bluuebunny/crossref_metadata_2025 huggingface dataset:
The resolution of seismic instruments used in treaty verification research
Authors: Herrin Eugene
Published: July 2021

abstract

The resolution of the seismic sensors discussed in this paper is limited either by the self-noise of the system or the ambient ground noise at the observing site. The resolution limits of a particular system are frequency dependent. A major objective of the designer is to insure that seismic sensors are available which will be limited in resolution only by the ambient background noise at the quietest sites over the frequency band of interest in treaty verification research. This paper presents a review of the data currently available on the limiting resolution of the most advanced instruments used in this research program.
Steady-state response of an elastic half-space to a moving dislocation of finite width
Authors: Enrique Luco J. , Anderson John G.
Published: July 2021

abstract

An analytical method to evaluate the transient response on the surface of an elastic half-space for a kinematic dislocation over an infinitely long fault of finite width and arbitrary dip is presented. The model includes finite rupture velocities in the direction of both the strike and dip of the fault. In this sense, it differs from previous two- and three-dimensional models which typically assume one of these velocities to be infinite. In addition to the effects of the free boundary, the model considers a slip vector in an arbitrary direction. The assumptions of infinite fault length and uniform rupture velocities account for the relative simplicity of the solution which is invariant to an observer moving along the strike of the fault with a speed equal to the rupture velocity. These assumptions limit the applicability of the solution to near-field locations far from the ends of realistic faults. A limited set of numerical results illustrating the types of pulse shapes obtained by use of this model, and, some tests to validate the derivation and the numerical results are presented.
An error analysis of frequency-time analysis
Authors: Feng Chi-Chin , Teng Ta-liang
Published: July 2021

abstract

The temporal resolution and accuracy of frequency-time analysis (FTAN) as applied to surface-wave dispersion analysis are examined for a period range from 10 to 200 sec. The constant relative bandwidth filter (Dziewonski et al., 1969), optimum bandwidth filter (Inston et al., 1971), and display-equalized filter (Nyman and Landisman, 1977) are carefully examined with respect to their adequacy of application over a broad period range. Among these Gaussian filters, the optimum bandwidth filter gives a better performance for relatively short-period (less than 50 sec) dispersion measurement. To measure surface-wave dispersion for a broad period range, a “matched-filter FTAN” technique is introduced by modifying the “residual dispersion measurement” technique (Dziewonski et al., 1972). A detailed numerical analysis is made on this new technique; the result demonstrates a significant improvement on both the resolution and the accuracy of surface-wave dispersion data extraction over a broad period range up to at least 200 sec.
Application of image enhancement and pattern recognition algorithms to seismic reflection data
Authors: McMechan George A.
Published: July 2021

abstract

A digital seismic reflection section may be converted to a gray scale image composed of pixels and processed with techniques borrowed from the disciplines of image enhancement and pattern recognition. Types of processing include scaling, thresholding, density equalization, filtering, segmentation, and edge-finding. These are successfully applied to a migrated common mid-point seismic reflection line that traverses the Queen Charlotte fault (located in the northeastern Pacific Ocean). The result is the definition and enhancement of an elongated, near-vertical reflectivity anomaly associated with the Queen Charlotte fault.
Source processes of large earthquakes along the Xianshuihe fault in southwestern China
Authors: Zhou Huilan , Liu Hsui-Lin , Kanamori Hiroo
Published: July 2021

abstract

The Xianshuihe fault is one of the most active faults in southwestern China. Recently, three large earthquakes occurred along it in 1967 (Ms = 6.1), 1973 (Ms = 7.5), and 1981 (Ms = 6.8).

The 1981 event occurred near the central portion of the fault zone. Modeling of the body and surface waves indicates pure left-lateral strike-slip motion on a vertical fault striking N40°W consistent with the surface trend of the Xianshuihe fault. Two major ruptures are suggested for this source, with a total moment of 1.3 ×1026 dyne-cm. The 1973 event occurred about 65 km northwest of the 1981 event and ruptured about 90 km bilaterally along the fault. The body-wave synthetics indicate three main ruptures during faulting within 43 sec, with a total moment of 1.8 ×1027 dyne-cm. The mechanisms are similar to the 1981 event, and the average slip is determined to be 3.8 m. The largest aftershock (Ms = 5.9) occurred 1 day after the main event with a normal-fault mechanism striking almost perpendicular to the surface breakage. The 1967 event occurred at the northwestern end of the fault zone, with a strike of N65°E. It had a nearly normalfault mechanism with a seismic moment of 4.5 ×1025 dyne-cm. The largest aftershock (Ms = 5.1) occurred 7 hr later with a similar focal mechanism.

The primary faulting along the Xianshuihe fault is left-lateral strike-slip, but the normal faulting with strike direction about perpendicular to the Xianshuihe fault trace is common, especially in the northwestern segment. The faulting pattern in this region is consistent with the regional stress field caused by the India-Tibet collision. The normal event which is not on the major fault seems to have more frequent foreshocks and aftershocks than those on the main fault.
Spatial attenuation of theLgwave in the Central United States
Authors: Dwyer John J. , Herrmann Robert B. , Nuttli Otto W.
Published: July 2021

abstract

The spatial attenuation of the Lg wave in the Central United States is studied in the time domain in the frequency range of 1 to 10 Hz. Fitting Lg amplitudes according to the relation

A = A o r − 5 / 6 exp ( − γ r ) ,

γ varies between 0.0007 ± 0.0001 km−1 at 1 Hz and 0.0029 ± 0.0005 km−1 at 10 Hz (standard errors given). Relating γ to Qβ by the relation

γ = π f / Q β U ,

these results imply a frequency dependence for Qβ given by

Q β ( f ) = Q β ( 1 H z ) f ( 04 ± 015 ) .

This result extends Singh's (1981) estimate of 0.1 to 0.3 for the exponent of frequency dependence for the frequency range to 0.5 to 2 Hz for coda waves observed in the Central United States.

Bandpassed microearthquake data were also used to estimate source spectrum shapes and seismic moments. Incorporating these results with those of Street et al. (1975), the seismic moment-magnitude scaling for the Central United States is found to be

log 10 M o = 16.44 ± 0.18 + ( 1.26 ± 0.05 ) m b L g

for the magnitude range 1.8 ≦ mbLg ≦ 4.9.
A study of the 20 January 1982 earthquake near Great Nicobar Island, India
Authors: Agrawal P. N.
Published: July 2021

abstract

An earthquake of MS = 6.3 occurred on 20 January 1982 near the east coast of Great Nicobar Island (in the Bay of Bengal), India and caused great panic among the inhabitants. Ground Fissures and damage to civil engineering structures was also caused. A study comprised of the recording of aftershocks and their migration, the preparation of an isoseismal map, and the compilation of other damage data is presented. Some recommendations have been made to permit suitable safeguards in future development.
Digitization noise and accelerograph pen offset associated with Japanese accelerograms
Authors: Crouse C. B. , Matuschka Trevor
Published: July 2021

abstract

Ground-motion accelerograms recorded in Japan between 1956 and 1978 were recently processed. Preprocessing studies of the accelerograms were required that consisted of: (1) evaluation of the long-period digitization noise in the accelerograms, and (2) correction for initial offset of the recording pen in the SMAC accelerograph. Long-period digitization noise present in each accelerogram was identified from the Fourier Amplitude Spectrum of the uncorrected accelerogram. Similar investigations with United States accelerograms recorded on 70-mm film revealed that the noise in both sets of data had similar characteristics. In nearly all cases, the noise spectrum was proportional to the period, which suggested that fatigue and carelessness of the operator during digitization may have been responsible for the observed period dependence. Correction for initial pen offset was necessary for some Japanese accelerograms because the pen arm was not parallel to the direction of movement of the recording paper. To account for pen offset, values of the initial pen rotation were assumed, and the accelerograms were corrected using a simple algorithm. Our best estimate of the true offset was based not only on the offset which best removed the slanted appearance, but also the offset inferred from the original accelerogram.
Source parameters and scaling laws of the 1978 Swabian Jura (southwest Germany) aftershocks
Authors: Scherbaum Frank , Stoll Dieter
Published: July 2021

The 3 September 1978, Swabian Jura (southwest Germany) earthquake (MWA = 5.7) was followed by a large number of aftershocks which have been recorded with a local network of five portable seismic stations. The seismic moments, fault radii, and the static stress drops have been determined from the SH displacement spectra using the Brune (1970) source model. The data set is consistent with the Gutenberg-Richter energy-magnitude relation.

Below a Wood-Anderson magnitude of about 4, the corner frequencies increase only slowly with decreasing magnitudes. No corner frequency higher than 15 Hz has been observed in the magnitude range down to 0.8. Correspondingly, the high-frequency decay slopes show a strong increase when the corner frequencies are approaching the maximum frequency. This prevents the use of slope data for Q determinations.

In terms of the Madariaga (1977) crack model, the data show a strong influence of source complexities on the smaller events.
Wave propagation in a three-dimensional circular basin
Authors: Lee Jia-Ju , Langston Charles A.
Published: July 2021

Wave propagation in a three-dimensional circular basin model is studied by using a ray technique which employs the method of principal curvature for geometric spreading calculation. Three components of ground motion are calculated at surface stations assuming incident plane P and SH waves with various incidence angles. Computed results show that seismic energy is substantially enhanced in the central region of the basin while it diverges rapidly toward the edge of the basin. Compared to a two-dimensional basin with the same cross section, amplitudes are larger for stations in the central region and smaller for stations near the edge. Waveforms and amplitudes can change drastically between two nearby stations due to caustics and geometric focusing for different paths. It is found, for the particular basin geometry and velocity contrast used, that the first multiple P wave and other particular phases experience two caustics near the basin center which are associated with the principal curvatures of the wave front. This results in the reversal of the polarity of the waveform. As incidence angle increases, later arrivals at near-edge stations and the stations in the diagonal direction are more strongly developed from the curved boundary of the basin, but amplitudes of ground motions generally decrease as incidence angle increases. In general, wave responses strongly depend on the incidence angle and station location. These results have important implications for site amplification of strong ground motions since wave behavior is so complex even for this simple idealized structure.
Nongeometric arrivals due to highly concentrated sources adjacent to plane interfaces
Authors: Daley P. F. , Hron F.
Published: July 2021

A high-frequency approximation for nongeometrical arrivals due to highly concentrated sources adjacent to the interfaces between two different elastic media has been developed following their detection in the real field data by Gutowski et al. (1982). In our approach, the “★” waves are associated with secondary saddle-point contributions of the contour of integration circumventing branch points in the integral representation of transmitted wave field. Our formulas are presented in a simple form suitable for an easy incorporation into any ray synthetic seismogram computation. The range of validity of our approximations is discussed and their accuracy tested by comparing the pertinent ray seismograms with their equivalents produced by the Alekseev-Mikhailenko method. A good match between both sets of seismograms suggests that our high-frequency approximations for “★” waves are well justified as are our formulas derived for the head wave-like arrivals driven by the “★” waves, and seen in the full wave field seismograms and detected in real data as well.
The viscoelastic reflection/transmission problem: Two special cases
Authors: Krebes E. S.
Published: July 2021

In the general problem of plane wave reflection and transmission at a boundary separating two linear viscoelastic media, the mathematical formulas for the reflection and transmission coefficients, the transmission angle, the attenuation vector, etc., are not easily interpretable because they cannot easily be expressed in terms of the basic input parameters (Q, incidence angle, etc.). To gain further insight, we study two special cases in which mathematical simplifications occur. No low-loss approximations are involved. In the first case, the incident wave is homogeneous, and the Q values of the two layers are equal, and we find, among other things, that the reflection and transmission coefficients are the same as the ones for perfect elasticity (they do not involve complex velocities, etc., and are independent of Q). In the second special case, the degree of inhomogeneity of the incident wave approaches its upper limit, and we find that the reflection and transmission coefficients approach constant (complex) values independent of the incidence angle, and that there is almost no ray-bending (refraction) upon transmission of the incident wave through the boundary.
Microearthquakes and the nature of the creeping-to-locked transition of the San Andreas fault zone near San Juan Bautista, California
Authors: Bakun William H. , McLaren Marcia
Published: July 2021

Eighteen digital event recorders were deployed during May-June 1981 along the creeping-to-locked transition of the San Andreas fault zone near San Juan Bautista, California, as a supplement to the U.S. Geological Survey's central California seismic network. Analysis of 18 well-recorded microearthquakes (0.7 ≦ ML ≦ 2.8) located along the transition confirms the complexity of the crust and fault-zone structure of the transition region. Seismic-wave site amplification is 2 to 10 times greater at sites between the San Andreas and Sargent fault traces, consistent with other evidence for lower velocities in the upper 3 km of crust there. Routine mislocation of epicenters 2 to 4 km northeast of the Sargent fault are consistent with greater P-wave velocity northeast of the Sargent fault. Microearthquake source parameters are consistent with a more segmented and splayed fault geometry toward the northwest locked end of the transition. P-wave nodal planes for 10 microearthquakes located to the northwest, 9 on the Sargent fault, and 1 near the San Andreas, are oriented more westerly than nodal planes commonly obtained for the frequent moderate-size earthquakes on the creeping section of the San Andreas fault to the southeast. Static stress drop, dynamic stress drop, and apparent stress estimates all increase with seismic moment, with the apparent stress and dynamic stress drops equal to about 3 and 20 per cent, respectively of the static stress drop. Average fracture energies, calculated assuming complete stress drop, generally increase with source size (seismic moment, rupture area, seismic slip, etc.) from 7 to 3000 J/m2; the two events with anomalously low fracture energies occurred on the creeping section of the San Andreas fault.
Use of seismoscope records to determineMLand peak velocities
Authors: Boore David M.
Published: July 2021

More information about ground motion can be extracted from seismoscope records than a single point on a response spectrum. To demonstrate this, the relation between seismoscope response and Wood-Anderson instrument output and peak horizontal ground velocity has been studied by simulating the various responses for a range of distances and magnitudes. The simulations show that the relation used by Jennings and Kanamori (1979) to convert from peak seismoscope readings to the peak response of a Wood-Anderson instrument has a distance- and magnitude-dependent systematic error. The error is negligible, however, for modern seismoscopes at distances of a few tens of kilometers. At several hundred kilometers, the relation underestimates the Wood-Anderson response by as much as a factor of two. The spread in Jennings and Kanamori's estimate of ML for the 1906 San Francisco earthquake, recorded on seismoscopes having relatively low natural frequencies (0.26 and 0.5 Hz), is reduced by the results in this paper—the upper value, from a seismoscope in Carson City, Nevada, at 290 km from the fault, going from ML = 7.2 to ML = 7.0 and the lower value, from Yountville, California (R ≈ 60 km), going from about 6.3 to 6.4. About 0.3 units of the remaining spread may be due to local geologic site conditions. If the 0.3 units is distributed equally between the Yountville and Carson City recordings, the estimates of ML for the San Francisco earthquake then become 6.5 and 6.8, somewhat lower than Jennings and Kanamori's final estimates of 634 to 7. Although the error in using the relation of Jennings and Kanamori to estimate Wood-Anderson response was at most a factor of 1.6 for the 1906 earthquake, the error can be substantially larger for smaller earthquakes recorded on similar low frequency seismoscopes.

The relation between Wood-Anderson and seismoscope response used by Jennings and Kanamori can be combined with an empirical relation between peak horizontal velocity and Wood-Anderson response to predict peak velocity from seismocope recordings. The simulations show that this relation (vmax = 8.1Awa, where vmax is the peak horizontal velocity in centimeters/second and Awa is one-half the range of the Wood-Anderson motion in meters) forms a lower bound for estimates of peak velocity from seismoscope recordings. The relation is good for stations within about 100 km of earthquakes with moment magnitudes of about 4.5 to 6.5, and it underestimates peak velocity by factors up to 2 or 3 for larger earthquakes at distances within 100 km. An application of the simulation method to the 1976 Guatemala earthquake (moment magnitude = 7.6) results in 37 cm/sec as a lower bound to vmax, with 66 cm/sec as a more likely value, from the seismocope recording in Guatemala City (approximately 25 km from the Motagua fault).
Seismic moments, local magnitudes, and coda-duration magnitudes for earthquakes in central California
Authors: Bakun William H.
Published: July 2021

Onscale seismograms recorded at stations in the U.S. Geological Survey's (USGS) central California seismic network (CALNET) have been used to estimate the seismic moment M0 and local magnitude ML for earthquakes of 1 ≦ ML ≦ 4 located on the San Juan Bautista and Parkfield sections of the San Andreas fault, the Coyote Lake section of the Calaveras fault, the Sargent fault, and near Livermore. These data, together with M0 and ML estimates for 4 ≦ ML ≦ 6 earthquakes in these areas, cannot be fit with a single linear log M0-versus-ML relation. Rather, the data are consistent with log M0 = 1.5 ML + 16 for 3 ≲ ML ≲ 6, with log M0 = 1.2 ML + 17 for 1 1/2 ≲ ML ≲ 3 1/2 and with a slope of ⅔ to 1 fro 1/2 ≲ ML ≲ 1 1/2.

Whereas USGS coda duration magnitude MD is consistent with ML for 1 1/2 ≲ ML ≲ 3¼, MD is larger than ML at ML ≲ 1 1/2 and smaller than ML at ML ≳ 3¼. Log M0 can be estimated to a precision of 0.2 for 1 ≦ MD ≦ 3 1/2 earthquakes in central California by applying log M0 = 1.2 MD + 17 to the MD that have been routinely published by the USGS.
Reconnaissance seismic refraction-reflection surveys in northwestern New Mexico
Authors: Jaksha Lawrence H. , Evans David H.
Published: July 2021

A velocity model of the crust in northwestern New Mexico has been constructed from an interpretation of direct, refracted, and reflected seismic waves. The model suggests a sedimentary section about 3 km thick with an average P-wave velocity of 3.6 km/sec. The crystalline upper crust is 28 km thick and has a P-wave velocity of 6.1 km/sec. The lower crust below the Conrad discontinuity has an average P-wave velocity of about 7.0 km/sec and a thickness near 17 km. Some evidence suggests that velocity in both the upper and lower crust increases with depth. The P-wave velocity in the uppermost mantle is 7.95 ± 0.15 km/sec. The total crustal thickness near Farmington, New Mexico, is about 48 km (datum = 1.6 km above sea level), and there is evidence for crustal thinning to the southeast.
Short- and long-period subevents of the 4 February 1965 Rat Islands earthquake
Authors: Mori Jim
Published: July 2021

Short- and long-period records of the P wave of the 1965 Rat Islands earthquake were analyzed to locate subevents within the main rupture. Four subevents were identified on the short-period records in the first 100 sec and on the two long-period records in the first 30 sec. The short-period subevents cluster in an area 100 km south of the initial epicenter which appears to be off of the main fault plane, an area in which two larger aftershocks have relatively high stress drops. The long-period subevents are located 90 km west of the initial epicenter. The times and locations of the first short- and long-period subevents indicate they were triggered by a front moving near the P-wave velocity.
Experimental study of soil-structure interaction at an accelerograph station
Authors: Crouse C. B. , Liang George C. , Martin Geoffrey R.
Published: July 2021

Forced harmonic vibration tests, using eccentric mass shakers, were conducted at the Jenkinsville, South Carolina, accelerograph station to determine the effect of soil-structure interaction on the motions recorded during four small magnitude earthquakes. The station consisted of a 4′ × 4′ × 2′ concrete pad that was embedded in a stiff clayey to medium sandy silt with a shear-wave velocity estimated at 500 fps. A five-foot-high wooden hut was attached to the pad and provided shelter to the SMA-1 accelerograph, which was bolted directly to the pad. The real parts of complex foundation impedance functions, which were obtained by solving the equations of motion for the vibration tests, were generally similar to the theoretical impedance functions for an embedded rectangular foundation. However, the imaginary parts, which are a measure of the foundation damping, were closer to the theoretical prediction for a surface foundation. The tests also showed that the soil-pad-hut system had two strongly coupled translational and rocking modes of vibration in the frequency range of 1 to 60 Hz. The first mode occurred at approximately 11 Hz (N40°W direction) and 17 Hz (N50°E direction) and involved mostly the response of the hut, while the second mode occurred at approximately 50 Hz in both directions and involved mostly the response of the concrete pad. Approximate transfer functions between the motions recorded at the station during the earthquakes and the free-field motions were computed from the experimental data. These functions showed significant amplification in the frequency band 20 to 50 Hz with a maximum amplification of 3 occurring at 50 Hz. Some measurable amplification also was observed at the fundamental natural frequencies in both directions. Calculations based on the transfer functions indicated that the average response spectra of the recorded earthquake motions were amplified by an average of about 30 per cent for frequencies greater than 15 Hz. These results suggest that careful attention must be given to the design of accelerograph stations if they are to record true ground motions over a wide frequency range.
Direct observation of rupture propagation during the 1979 Imperial Valley earthquake using a short baseline accelerometer array
Authors: Spudich Paul , Cranswick Edward
Published: July 2021

The 1979 Imperial Valley, California, earthquake (Ms = 6.9) was recorded on the El Centro differential array, a 213-m-long linear array of 5 three-component digital accelerometers 5.6 km from the nearest tectonic surface rupture. Although absolute time was not recorded on the array elements, a relative time base was established using the main shock hypocentral P wave and the P and S waves from a later aftershock. A cross-correlation technique was used to measure the difference in arrival times of individual seismic waves in a moving 0.6 to 1.2 sec window at each array element, which would then be converted into the wave's slowness (1/velocity) along the array. When applied to the main shock vertical and horizontal accelerograms, results from both components of motion indicated that the early arriving energy came from a source to the south of the array, and the source of the energy moved rapidly to the north of the array during the strong shaking. The ground motions at the array elements were well correlated for about the first 11 sec of motion. These observations suggest that we have observed the initiation of rupture south of the array and its subsequent propagation along the fault to a position north of the array in about 10 sec, and that the energy was radiated from a fairly compact region around the rupture front. If the observed vertical and horizontal ground motions are assumed to be caused by P and S waves, respectively, then the observed slownesses show irregularities which can be interpreted as implying that the observed high-frequency ground motions originated at irregularly distributed regions on the fault surface, or that the rupture velocity was variable, or both. One possible interpretation of the data suggests that the rupture proceeded at near P-wave velocity over a 7-km-long section of fault. Average rupture velocities of about 2.7 to 3.2 km/sec at 8 km depth are consistent with the data, and 2.8 km/sec is weakly preferred under the assumption that rupture propagates at a fixed fraction of the shear velocity. The large vertical pulse, which had a peak acceleration of 1.7 g at E06, was emitted from the portion of the fault extending 25 to 30 km northwest of the hypocenter near Meloland overpass, and not from the point on the fault closest to the differential array. Nothing can be said about fault behavior southeast of the hypocenter.
Very long-period data from the geoscope network: Preliminary results on great circle averages of fundamental and higher Rayleigh and Love modes
Authors: Roult G. , Romanowicz B.
Published: July 2021

We have analyzed the long-period Rayleigh and Love waves that were generated by four recent large earthquakes (New Ireland of 18 March 1983; Costa Rica of 4 April 1983; Honshu of 26 May 1983; and Chagos Islands of 30 November 1983).

Our records are those of the three-component very long-period stations (SSB, PCR, PAF, and TAM) of the GEOSCOPE network, that were in operation in 1983.

Available information from transverse and radial components is obtained; preliminary results concerning the fundamental modes of Love and Rayleigh waves, the first toroidal overtone, the second, and the third spheroidal higher mode are presented. For each of these particular modes, the phase velocities and sometimes the Q quality factors have been obtained, and the methods of data reduction are described in detail for future reference. The examples shown demonstrate, in particular, the benefits to be expected from a modern three-component very long-period network, as well as from original station locations.
Comparison of earthquake travel-time residuals or how to compare apples to oranges
Authors: Pavlis Gary L.
Published: July 2021

Comparing residuals from two earthquakes is difficult because earthquake locations interact with differences in three variables: (1) the spatial location of the source; (2) the set of stations that record each earthquake; and (3) the precision of individual arrival time measurements. Effective comparisons can be made by looking only at the components the residuals from two different earthquakes have in common. This is done with an operator that projects the residual vector for each event onto a subspace defined by the intersection of two linear manifolds related to the matrices of partial derivatives used to locate each earthquake. If one assumes the measurement error process is Gaussian, then under a null hypothesis of no differences in the travel-time anomalies between the two earthquakes, the sum of the squared differences in the projected residuals, has a chi-squared distribution with m∩ degrees of freedom, where m∩ is the dimension of the subspace of intersection. This is a the basis for a formal statistical test used to discriminate such anomalies.

Examples using synthetic data demonstrate the projection operator does work as predicted, but is limited to some extent by complications due to nonlinearity. The method is also applied to data from three earthquake swarms recorded by the Coso seismic network, in east-central California. These calculations reveal detectable differences in travel-time anomalies associated with these clusters of earthquakes. Apparently, significant lateral velocity variations exist at Coso over scales ≈ 2 km.
Q determined from local earthquakes in the South Carolina Coastal Plain
Authors: Rhea Susan
Published: July 2021

Coda Q, or Qc, is determined from the rate of coda decay in the Coastal Plain near Charleston, South Carolina. The mean of Qc calculated from individual estmates is near 190 at 1 Hz and increases to over 1650 at 10 Hz. A possible temporal change in Qc is identified, high values being associated with increased seismic activity during late 1977. Temporal changes have been observed elsewhere and laboratory measurements of Q under different stress states correlate high Q with high stress. A spatial variation in Qc is identified, increasing from west (Qc at 10 Hz equal to 850) to east (Qc at 10 Hz greater than 2100) across the Coastal Plain. The demarcation of high to highest zones of Qc is coincident with the western boundary of the innermost isoseismal of the Charleston 1886 earthquake. It is hypothesized that the 1886 earthquake was mislocated originally because of this spatial variation in energy attenuation that was unrecognized at that time.
The alleged earthquake in valencia in August 1427
Authors: Marinas J. M. López , Cervelló L. Bisbal
Published: July 2021

Some authors suppose the existence of an X-XI intensity earthquake which took place in Valencia in August 1427, based on the text from Al Maqrizy, an Arab author of the middle fourteenth century.

Such an earthquake is not registered in any Spanish earthquake catalog, and the Christian sources existing at the moment demonstrate that it could not happen at this moment and that the event belongs to the seismical period known as “Olotina Serie” which was felt between 1.427 and 1.428 in Olot (Gerona, Spain)
Stochastic time-predictable model for earthquake occurrences
Authors: Anagnos T. , Kiremidjian A. S.
Published: July 2021

Recent geophysical studies have indicated that an earthquake recurrence interval and the size of the preceding event are positively correlated. This observation is the basis for the deterministic time-predictable recurrence model of Shimazaki and Nakata. Using the basic assumptions of the time-predictable recurrence model, we develop a stochastic model of earthquake occurrence that incorporates temporal dependence. This paper discusses the formulation of the model and the effect of including temporal dependence. Hazard estimates for a section of the San Andreas fault near Parkfield, where data has suggested time-predictable behavior, are obtained for illustrative purposes. Comparisons are made with the Poisson model. Results indicate that currently used Poisson models may give lower estimates of the seismic hazard when there has been a seismic gap. Of the various sensitivity analyses performed, it is observed that slip rate has the largest effect on exceedence probabilites computed from the stochastic time-predictable model. Therefore, accurate determinations of slip rates (both seismic and aseismic) can substantially reduce the uncertainty in seismic hazard estimates.
Nonlinear earthquake location: Theory and examples
Authors: Thurber Clifford H.
Published: July 2021

A fundamental modification to Geiger's method of earthquake location for local earthquakes is described which incorporates nonlinear behavior of travel time as a function of source position. The use of Newton's method rather than the usual Gauss-Newton method allows the inclusion of second-order partial derivatives of travel time with respect to source coordinates in the location algorithm. These second-order derivatives can be calculated quite easily for half-space and layered crustal models. Expected benefits are improved convergence and stability, as demonstrated in a series of examples, and more realistic assessment of solution uncertainty.
El principio de capacidad económica en una encrucijada: (la problemática interpretación jurisprudencial del art. 31.1 de la Constitución en el impuesto sobre plusvalías inmobiliarias)
Authors: Rodríguez Bereijo Álvaro
Published: July 2021

El trabajo analiza la problemática conexión entre el art. 31.1 de la Constitución, que establece la obligatoriedad de contribuir al sostenimiento de los gastos públicos desde los principios de igualdad y progresividad, y el impuesto sobre plusvalías inmobiliarias.
Recurso de amparo y recurso de casación contencioso-administrativo: el agotamiento de la vía judicial previa tras su objetivación
Authors: García Couso Susana
Published: July 2021

El trabajo tiene por objeto el estudio de la jurisprudencia del Tribunal Constitucional sobre el requisito del agotamiento de la vía judicial previa al recurso de amparo tras la reforma operada en el recurso de casación contencioso-administrativo por la Ley Orgánica 7/2015, de 21 de julio. Como ha apreciado el propio TC, el cambio sufrido como consecuencia de su objetivación, al incluir el requisito del «interés casacional objetivo para la formación de jurisprudencia» para su admisión, tiene una «indudable repercusión» en la satisfacción del citado requisito procesal.
AĞIR TERATOSPERMİYE BAĞLI ERKEK İNFERTİLİTESİNDE İNTRASİTOPLAZMİK SPERM ENJEKSİYONU-EMBRİYO TRANSFERİ SONRASI GEBELİK SONUÇLARININ DEĞERLENDİRİLMESİ
Authors: Aktaş Hatice , Şık Bulat Aytek , Aba Yılda Arzu
Published: July 2021

AMAÇ: Normal sperm morfolojisi %0 olan erkek infertilitesine sahip hastalarla normal sperm morfolojisi %1 - 4 olan erkek infertilitesine sahip hastaların, intrastoplazmik sperm enjeksiyonu (ICSI) - embriyo transferi (ET) sonrası gebelik sonuçları bakımından karşılaştırılması amaçlanmıştır.GEREÇ VE YÖNTEM: Erkek infertilitesinde önemli bir yer tutan ağır teratozoosperminin ICSI sonuçları üzerine etkisi araştırılmıştır. Kruger strict kriterlerine göre spermiyogramda normal morfoloji oranı %0 olan hastalar ile %1 - 4 olan hasta hastalar, elde edilen MII oosit sayısı, fertilize oosit sayısı, transfer edilen embriyo sayısı, implante olan embriyo sayısı, fertilizasyon oranı ve klinik gebelik oranları bakımından karşılaştırıldı. Gruplar arası dengeyi sağlamak amacı ile 38 yaş üstü, düşük over rezervine sahip, polikistik over sendromu olan kadın hastalar ile azospermisi olan veya total immotil sperm tanısı almış erkek hastalar çalışmaya dahil edilmedi.BULGULAR: İki hasta grubu arasında; ortalama yaş, ortalama infertilite süresi, ortalama vücut kitle indeksi, infertilite tipi, infertilite nedeni, sigara içiciliği, alkol kullanımı, erkek hastalarda geçirilmiş cerrahi, bazal hormon seviyeleri ve antral folikül sayısı bakımından istatistiksel olarak anlamlı bir fark yoktu (p>0,05). İki grupta elde edilen total oosit sayısı, MII oosit sayısı, fertilize oosit sayısı, fertilizasyon oranı ve transfer edilen embriyo sayısı açısından da istatistiksel olarak anlamlı derecede bir fark bulunamamıştır. Morfoloji %0 ve Morfoloji %1 - 4 gruplarının gebelik sonuçları arasında istatistiksel farklılık gözlenmemiştir (p=0,824), (p=0,854), (p=0.216), (p=0,812).SONUÇ: Sperm morfolojisinin, ICSI-ET sikluslarında, fertilizasyon oranları, klinik gebelik oranları ve canlı doğum oranlarına etkisi gözlenmemiştir.
ARDIŞIK TORAKS VE ABDOMEN BT TETKİKLERİNDE TARAMA UZUNLUĞU VE RADYASYON DOZ PARAMETRELERİNİN KARŞILAŞTIRILMASI
Authors: Atlı Eray , Kılınçer Abidin , Uyanık Sadık , Öğüşlü Umut , Çevik Halime
Published: July 2021

AMAÇ: Bu çalışma ile amacımız ardışık toraks ve abdomen BT tetkiklerinde tarama uzunluğu değişkenliğini ve tarama uzunluğunun radyasyon dozu parametreleri üzerine etkisini değerlendirmektir.GEREÇ VE YÖNTEM: Merkezimizde, Ocak 2018 ve Aralık 2018 tarihleri arasında aynı hastaya ait ardışık toraks (n=85) ve abdomen BT (n=57) tetkikleri çalışmaya dahil edildi. Toraks BT tetkiklerinin % 39 (n=33)'u, abdomen BT tetkiklerinin % 51 (n=29)'i kadındı. BT radyasyon dozu parametreleri görüntü arşivleme iletişim sisteminden (picture archiving communications system, PACS) retrospektif elde edildi. Hacimsel BT doz indeksi (Volume CT dose index, CTDIvol) ve doz uzunluk çarpımı (dose length product, DLP) değerleri hasta protokolünden kaydedildi. Etkin doz (ED) ve tarama uzunluğu (TU) hesaplandı. Ardışık toraks ve abdomen BT tetkikleri kendi içinde (ilk tetkik ve ikinci tetkik olmak üzere) iki gruba ayrıldı, ve BT radyasyon dozu parametreleri ile TU değerlendirildi.BULGULAR: Toraks ve abdomen BT'si elde edilen hastaların ortalama yaşı sırasıyla 58±16 ve 51±16'dır. Her iki tetkik bölgesinde ardışık BT tetkikleri arasında DLP ve ED değerleri arasında istatiksel fark saptanmadı (p>0,05). Ardışık tetkikler arasında CTDIvol değeri açısından toraks BT grubunda anlamlı fark bulunmazken (p=0,724), abdomen BT grubunda anlamlı fark göstermektedir (P=0,042). Tarama uzunluğunun tetkikler arasındaki ortalama farkı toraks BT için 3,3 ± 2,6 cm, abdomen BT için 3,1 ± 2,5 cm olarak hesaplandı. Her iki tetkik bölgesinde tarama uzunluğu ardışık tetkikler arasında anlamlı farklılık göstermemektedir (p>0,05).SONUÇ: Ardışık toraks ve abdomen BT tetkiklerinde, tarama uzunluğu açısından DLP ve ED'ye etki edecek bir farklılık saptanmadı. Ardışık tetkiklerde TU açısından fark saptanmamasına rağmen, BT çekimlerinde TU taranan anatomik bölgede tanısal bilgi kaybına neden olmayacak en kısa şekilde ayarlanmalıdır.
THE EVALUATION OF DEPRESSION AND SOCIAL ANXIETY AMONG CHILDREN WITH CELIAC DISEASE
Authors: Bükülmez Ayşegül , Oflu Ayşe Tolunay , İçiğen Erdem , Molon Lütfi , Koca Tuğba
Published: July 2021

OBJECTIVE: Depression and anxiety levels adult patients with celiac disease (CD) have been investigated and conflicting results have been reported. However, there are limited studies on the association of CD with depression and anxiety in pediatric patients. The aim of this study was to investigate the presence of a tendency toward depression and social anxiety in children with CD.MATERIAL AND METHODS: Patients aged between 8-14 years old and who had a gluten-free diet for at least one year and healthy controls within the same age group were included in this study. All participants were administered the Children Depression Inventory (CDI) and Social Anxiety Scale-Revised (SASC-R). 45 children with celiac disease and 45 healthy children were included in this study.RESULTS: The mean age of the experimental group was 11.6 ± 2.4 years old and 76% were female. The mean age of the control group was 12,0±2.1 years old and 62% were female. No significant differences were found between children with CD and healthy controls in terms of CDI and SASC-R scores. Anxiety levels of the patients whose adherence to the diet was good were found to be higher.CONCLUSIONS: This study showed that the incidences of depression and social anxiety were not different from healthy children as similar to previous studies in children with CD.
MÉDICA DA (E NA) FLORESTA: A TRAJETÓRIA DE UMA PARTEIRA, PAJÉ E BENZEDEIRA TEMBÉ TENETHERAR
Authors: Pantoja Ana Lídia Nauar
Published: July 2021

A proposta deste artigo é fazer uma reflexão sobre a importância dos saberes tradicionais e práticas de curas tradicionais entre os povos indígenas Tembé Tenethehar, Nordeste do estado do Pará, por meio das narrativas biográficas de uma parteira, pajé e benzedeira da Aldeia Ytuaçu. A pesquisa de caráter exploratória com utilização do método biográfico e história oral, teve os dados submetidos à análise qualitativa, apontando para a importância que as mulheres assumem na comunidade e em particular a parteira Francisca, cuja trajetória revela a tradição de uma medicina popular que nem sempre é valorizada no contexto das políticas de atenção à saúde indígena que vêm sendo implementadas pelo Estado no local, apontando, com isso, para os riscos de desenraizamentos de valores culturais ancestrais essenciais à preservação das suas tradições e identidades.
A BIBLIOTECA COMO ESPAÇO DE EDUCAÇÃO: O LETRAMENTO DE JOVENS E ADULTOS – PROJETO “ALFABETIZAR PARA LIBERTAR”
Authors: Brito Camila de Cássia , Ribeiro Karley dos Reis , Neves Joana D'Arc de Vasconcelos
Published: July 2021

O presente estudo se constrói numa realidade amazônica marajoara, partindo da realização do Projeto de extensão “Alfabetizar para Libertar”, da Biblioteca Professor Ricardo Teixeira de Barros, do Campus Universitário do Marajó – Soure (UFPA), que propôs desenvolver a leitura como ação alfabetizadora para Jovens e Adultos afastados do cotidiano escolar. A leitura pode ser compreendida como técnica de aperfeiçoamento da capacidade cognitiva do indivíduo, sendo trabalhada com base na cultura, cotidiano, memórias e vivências e experiências individuais e coletivas. Teoricamente, este estudo se baseia nas ideias de Freire (1987,1989,1996,1997); Schwartz (2010); Leal; Albuquerque e Morais (2010), Giubilei (2005); Leite (2013) e Gadotti; Romao (2011). Por conseguinte, utilizam-se como técnicas de coleta de dados o questionário e a observação caracterizando este estudo como pesquisa- ação. Os resultados identificam que dos 27 participantes do projeto, 25 destes aperfeiçoaram seus conhecimentos de leitura aliada a prática da escrita e 2 daqueles, aprenderam a ler e a escrever. Toda ação praticada em prol da comunidade possui suma importância para o campo cientifico educacional como um todo e projetos de extensão em espaços educativos diferenciados, são bem vindos como prática de integração da Universidade com a comunidade acadêmica e externa proporcionando experiências significativas na vida desses indivíduos.
CANTOS E GRITOS DA TERRA: CAMPESINOS E PROPRIETÁRIOS RURAIS NOS PROCESSOS DE REFORMA E CONTRARREFORMA AGRÁRIA DO CHILE (1958-1990)
Authors: Ribeiro Vanderlei Vazelesk
Published: July 2021

Neste trabalho discute-se o processo de reforma e contrarreforma agrária, ocorrido no Chile entre as décadas de 1960 e 1990. Reflete-se, inicialmente, a respeito do processo de reforma agrária desenvolvido durante as presidências de Jorge Alessandri (1958-1964), Eduardo Frei (1964-1970) e Salvador Allende (1970-1973). Posteriormente, avalia-se o esforço de reversão do processo executado durante o regime liderado pelo general Augusto Pinochet entre 1973 e 1990. Entende-se estes processos como resultado da interação entre a burocracia de Estado e os diversos grupos sociais. Deste modo, analisa-se “a atuação tanto de organizações representativas dos proprietários de terra como dos movimentos campesinos.” Procuraremos perceber estes movimentos não como todos homogêneos, mas observando suas divergências internas, que levam, às vezes, a fraturas intraorganizacionais. Quando possível realiza-se a comparação do desenvolvimento da reforma e da contrarreforma, cotejando seu desenrolar no Chile central e na Região Sul, marcada pelos conflitos entre os terratenentes e as populações mapuches, na luta pela posse da terra. Deste modo, compreende-se o peso do tema indígena nesta região, que teria reflexos no contexto nacional.
Editorial
Authors: Steward Angela May , Barros Flávio Bezerra , Guerra Gutemberg Armando Diniz , De Assis William Santos
Published: July 2021

.
Zarządzanie talentami a orientacja na uczenie się przedsiębiorstw
Authors: Skuza Agnieszka
Published: July 2021

Zasadniczym celem pracy jest ustalenie wpływu zarządzania talentami na orientację na uczenie się przedsiębiorstw. Jego realizacja wymagała opracowania spójnych koncepcji obu zagadnień oraz ich empirycznej weryfikacji. Autorka ocenia programy i procesy zarządzania talentami w Polsce, zajmuje się problemem modelowania organizacji uczącej się oraz przedstawia wyniki swoich badań.
The Forms of Expression Of Society Virtualization as a Post-Historical Phenomenon (Ukrainian Aspect)
Authors: OKOROKOVA Vira
Published: July 2021

The article aims to study of one of the relevant issues in the field of the modern post-history, namely, the virtualization of society. The latter is considered as a result of the postmodern worldview and the simulative nature of knowledge about social reality. The subject of the research involves the forms of virtual culture reflected in today’s Ukrainian society. Given the specifics of the identified issue, the author of the article draws attention to the specific methodological apparatus of the research. The narrative background of the research, as well as the principle of historicism, allows one to consider virtualization as a process of modelling social reality using computer technologies, whose image or prototype is a historical reality. It is important to note that the virtualization of society has a historical conditionality, which makes it possible to consider it as the next stage of the historical and cultural development of society. At the same time, the modern type of culture is a virtual culture, whose main creator and consumer is human. Its main feature is a pronounced innovative character. The main forms of Ukrainian society virtualization are focused on virtual communities and virtual states. Importantly, each of them mimics the social reality, whose prototype is an image characterizing the cultural identity of society.
Distance Learning for a Foreign Language in the Postmodern Age and its Forms
Authors: STEZHKO Yurii , GRYTSYK Nadiia , MYKHAILIUK Maryna , TEKLIUK Hanna , RUSAVSKA Olha , BEREGOVA Olga
Published: July 2021

The article is devoted to innovative postmodern requests for the liberalization of education. Postmodernism influenced education not only methodologically, but also by changing the very pedagogical culture of teaching. Now the relevance of the research topic is due to the problems of forming information content and methodological support for the introduction of distance learning technology in mobile form. The introduction of IT in education, the improvement of smart devices, the formation of an electronic information and educational environment have created the basis for such forms of education as mobile learning and blended learning. In both cases, the student situationally himself forms the educational process, turns from an object of training into its subject. The humanistic potential of mobile learning in the sense of ensuring equal access to education for people with different abilities is noted. The opinion is expressed about the importance of student motivation and IT competence of teachers to provide information content, intensify the introduction of e-learning and mobile-oriented learning technologies. It is argued that learning based only on mobile learning technology, using smart devices without classroom or office work, real communication with the teacher is not didactically self-sufficient, which would provide adequate language skills. Effectiveness in learning foreign languages is achieved by synergy of technologies distance mobile and traditional classroom or classroom training, real communication with the teacher.