bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequency-moment distribution of earthquakes in the Aleutian Arc: A test of the characteristic earthquake model
Authors: Davison Frederick C. , Scholz Christopher H.
Published: July 2021

The frequency-moment distribution of earthquakes is derived for discrete regions of the entire Aleutian Arc, both for segments which have ruptured in historic times and those regions which have been identified as seismic gaps. This distribution is then compared to the moment of the largest event in the respective region, or for gaps, the largest event which is likely to occur based on a plate-kinematic model of accumulated moment. Data for this study are based upon three data sources. Instrumental data are utilized for the 18 yr subsequent to the establishment of the World Wide Standardized Seismograph Network (WWSSN). Data for events of magnitude 7 and greater have been carefully collected and are presumed to be complete for the time period 1899 to present. The last data set is comprised of the largest event in each region, either an actual earthquake or the moment estimate based on current plate slip rates. Data were normalized to the recurrence time of the largest event in the respective zone. In all cases, the data seriously underestimate the largest moment event, indicating that a characteristic earthquake model is appropriate for individual fault zones. However, if the data are combined for the entire arc, the largest event is closely predicted. This indicates that a b-value model may be utilized only for regions in which there is a distribution in the size of earthquake producing faults.
Seismic noise in Fennoscandia, with emphasis on high frequencies
Authors: Bungum H. , Mykkeltveit S. , Kværna T.
Published: July 2021

As part of a siting survey for the NORESS small-aperture regional array, the seismic noise field for frequencies up to about 50 Hz was studied for various sites in Fennoscandia, with emphasis on the NORSAR siting area. Power spectral bias sources were studied in order to ensure a sufficient resolution and dynamic range. It was found that the 1-Hz noise level at NORSAR usually ranges from 1 to 10 nm2/Hz. Above 2 to 3 Hz, the noise power falls off at a rate of about f−5 to levels of about 10−5 nm2/Hz at 10 Hz and 10−8 nm2/Hz at 40 Hz. The slope is much steeper for lower frequencies, where levels between 104 and 108 nm2/Hz were observed at 0.2 to 0.3 Hz. The noise field shows variability both in time and space for frequencies below 2 to 3 Hz, and stability in time for higher frequencies, where essentially only cultural noise sources contribute to the variation. Windgenerated noise is usually negligible around 10 Hz, but contributes 5 to 15 dB at 20 to 30 Hz. Diurnal variations are about 2 dB at 4 Hz and negligible at low frequencies. Only small variations in noise levels are found throughout Fennoscandia, with slightly lower values for Finland and slightly higher for northern Norway, as compared to southeastern Norway. The spatial correlation properties of the noise show variability for frequencies below 2 to 3 Hz and stability for higher frequencies: in the 1- to 3-Hz band, the correlation coefficients drop to zero at interstation distances ranging from 800 to 1500 m, and in the 3- to 5-Hz range from 400 to 500 m. After reaching zero, the correlation values usually approach a level of about −0.2 before increasing again. A frequency dependence was also found for the propagational characteristics, with westerly noise directions dominating for frequencies of 1 Hz and below, and easterly directions in the 2- to 8-Hz range. The degree of randomness in the noise increases with increasing frequency, leaving only a small propagational part at 8 Hz. There is clear evidence for a difference in noise-generating processes below and above 2 to 3 Hz due to differences in spectral slope, in spectral time and space variability, in correlation characteristics, and in propagational characteristics.
MLobservations in the Great Basin andM0 versusMLrelationships for the 1980 Mammoth Lakes, California, earthquake sequence
Authors: Chávez David E. , Priestley Keith F.
Published: July 2021

The local magnitude distance correction term, log A0(Δ), has been estimated for paths within the Great Basin by converting seismograms of earthquakes in the vicinity of Mammoth Lakes, California, into equivalent Wood-Anderson seismograms and measuring the decay of peak amplitude with distance. The shape of the log A0(Δ) curve which results suggests more attenuation of energy in the Wood-Anderson passband than in southern California. For Great Basin paths we find, for events with ML ≦ 5.5, that

log A 0 ( Δ ) = { log 10 [ e − 0.016 R R ] − 0.31 0 ≦ Δ ≦ 9 0 km log 10 [ e − 0.006 R R 0.83 ] − 1.08 90 ≦ Δ ≦ 6 0 0 km

where Δ is epicentral distance, R=Δ2+h2 is hypocentral distance, and h is focal depth. Our data also suggest a magnitude bias in the correction term, in that for events above ML ≈ 5.5, peak amplitudes recorded at epicentral distances below 20 km decay less rapidly than those for smaller events recorded at the same sites. This observation is consistent with the hypothesis that there is a near-source saturation of ML due to the effects of a finite source size for large earthquakes. Using the revised magnitude scale and seismic moments, M0, estimated from spectral analysis, the data are well fit by the straight line

log ⁡ M 0 = ( 1.20 ± 0.05 ) M L + ( 17.49 ± 0.19 )

for 1 ≦ ML ≦ 6. M0 versus ML values from model calculations which assume constant stress drop predict curved moment-magnitude plots over this magnitude range. The fact that we observe a linear relationship suggests that the stress drop of these events is not constant but rather increases with ML, in particular for events above ML ≈ 5.5.
An empirical estimate of near-source ground motion for a major,mb= 6.8, earthquake in the eastern United States
Authors: Campbell Kenneth W.
Published: July 2021

Three empirical techniques are used to estimate ground-motion amplitudes in the near-source region of a major earthquake hypothesized to occur along the east coast of the United States. These techniques include the estimation of strong-motion parameters from the statistical analysis of selected strong-motion records, from empirical and theoretical attenuation relations, and from Modified Mercalli intensity. Source parameters for the hypothesized earthquake were selected to be similar to those inferred for the 1886 Charleston, South Carolina, earthquake. The epicentral region is characterized by a Modified Mercalli intensity of X, from which magnitudes of mb = 6.8, Ms = 7.2, and M = 7.2 were estimated. Inferred fault mechanisms for the hypothesized event vary from strike-slip on a vertical fault to reverse or reverse-oblique slip on a fault dipping as shallow as 45°.

The median estimate of peak horizontal acceleration for a point located 15 km from the surface projection of fault rupture is 0.30 g, independent of site geology. Corresponding estimates of peak horizontal velocity are 35 cm/sec for soil and soft sedimentary rock sites and 18 cm/sec for crystalline basement rock sites. Strong-motion parameters for a point located 15 km from the epicenter, corresponding to a point located directly above the rupture zone of the hypothesized earthquake, are estimated to be approximately 80 per cent higher than these estimates, or about 0.55 g for peak acceleration and about 63 and 33 cm/sec for peak velocity on soil/soft rock and crystalline rock, respectively. Corresponding velocity-acceleration ratios are 115 cm/sec/g for soil/soft-rock sites and 60 cm/sec/g for crystalline rock sites. Standard deviations associated with the natural logarithm of peak horizontal acceleration and velocity are estimated to be 0.5 and 0.7, respectively, representing an 84th percentile estimate (or equivalently an upper 68 per cent confidence limit) that is approximately 65 per cent higher than the median for acceleration and 100 per cent higher than the median for velocity. While these strong-motion values are generally higher than those currently used in the seismic design of most structures in the Eastern United States, their impact on the seismic safety of specific sites in the region will depend on an assessment of the probability of occurrence of an earthquake of this size within the near-source region of these sites.
Spatial and temporal variations in seismicity in the Imperial Valley (1902-1984)
Authors: Doser Diane I. , Kanamori Hiroo
Published: July 2021

abstract

Earthquakes with ML ≧ 4.5 that occurred between 1932 and 1973 in the Imperial Valley region and their related foreshocks and aftershocks are relocated using station delays derived from calibration events that were well recorded at regional distances between 1979 and 1981. The relocated seismicity shows that there was an increase in seismicity in regions northeast of the Imperial fault 5 to 6 yr prior to the 1940 (Ms = 7.1) Imperial Valley earthquake. A study of intensity reports for felt earthquakes prior to 1932 also suggests an increase in seismicity in regions surrounding the Imperial fault as early as 1917. Isoseismal patterns, description of the mainshock sequence, and patterns of seismicity before and after the 1915 Imperial Valley earthquakes suggest that the earthquakes occurred off the Imperial fault. In this case, seismicity between 1906 and 1940 would nearly encircle the portion of the Imperial fault that ruptured during 1940. In both the 1940 and 1979 Imperial Valley earthquake sequences, aftershocks of ML ≧ 4.5 occurred only for 2 months following the mainshock. The aftershock sequences were followed by periods of quiescence lasting up to 10 yr in the region within 30 km of the mainshock. This is in contrast to ML > 6.0 earthquakes occurring near the edges of the Imperial Valley that had aftershocks of ML ≧ 4.5 occurring for up to 4 yr after the mainshock. These differences may be related to the high heat flow within the Imperial Valley.
HYPOCENTER: An earthquake location method using centered, scaled, and adaptively damped least squares
Authors: Lienert Barry R. , Berg E. , Frazer L. Neil
Published: July 2021

We present an earthquake location method, HYPOCENTER, which combines features of the two well-known algorithms HYPO71 and HYPOINVERSE, with a new technique which we term adaptive damping. Each column of the linearized condition matrix T, which relates changes in arrival time to changes in hypocentral position, is centered and scaled to have zero mean and a norm of one. Origin time is defined as the mean arrival time minus the mean travel time. The three least-squares normal equations for hypocentral coordinates, with diagonal terms equal to one, are then solved iteratively by adding a variable damping factor, θ2, to their diagonal terms before inversion. If the residual sum of squares increases, we return to the previous iteration, increase θ2, then try again. This procedure, which we term adaptive damping, always results in residuals which are less than or equal to the HYPO71 or HYPOINVERSE residuals. We demonstrate HYPOCENTER by comparing it to HYPO71 and HYPOINVERSE using synthetic and real arrival time data for four- and eight-station seismic arrays.
A method for the inversion of refraction and reflection travel times for laterally varying velocity structures
Authors: Huang Huaiyong , Spencer Carl , Green Alan
Published: July 2021

In an attempt to speed up the lengthy process of modeling seismic refraction/wide-angle reflection data, a two-dimensional ray tracing routine is used as the basis for an automated travel-time inversion scheme. Laterally varying P-wave velocity structures are represented by arbitrary-shaped blocks of constant velocity gradient. Velocities, gradients, and boundary points of the blocks are parameters in the inversion scheme, and the input data are refraction and reflection travel-time arrivals from both directions of a reversed seismic line. Damped least-squares techniques are used to solve the equations of condition, and inversions are allowed to proceed automatically for several iterations. A synthetic example is presented, and the data from two reversed seismic refraction profiles recorded recently in eastern Canada are inverted to demonstrate the utility of the method under less than ideal conditions. The synthetic test demonstrates that several iterations of the procedure are necessary for accurate recovery of input models and provides a resolving power analysis of the problem, while the real data example produces models comparable to those obtained by experienced interpreters using trial and error methods.
The effect of strong-motion array configuration on source inversion
Authors: Miyatake Takashi , Iida Masahiro , Shimazaki Kunihiko
Published: July 2021

By using the method of prediction analysis, the accuracy of source inversion of strong-motion data is investigated for various arrays, and the effects of array configuration are evaluated. In the case of a circular array in which Ns array stations are uniformly distributed within radius R and when the strike-slip fault is located at the center of the array, an empirical relationship between the array parameters and the standard deviation of the seismic moment of each subfault, normalized by the seismic moment, is obtained as

σ M 0 = c ⋅ N e 2 ⋅ 10 R / 5 / N s

where c is a constant, and Ne is the number of subfaults. The constant c depends upon the fault mechanism (dip slip or strike slip), aspect ratio of the fault, focal depth, the array configuration, rupture mode (unilateral or bilateral), crustal structure, etc. However, it would be useful for both the source inversion study and a future installation plan of strong-motion arrays.

An application of the method to several specific cases leads us to conclude that highly dense local array is not advantagenous for source inversion, but an array covering the earthquake fault with equally spaced stations is of benefit to the source inversion.

Two cases of array configuration examined are a straight-line array, which is perpendicular to the fault and another straight-line array, which is parallel to the fault. The perpendicular array is unsuitable for source inversion, but the parallel array is advantageous for source inversion. Furthermore, the inversion study for the 1979 Imperial Valley earthquake is simulated for three cases of strong-motion station distributions (case A: 20 United States stations; case B: El Centro strong-motion array; and case C: all 26 stations of the United States and Mexico). Our simulation shows that case B gives a very poor result, and that the best of three is case C.
Amplitudes at the antipode
Authors: Butler Rhett
Published: July 2021

Seismic amplitudes of 1 Hz compressional waves at the antipode are estimated using the body-wave magnitude formula and corrections for focusing at the antipode. Compressional wave amplitudes are found to be larger at the antipode than at other distances outside of the source region itself. Ellipticity effects at the antipode are found to be significant only for PP away from the earth's poles and for PKP near the equator. The effects of lateral heterogeneity on antipode focusing are estimated. Implications for monitoring nuclear explosions are discussed. An antipode experiment using small (12 ton) chemical explosions opposite a seismic array is found to be viable.
A test of two techniques for recognizing systematic errors in magnitude estimates using data from parkfield, California
Authors: Habermann R. E.
Published: July 2021

Selections of events from seismicity catalogs on the basis of size are universally made on the basis of magnitude. Such a selection implicitly assumes that these magnitudes provide a temporally consistent measure of earthquake size or that systematic errors in magnitudes are constant. Several techniques can be used to test this assumption. Results of application of these techniques to local and teleseismic catalogs indicate that in many cases this assumption cannot be justified. Two different techniques for identifying changes in systematic errors in magnitude are described here and applied to recent seismicity data from Parkfield, California. One technique relies on comparisons of seismicity rates before and after a possible change in magnitudes. The other uses station magnitude corrections to redetermine magnitudes. Both of these techniques indicate that a systematic decrease in magnitudes by 0.18 to 0.19 units occurred at Parkfield during November 1984. This decrease was associated with the installation of six low-gain stations in the Parkfield region. It is clear that changes in stations distributions can have significant effects on magnitudes and that these changes must be accounted for in all seismicity studies which use magnitude as a selection criteria. The results of past studies which have not accounted for these changes must be reevaluated.
Exact evaluation of the response of a layered elastic medium to an explosive point source using leaking modes
Authors: Haddon R. A. W.
Published: July 2021

A simple and rigorous theory of leaking modes for liquid layer or SH elastic wave propagation problems is presented. By taking the frequency ω and wave-number k simultaneously as complex variables and choosing appropriate paths of integration in the ω-plane, the integration with respect to k is performed exactly using Cauchy residue theory. The remaining integration with respect to ω is then carried out by use of the Fast Fourier transform. The method is simply to apply, accurate, and computationally efficient. There are no spurious arrivals, and provided the number of points in the Fast Fourier transform can be taken sufficiently large, there are no restrictions on distance.

The theoretical results established in the paper show conclusively that complete seismograms, including all possible body waves, can be expressed simply as a superposition of modes. No branch line integrals are required, contrary to the widespread supposition in the literature.

The application of the theory is illustrated by producing complete theoretical seismograms for a model consisting of six liquid layers.
Rupture complexity of a moderate-sized (mb6.0) earthquake: Broadband body-wave analysis of the North Yemen earthquake of 13 December 1982
Authors: Choy George L. , Kind Rainer
Published: July 2021

The occurrence of the North Yemen earthquake of 13 December 1982 provides an important opportunity to study source properties of earthquakes in the southern Arabian Peninsula. Although moderate in size (mb 6.0), this earthquake is the largest to have occurred in the region since the deployment of the Global Digital Seismograph Network. P waves recorded at teleseismic distances can be obtained from stations of this network and of the Graefenberg array that are flat to displacement and velocity in the frequency range from 0.01 to 5.0 Hz. The broad bandwidth of the data is necessary for deriving a dynamic description of the earthquake as well as the static properties of the source. In contrast, inversions using only long-period data provide much less insight into the complexity of rupture. By fitting the displacement pulse shapes with synthetics, we find that the Yemen earthquake was a complex rupture consisting of two events that occurred about 3.0 sec apart. The depth of both hypocenters is estimated to be 7 km. The focal mechanisms of the events each have a nodal plane that strikes 340° and dips 60° to the east. However, the slip directions of the focal mechanisms are in slightly different directions, 230° and 300°, respectively. The total moment of the earthquake is 3.0 ×1025 dyne-cm, with the second event having three times the moment of the initial event. By inverting P-wave arrival time differences at each station, we find the second hypocenter is located 7.5 km from the initial hypocenter in a direction that is nearly colinear with the NNW-striking nodal plane of the focal mechanisms of each event. The trend of extensional ground cracks in the epicentral region and the predominant strike of composite focal mechanisms of locally recorded aftershocks are also in a NNW direction. From the consistency of these observations, we infer that the east-dipping NNW-striking nodal planes are the fault planes. The static stress drop of the first and second events are 44 and 31 bars, respectively. Inverting the energy flux in the velocity waveforms, we find the energy radiated by the earthquake is 4.8 ×1020 dyne-cm. This implies an average apparent stress of 4 bars.

At different times during the aftershock sequence, seismicity tended to cluster about one or another of two different planes which, although having roughly the same strike, had conjugate dips. One of these planes, delineated late in the aftershock sequence, coincides with the inferred fault plane for the main shock. The complexity of the main shock and of the aftershock sequence suggests that strain accumulated on a system of strongly interdependent faults. As the region became critically loaded, the effect of a major rupture was to critically stress faults adjacent to the initial nucleation. The second event of the main shock represents the rapid release of stress from the fault system, while the ensuing aftershock sequence represents the gradual release of stress.
Microseismicity and source mechanism study: Shillong Plateau, northeast India
Authors: Kayal J. R.
Published: July 2021

Microearthquakes recorded by two surveys in the Shillong Plateau during December 1982-July 1983 and January-February 1984, respectively, have been analyzed for seismicity and tectonic study in the region. Of 1,000 events recorded during the surveys, 180 events with reliable P and S readings (which are observed within 50 km radius of the network), are relocated by the homogeneous station method. It is found that the events are mostly confined within a depth range of 10 to 35 km. The seismicity, in general, may be correlated with the major geological structure/lineaments in the area. High rates of seismicity are observed in the Shillong and Tura areas. On the other hand, an aseismic zone is delineated to the east of Shillong.

Composite source mechanisms of two groups of microearthquakes show thrust-fault mechanisms. One group of microearthquakes (1982 to 1983) in the Shillong area shows pure thrust faulting with a SE-NW compressive stress (P axis), whereas the other group of microearthquakes (1984) in the Tura area shows thrust faulting with a strike-slip component and a ENE-WSW compressive stress (P axis). The stress orientations are compatible with the known tectonics of the region: collision of the Indian plate with the Eurasian plate at the Himalaya and subduction of the Indian plate beneath the Burmese plate at the Arakan-Yoma range.
Spectral scaling of earthquakes in the Miramichi region of New Brunswick
Authors: Chael Eric P.
Published: July 2021

Seismograms of 12 earthquakes in the Miramichi region of New Brunswick were analyzed to determine source scaling relations. The events ranged in magnitude from 3.3 to 5.8 (mbLg). P-wave spectra between 1 and 20 Hz were calculated using digital records from station RSNY (Δ = 6°). Spectral ratios were then formed using the main shock as a reference event. Because the travel paths were virtually identical for all of the signals, the spectral ratios yield the scaling of the sources as a function of frequency. The spectral ratio curves show a smooth progression with event size, with their separation decreasing toward higher frequencies. These data were compared with theoretical curves for source models whose displacement spectra roll off as ω−2 and ω−3 above the corner frequencies. The data strongly favor the ω−2 models; the ω−3 models predict greater variation across the 1- to 20-Hz band than is observed. Comparison of the P-wave scaling at 15 Hz with the Rayleigh wave scaling at a period of 8 sec indicates that stress drop may increase with moment for these events, although not as fast as Nuttli (1983) has suggested for intraplate earthquakes.
A novel technique for measuringLgattenuation—results from Eastern Canada between 1 to 10 hz
Authors: Chun Kin-Yip , West Gordon F. , Kokoski Richard J. , Samson Claire
Published: July 2021

Spectral amplitudes of regionally recorded Lg waves are studied in detail between 0.6 and 10 Hz, using vertical-component, velocity seismograms of the Eastern Canada Telemetered Network stations and a supplementary Seismic Research Observatory-type station at Glen Almond (GAC), Québec. We find that the site responses vary among these stations by more than a factor of 3 within the frequency range of interest. Furthermore, they are found to be strongly frequency dependent. Consequently, it is essential that they be taken into consideration in studies of Lg wave attenuation and Lg source spectra of regionally recorded seismic events.

We present a new method of measuring interstation surface wave attenuation, which is closely related to the conventional two-station method. While retaining all the desirable features of the conventional two-station method, the new technique, which we will call the “reversed two-station method,” allows simple, direct (one-parameter) determination of the Lg wave attenuation from sparse spectral data in a manner unaffected by station site effects and associated instrument error.

The reversed two-station method is successfully tested over weakly attenuating, short (53 to 210 km) interstation paths in eastern Canada, a difficult experimental condition by normal standards. The Lg attenuation coefficient (0.6 to 10 Hz) in eastern Canada is found to be frequency dependent and of the form γ(f) = 0.0008 f0.81 km−1. At higher frequencies, the Lg attenuation appears to be essentially frequency independent. This latter finding is preliminarily interpreted as evidence that regionally recorded Lg waves in the Canadian Shield are, as in the case of Lg waves propagating through the structurally complex Appalachian Province, contaminated by the high-frequency coda of Sn waves. The Lg contamination over the shield paths becomes severe starting at 14 Hz, twice the frequency above which the Lg signal propagating over the Appalachian Province becomes completely dominated by non-Lg arrivals.
Topographical and geological amplifications determined from strong-motion and aftershock records of the 3 March 1985 Chile earthquake
Authors: Çelebi M.
Published: July 2021

Site-response experiments were performed 5 months after the MS = 7.8 central Chile earthquake of 3 March 1985 to identify amplification due to topography and geology.

Topographical amplification at Canal Beagle, a subdivision of Viña del Mar, was hypothesized immediately after the main event, when extensive damage was observed on the ridges of Canal Beagle. Using frequency-dependent spectral ratios of aftershock data obtained from a temporarily established dense array, it is shown that there is substantial amplification of motions at the ridges of Canal Beagle. The data set constitutes the first such set depicting topographical amplification at a heavily populated region and correlates well with the damage distribution observed during the main event.

Dense arrays established in Viña del Mar also yielded extensive data which are quantified to show that, in the range of frequencies of engineering interest, there was substantial amplification at different sites of different geological formations. To substantiate this, spectral ratios developed from the strong-motion records of the main event are used to show the extensive degree of amplification at an alluvial site as compared to a rock site. Similarly, spectral ratios developed from aftershocks recorded at comparable stations qualitatively confirm that the frequency ranges for which the amplification of motions occur are quite similar to those from strong-motion records. In case of weak motions, the denser arrays established temporarily as described herein can be used to identify the frequency ranges for which amplification occurs, to quantify the degree of frequency-dependent amplification and used in microzonation of closely spaced localities.
Surface and near-surface effects on seismic waves—theory and borehole seismometer results
Authors: Shearer P. M. , Orcutt J. A.
Published: July 2021

A simple plane wave model is adequate to explain many surface versus borehole seismometer data sets. Using such a model, we present a series of examples which demonstrate the effects of the free-surface, near-surface velocity gradients, and low impedance surface layers on the amplitudes of upcoming body waves. In some cases, these amplitudes are predictable from simple free-surface and impedance contrast expressions. However, in other cases these expressions are an unreliable guide to the complete response, and the full plane wave calculation must be performed. Large surface amplifications are possible, even without focusing due to lateral heterogeneities or nonlinear effects. Both surface and borehole seismometer site responses are almost always frequency-dependent.

Ocean bottom versus borehole seismic data from the 1983 Ngendei Seismic Experiment in the southwest Pacific are consistent with both a simple plane wave model and a more complete synthetic seismogram calculation. The borehole seismic response to upcoming P waves is reduced at high frequencies because of interference between the upgoing P wave and downgoing P and SV waves reflected from the sediment-basement interface. However, because of much lower borehole noise levels, the borehole seismometer enjoys a P-wave signal-to-noise advantage of 3 to 7 dB over nearby ocean bottom instruments.
Energy-flux model of seismic coda: Separation of scattering and intrinsic attenuation
Authors: Frankel Arthur , Wennerberg Leif
Published: July 2021

A new model of seismic coda is presented, based on the balance between the energy scattered from the direct wave and the energy in the seismic coda. This energy-flux model results in a simple formula for the amplitude and time decay of the seismic coda that explicitly differentiates between the scattering and intrinsic (anelastic) attenuation of the medium. This formula is valid for both weak and strong scattering and implicitly includes multiple scattering. The model is tested using synthetic seismograms produced in finite difference simulations of wave propagation through media with random spatial variations in seismic velocity. Some of the simulations also included intrinsic dissipation. The energy-flux model explains the coda decay and amplitude observed in the synthetics, for random media with a wide range of scattering Q. In contrast, the single-scattering model commonly used in the analysis of microearthquake coda does not account for the gradual coda decay observed in the simulations for media with moderate or strong scattering attenuation (scattering Q ≦ 150). The simulations demonstrate that large differences in scattering attenuation cause only small changes in the coda decay rate, as predicted by the energy-flux model. The coda decay rate is sensitive, however, to the intrinsic Q of the medium. The ratio of the coda amplitude to the energy in the direct arrival is a measure of the scattering attenuation. Thus, analysis of the decay rate and amplitude of the coda can, in principle, produce separate estimates for the scattering and intrinsic Q values of the crust. We analyze the coda from two earthquakes near Anza, California. Intrinsic Q values determined from these seismograms using the energy-flux model are comparable to coda Q values found from the single-scattering theory. These results indicate that coda Q values are, at best, measures of the intrinsic Q of the lithosphere and are unrelated to the scattering Q.
Statistical methods for comparing directions to the orientations of focal mechanisms and Wadati-Benioff zones
Authors: Frohlich Cliff , Willemann Raymond J.
Published: July 2021

We propose simple graphical methods for evaluating whether a set of direction vectors are clustered with respect to particular directions, axes, or planes. As examples of these techniques, we present data concerning the relationship between: (1) aftershock/initial event geometry and nodal planes of focal mechanisms; (2) aftershock/initial event geometry and the plane of the Wadati-Benioff zone; and (3) B axes of focal mechanisms and the plane of the Wadati-Benioff zone.
The Impact of Economic Size of Government on Income Distribution: Evidence from OECD Countries
Authors: CEYHAN Turgay , KÖSTEKÇİ Ahmet , GÖV Abdullah
Published: July 2021

In this study, the relationship between taxes and public expenditures, that show the governmentˈs economic size and income distribution, is analyzed. In the study covering the period 2000-2017 for 24 OECD countries, the Two-Step System Generalized Method of Moments and the bootstrap version of Dumitrescu-Hurlin (2012) panel causality test were used. According to the results of the Two-Step System Generalized Method of Moments, the expansion in the governmentˈs economic size increases the inequality. Findings of the panel causality test show unidirectional causality from taxes and expenditures to Gini.
Влияние эстетического образования на развитие творческой одаренности обучающихся
Authors: Александрова Н.С.
Published: July 2021

В статье разбираются вопросы эстетического образования обучающихся, результатом которого может стать развитие одаренности детей в творческой области. Автор предлагает рассматривать современные концепции художественного образования на примере идей Н.А. Ветлугиной и Р.Г. Казаковой, Л.Г. Беляковой. Средства массовой информации позиционируют одаренность как характеристику современных детей, но делают это не корректно. Современные передачи повышают интерес родителей к этому феномену, но травмируют психику детей, внушая им, что они самые лучшие.
Результаты реализации идей Болонской декларации в российском математическом педагогическом образовании
Authors: Далингер В.А.
Published: July 2021

В статье анализируются основные направления реализации Болонской декларации и показано, каким образом они реализованы в российском математическом педагогическом образовании; отмечены основные пути и средства подготовки учителей математики в педагогических вузах в современных условиях.
Отражение изучения организма человека в мировом художественном искусстве
Authors: Хачатурьянц В.Е. , Теремов А.В.
Published: July 2021

Человек является самым сложным объектом изучения в биологии и отражением в изобразительном искусстве. Русская и мировая живопись богата выдающимися примерами изображения человека, как неиссякаемого источника творчества художника. Изучение человека со всеми его внешними и внутренними особенностями настолько важно и существенно, что учителю недостаточно на уроках использовать только материал учебников биологии и учебных пособий. Стоит вспомнить об анатомических рисунках и портретных картинах великих художников, которые подкрепят теоретический материал курса биологии и будут способствовать реализации интегрированного подхода с целью создания разносторонне развитой личности.
Методы и инструменты управления корпоративным PR региональной коммуникационной группы
Authors: Лочан С.А. , Безпалов В.В. , Федюнин Д.В.
Published: July 2021

Одним из приоритетных направлений деятельности специалистов по связям с общественностью является, собственно, управление этими связями общественности с субъектом PR, создание позитивного и вызывающего интерес имиджа для той или иной региональной организации, на которую он работает. Практически все нынешние организации, правительственные организации, социальные структуры, так или иначе, осуществляют свою деятельность, находясь в постоянном взаимодействии, как с внутренней, так и с внешней средой. Непрерывно находясь в этой сложной системе взаимодействий, эти связи могут оказать существенное влияние на деятельность региональной организации и принимаемые ею решения. Фактически, управление этими взаимодействиями становится одной из основополагающих функций региональной организации. Работа со связями с общественностью, в зависимости от поставленных на текущий момент целей способно решить различные задачи, но в фокусе неизменно будет оставаться создание эффективного корпоративного PR региональной организации, создание эффективного имиджа организации и дальнейшее его совершенствование, на основе чего формируется доверительное отношение к организации и её репутации.
Многомерный комплексный анализ в социально-экономических задачах института Уполномоченного по правам человека в Российской Федерации
Authors: Адмаев О.В.
Published: July 2021

Информационные массивы больших данных возникают не только в работе с техническими приложениями, но и находят широкое применение в социальной сфере. К средствам математического структурирования и обработки больших данных института Уполномоченного по правам человека в Российской Федерации относится и многомерный комплексный анализ.
Перспективы использования токоограничивающего устройства с применением сверхпроводящих материалов
Authors: Попова М.В. , Переверзев А.А.
Published: July 2021

Энергосбережение и эффективность в системах электропередачи являются важнейшими задачами в области электроэнергетики. Использование свойства сверхпроводимости, проявляющегося у проводящих материалов определенного химического состава при определенных температурных параметрах и сопровождающегося резким падением удельного электрического сопротивления до значений близких к нулю, даёт большие перспективы в развитии электроэнергетики. Использование явления сверхпроводимости приводит к снижению потерь электроэнергии при ее получении и передаче, возможности уменьшения в разы габаритов двигателей и генераторов, созданию сверхмощных магнитов, применяемых в промышленности, в научных исследованиях, в медицине и на железной дороге при достижении эффекта левитации. Существуют и некоторые недостатки, например, необходимость использовать достаточно низкие температуры для достижения данного свойства проводника, что на данной момент является не простой и дорогостоящей задачей. В связи с этим в настоящее время все больше уделяется внимания разработкам, направленным на повышение критической температуры сверхпроводимости. Также стоит задача развития технологий для равномерного охлаждения проводников и надежной изоляции от воздействия окружающей среды. Но, несмотря на некоторые недостатки в работе со сверхпроводящими материалами, технология признана актуальной в решении задач энергосбережения при передаче больших потоков электроэнергии [2].
Анализ влияния технического состояния систем автомобиля на безопасности дорожного движения
Authors: Якунин С.Н. , Широбоков А.И.
Published: July 2021

Цели и задачи исследования. Провести анализ влияния технического состояния систем автомобиля на безопасности дорожного движения. Актуальность исследования. Актуальность исследования определена наличием сложной ситуации связанной с аварийностью на транспорте. Методы исследования. Общенаучные методы, их особенности, принципы и задачи их использования в экспертных автотехнических исследованиях. В качестве показателей приведены статистические данные аварийности. Основные результаты. Выявлено, что количество дорожно-транспортных происшествий в следствии технического состояния транспорта носит скрытый характер, и реальной картины отображающей масштаб аварий по причине выхода из строя той или иной системы не известен.
Некоторые особенности адыгейско-русской интерференции субординативного типа
Authors: Багироков Х.З. , Хейшхо Ф.И. , Кахужева З.К.
Published: July 2021

В условиях адыгейско-русского контактного билингвизма, требуют исследования характеристики, вербализирующие кодовую систему русской речи, т. е. русскую речь адыгейцев в социолингвистических условиях языковых контактов. Научно-теоретическая значимость работы заключается в выявлении объема и статуса интерферем, функционирующих в речи, выполняющих коммуникативную функцию. Актуальность статьи обусловлена важностью изучения деятельности билингвальной личности в условиях языковых контактов. Практическая ценность работы в репрезентации фонетико-фонологических основ, реализуемой в русской устной и письменной речи адыгейцев для повышения речевой культуры. Поставленные задачи определили методы: описательный, идентификационного анализа фонем контактирующих языков.
Design and evaluation of albumin nanoparticles for the delivery of a novel β-tubulin polymerization inhibitor
Authors: Spada Alessandra , Emami Jaber , Sanaee Foroughalsadat , Aminpour Maral , Paiva Igor, M , Tuszynski Jack , Lavasanifar Afsaneh
Published: July 2021

Purpose: The ultimate goal of this study is to develop a novel delivery system for a new potent cytotoxic compound, CCI-001, with anti-b tubulin activity, so that the drug can be effectively administered and at the same time its harmful side effects can be reduced. Methods: In the current study, CCI-001 was loaded into serum albumin (SA), using a modified desolvation method, generating CCI-001-SA nanoparticles. Both bovine and human SA were used for the encapsulation of this drug candidate. Optimum conditions for drug loading were achieved when already formed and crosslinked albumin nanoparticles were incubated overnight at 37°C with CCI-001 solutions. The CCI-001-loaded albumin nanoparticles were assessed for average particle diameter and polydispersity, zeta potential, drug loading, in vitro release, morphology and cell toxicity against SW620 and HCT116 colorectal cancer cells. Results: The spherical nanoparticles obtained were negatively charged (~ -30 mV) and had an average diameter of ~ 130 nm, with a narrow size distribution. The in vitro release of CCI-001 from the albumin nanoparticles showed a sustained release pattern over 24 hours without any initial burst release, compared to the fast release of the free drug under experimental conditions. No difference between the SA from the two species in terms of CCI-001 loading was observed. However, a significant difference was observed between the release profiles of CCI-001 from drug-loaded HSA and drug-loaded BSA nanoparticles with HSA nanoparticles showing slower drug release (mean release time, MRT, values of 5.14 ± 0.33 h and 6.88 ± 0.15 h for BSA-NPs and HSA-NPs, respectively, P < 0.01). Cellular toxicity studies showed higher cytotoxicity for CCI-001-SA compared to the free drug (IC50s of 0.62 ± 0.31 nM vs 2.06 ± 0.29 nM in SW620 cells and 0.9 ± 0.1 nM vs 4.2 ± 0.2 nM in HCT116 cells, for CCI-001-HSA NPs and free drug, respectively). Therefore, despite the low drug content level in the HSA nanoparticles of CCI-001, the formulation provides relevant concentrations for further in vivo studies in animal models due to high drug potency. Conclusions: The data support the potential use of albumin as a nanocarrier for CCI-001 in biological systems.
Experimental Modeling of the Ultra-Necrotic Stage of Critical Ischemia
of the Lower Limbs
Authors: Sukovatykh Boris Semenovich , Feyziev Elvin Eynulla , Belous Alexander Sergeevich , Trubnikova Elena Vladimirovna , Sukovatykh Mikhail Borisovich , Orlova Anzhelika Yurievna
Published: July 2021

Objective. So far, no experimental model of the necrotic ulcerative stage of critical limb ischemia has been created. Aim. Development of a method for modeling the necrotic ulcerative stage of critical lower limb ischemia.Materials and methods. The experimental study was carried out on 120 rats - males of the "Wistar" line, divided into 4 groups of 30 animals each. In the first group (intact), the level of microcirculation in the muscles of the hind limb was determined. In the second (sham-operated) group, ischemia was not simulated, but the neurovascular bundle of the thigh was isolated and the wound was sutured. In the third group (comparison), the modeling of chronic ischemia of the leg muscles was performed by removing the femoral, popliteal, anterior and posterior tibial arteries. In the fourth (experimental) group, to simulate chronic critical ischemia of the leg muscles, the femoral, popliteal, anterior and posterior tibial arteries and veins were removed, and the peripheral nerve was damaged.In the postoperative period, the dynamics of symptoms of limb ischemia was monitored. Animals were taken out of the experiment, 10 animals in each group by an overdose of anesthesia on the 10th, 21st and 28th days. Before hatching, the level of microcirculation was determined using laser Doppler flowmetry. To study the morphological picture at the same time in the third and fourth groups, the ischemic gastrocnemius muscle of the leg was excised and a standard histological examination was performed.Results. Trophic disorders in animals of the third group developed in 13.3%, and in the experimental group - in 100%. In the experimental group, the level of microcirculation at all periods was significantly less than in the comparison group: on the 10th and 21st by 1.3 times, on the 28th day by 1.2 times, and the area of ​​muscle necrosis was greater by the same days by 21.2%, by 8.2% and by 6.8%.Conclusion. The developed experimental model corresponds to the necrotic ulcerative stage of critical ischemia in humans.
Laboratory Signs of Enteric Failure - Predictors of Pressure Ulcers
in Traumatic Spinal Cord Disease
Authors: Baleev Mikhail , Ryabkov Maxim , Perlmutter Olga , Fraerman Alexander , Smirnov Igor , Leontiev Andrey , Sheiko Gennady , Efanov Oleg
Published: July 2021

Relevance. Among the complications of traumatic spinal cord disease (SCD) pressure ulcers occupy a special place, with incidence reaching 68% and showing no tendency for decreasing. Literature reviews one of the main reasons for the formation of decubital ulcers is enteral insufficiency, the timely detection of which is still a common problem for many medical specialties, and laboratory indicators pointing to its manifestation remain in the zone of a controversial issue. New knowledge regarding laboratory predictors of pressure ulcer formation in the acute period of trauma will reduce the risk of decubital ulcerative defects.Purpose of the study. Based on the analysis of laboratory blood levels in the acute and early periods of hip joint injury, to identify predictors of the formation of pressure ulcers in patients with spinal trauma.Materials and methods. 68 case histories of adult patients with hip injury were retrospectively analyzed. The victims were treated in the City Clinical Hospital No. 39 of the Kanavinsky District of Nizhny Novgorod for the period from 2013 to 2020.Results and discussion. A comparative analysis of blood levels on the first day after injury showed that patients with subsequently developed bedsores at the early stages of treatment got hypoproteinemia and a decrease in serum creatinine levels more often than patients without bedsores. In addition, white blood cell count in patients with pressure ulcers was elevated, compared to normal values and patients without pressure ulcers white blood cell count. For a year creatinine and total protein values in patients of the main group tended to be or completely became normal, which is most likely associated with adequately administered enteral nutrition. The white blood cell count of the study group decreased to the normal range.Conclusion. Increased white blood cell, a decrease creatinine levels and total protein values in patients with HSC in the first hours after injury confirms the catabolic orientation of metabolism in the acute period of spinal cord injury, so it leads to conclusion that the early intensive therapy aimed at arresting protein losses and inflammation is needed, which in turn will prevent the formation of pressure ulcers in the early period of traumatic spinal cord disease.
Nicaragua mestiza versus Nicaragua multiétnica: el caso de la Costa Caribe
Authors: Osorio Mercado Hloreley , Serra Vásquez Luis Héctor
Published: July 2021

Nicaragua experimentó las colonizaciones española y británica, además de distintos mestizajes. Pero en el imaginario, el mestizaje refiere únicamente al cruce entre lo indígena e hispano. Este artículo discute comparativamente el discurso y la experiencia de los proyectos de la Nicaragua mestiza (1894-1987) y la multiétnica, que desde 1987 reconoce que el pueblo nicaragüense es indígena, afrodescendiente y mestizo. Se argumenta que el proyecto de la Nicaragua mestiza sigue latente y cuenta con los mecanismos políticos-económicos-culturales que podrían eliminar a los indígenas y afrodescendientes de la Costa Caribe.