress directions due to earthquake faulting and its seismological implications
Authors: Yin Z.-M. , Rogers G. C.
Published: September 2021

Earthquake faulting results in stress drop over the rupture area. Because the stress drop is only in the shear stress and there is no or little stress drop in the normal stress on the fault, the principal stress directions must rotate to adapt such a change of the state of stress. Using two constraints, i.e., the normal stress on the fault and the vertical stress (the overburden pressure), which do not change before and after the earthquake, we derive simple expressions for the rotation angle in the σ1 axis. For a dip-slip earthquake, the rotation angle is only a function of the stress-drop ratio (defined as the ratio of the stress drop to the initial shear stress) and the angle between the σ1 axis and the fault plane, but for a strike-slip earthquake the rotation angle is also a function of the stress ratio. Depending on the faulting regimes, the σ1 axis can either rotate toward the direction of fault normal or rotate away from the direction of fault normal. The rotation of the stress field has several important seismological implications. It may play a significant role in the generation of heterogeneous stresses and in the occurrence and distribution of aftershocks. The rotation angle can be used to estimate the stress-drop ratio, which has been a long-lasting topic of debate in seismology.
Reliable automatic detection of long-period volcanic earthquakes at Long Valley caldera, California
Authors: Evans John R. , Pitt Andrew M.
Published: September 2021

Capturing the rare long-period (LP) volcanic earthquakes occurring in and near Long Valley caldera, California, is important to ongoing volcanic-hazards monitoring. It is difficult, however, because LP events are weak, emergent, and almost devoid of energy above a few hertz. Automatic systems designed for tectonic earthquakes routinely fail to capture LP events.

We applied a PC-based teleseism-specific event-detection computer program to capturing these events. Retuning the software for LP events involved only changing parameters originally designed for change in this algorithm. Our retuned algorithm has captured every known LP event at Long Valley from October 1992 through the end of 1994.

We monitored up to 16 stations known to produce good records of LP events, saving those events that triggered enough of these stations (typically 10 of 16) within a specified time window. The principal difficulty has been the algorithm's sensitivity to regional earthquakes, which have waveforms similar to LP events. During our test, the 1992 Landers, 1994 Northridge, and 1994 Double Springs Flat (Nevada) earthquakes each have swamped the detector, requiring careful, active management of PC disk resources.

The efficacy of this retuned algorithm and the poor performance of tectonic-earthquake detectors during some volcanic emergencies make this algorithm an attractive candidate for volcano monitoring.
SHwave propagation by discrete wavenumber boundary integral modeling in transversely isotropic medium
Authors: Karabulut Hayrullah , Ferguson John F.
Published: September 2021

An extension of the boundary integral method for SH waves is given for transversely isotropic media. The accuracy of the method is demonstrated for a simple flat interface problem by comparison to the Cagniard-de Hoop solution. The method is further demonstrated for a case with interface topography for both surface and vertical seismic profiles. The new method is found to be both accurate and effective.
Site amplification at five locations in San Francisco, California: A comparison ofSwaves, codas, and microtremors
Authors: Seekins Linda C. , Wennerberg Leif , Margheriti Lucia , Liu Hsi-Ping
Published: September 2021

We compare microtremor data to weak-motion S-wave and coda recordings at sites in San Francisco in order to clarify the range of applicability of microtremor data to ground-motion prediction. We also compare S-wave results to coda results. For each type of data, we compute spectral ratios of motions from two soil/rock station pairs and from an uphole/downhole pair in the Marina district. We compute horizontal/vertical ratios (Nakamura's method) at a soil site, a rock site, and the surface and borehole instruments. In the station-pair analyses, microtremor data show amplifications at the same fundamental frequency as S waves, but the frequencies of other peaks do not agree. The amplification at frequencies higher than 2 Hz is greater in the microtremor data. Station-pair ratios of coda data generally show spectral peaks occurring at the same frequencies, but with levels varying from one to four times the amplification from S-wave ratios. Nakamura's method of analyzing microtremors agrees better with S-wave station-pair results than the microtremor station-pair method over a limited frequency band that varies from station to station.
Statistical estimation of seismic hazard parameters: Maximum possible magnitude and related parameters
Authors: Pisarenko V. F. , Lyubushin A. A. , Lysenko V. B. , Golubeva T. V.
Published: September 2021

The problem of statistical estimation of earthquake hazard parameters is considered. The emphasis is on estimation of the maximum regional magnitude, Mmax, and the maximum magnitude, Mmax(T), in a future time interval T and quantiles of its distribution. Two estimators are suggested: an unbiased estimator with the lowest possible variance and a Bayesian estimator. As an illustration, these methods are applied for the estimation of Mmax and related parameters in California and Italy.
Real-time seismology at UC Berkeley: The Rapid Earthquake Data Integration project
Authors: Gee Lind S. , Neuhauser Douglas S. , Dreger Douglas S. , Pasyanos Michael E. , Uhrhammer Robert A. , Romanowicz Barbara
Published: September 2021

The Rapid Earthquake Data Integration project is a system for the fast determination of earthquake parameters in northern and central California based on data from the Berkeley Digital Seismic Network and the USGS Northern California Seismic Network. Program development started in 1993, and a prototype system began providing automatic information on earthquake location and magnitude in November of 1993 via commercial pagers and the Internet. Recent enhancements include the exchange of phase data with neighboring networks and the inauguration of processing for the determination of strong-motion parameters and seismic moment tensors.
Analysis of high-frequency Pg/Lg ratios from NTS explosions and western U.S. earthquakes
Authors: Taylor Steven R.
Published: September 2021

The high-frequency Pg/Lg discriminant is studied between frequencies of 0.5 and 10 Hz using 294 NTS explosions and 114 western U.S. earthquakes recorded at four broadband seismic stations operated by Lawrence Livermore National Laboratory. The stations are located at distances of about 200 to 400 km from the Nevada Test Site (NTS). Event magnitudes ranged from about 2.5 to 6.5, and propagation paths for the earthquakes range from approximately 175 to 1300 km. The discriminant is shown to be very effective and displays improved separation between earthquakes and explosions as frequency is increased. Because of propagation effects, it is important to apply distance corrections directly to the amplitude ratios or to the magnitude-corrected amplitudes prior to computing the ratios. Multivariate discrimination analysis using both maximum-likelihood Gaussian classifiers and a backpropagation neural network show that approximately 95% of the events can be correctly identified. Both classification procedures were designed to handle missing data filled in using a nearest-neighbor algorithm. Except for a few notable exceptions, most of the earthquake misclassifications occur for mb < 4, which is expected for events having reduced signal-to-noise ratios. All of the explosion misclassifications occur for mb < 4, suggesting a source or near-source effect rather than an effect of poor signal-to-noise ratio. The explosions that were misclassified were typically of magnitude large enough to be classified correctly by mb/Ms or Love-wave energy. The main drawback of the Pg/Lg discriminant is that, because of signal-to-noise considerations and propagation effects, the number of measurements are reduced considerably at higher frequencies. It is expected that the problem will be amplified as magnitudes are reduced and event-receiver distances are increased.
Mapping shallow heterogeneity with teleseismic P to Rg scattered waves
Authors: Revenaugh Justin , Mendoza Hal
Published: September 2021

Over 9000 records of teleseismic P-wave coda from the Southern California Seismic Network are used to map lateral variations in P to Rg scattering strength and the group velocity of scattered Rg. Building on the results of Revenaugh (1995a), we use the correlation of scattering strength and topographic roughness as an indicator of model fit to estimate group-velocity dispersion over five frequency bands between 0 and 3 Hz. Rg group velocity displays normal dispersion, decreasing from 2.7 ± 0.3 km/sec for frequencies between 0 and 0.6 Hz to a low of 2.2 ± 0.4 km/sec for the 2.0 to 3.0 Hz band. Lateral heterogeneity is introduced by assuming Rg velocity is a function of local topographic roughness. Grid-search/migration analysis yields group velocities of 2.2 and 2.85 km/sec for “smooth” and “rough” terrain, respectively, and a 150-m threshold for the local standard deviation of topography distinguishing “smooth” from “rough”. The map of scattering strength approximates topographic roughness throughout southern California, implying that teleseismic P-wave coda duration and relative amplitude level depend strongly on near-surface (<3 km) geology.
Toward real-time estimation of regional moment tensors
Authors: Pasyanos Michael E. , Dreger Douglas S. , Romanowicz Barbara
Published: September 2021

Recent advances in broadband station coverage, continuous telemetry systems, moment-tensor procedures, and computer data-processing methods have given us the opportunity to automate the two regional moment-tensor methods employed at the UC Berkeley Seismographic Station for events in northern and central California. Preliminary solutions are available within minutes after an event has occurred and are subsequently human reviewed. We compare the solutions of the two methods to each other, as well as the automatic and revised solutions of each individual method. Efforts are being made to establish robust criteria for determining accurate solutions with human review and to fully automate the moment-tensor procedures into the already-existing automated earthquake-location system.
Seismic hazard estimate from background seismicity in southern California
Authors: Cao Tianqing , Petersen Mark D. , Reichle Michael S.
Published: September 2021

We analyzed the historical seismicity in southern California to develop a rational approach for calculating the seismic hazard from background seismicity of magnitude 6.5 or smaller. The basic assumption for the approach is that future earthquakes will be clustered spatially near locations of historical mainshocks of magnitudes equal to or greater than 4. We analyzed the declustered California seismicity catalog to compute the rate of earthquakes on a grid and then smoothed these rates to account for the spatial distribution of future earthquakes. To find a suitable spatial smoothing function, we studied the distance (r) correlation for southern California earthquakes and found that they follow a 1/rµ power-law relation, where µ increases with magnitude. This result suggests that larger events are more clustered in space than smaller earthquakes. Assuming the seismicity follows the Gutenberg-Richter distribution, we calculated peak ground accelerations (PGA) for 10% probability of exceedance in 50 yr. PGA estimates range between 0.25 and 0.35 g across much of southern California. These ground-motion levels are generally less than half the levels of hazard that are obtained using the entire seismic source model that also includes geologic and geodetic data. We also calculated the overall uncertainty for the hazard map using a Monte Carlo method and found that the coefficient of variation is about 0.24 ± 0.01 for much of the region.
A Monte Carlo approach in estimating uncertainty for a seismic hazard assessment of Los Angeles, Ventura, and Orange counties, California
Authors: Cramer Chris H. , Petersen Mark D. , Reichle Michael S.
Published: September 2021

Maps of uncertainty and parametric sensitivity in ground motion have been produced for three southern California counties using a Monte Carlo approach. The uncertainty in hazard is estimated by random sampling a logic tree that has the uncertainty in most parameters described by a normal distribution. The nine parameters varied in the uncertainty analysis are those related to the estimation of recurrence rates for earthquakes on faults using geologic information, the ground-motion attenuation relations, the relations available for estimating the magnitude-frequency distribution of earthquakes on faults, and the inclusion or exclusion of blind thrusts in the Los Angeles area. Besides simultaneously varying all nine parameters for a Monte Carlo series of runs to obtain the overall uncertainty in ground motion for a fixed annual probability, each of the nine parameters were varied separately while the others were held fixed to determine the sensitivity of each parameter on this uncertainty. The total uncertainty in shaking levels corresponding to a fixed annual probability is up to ±50% at the 95% confidence level. The parameters that most influence the uncertainty in the hazard estimates from geologic information are (1) maximum magnitude, (2) choice of attenuation relations, (3) the magnitude-frequency distribution, and (4) slip rate.