bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accuracy in LP electromagnetic seismograph calibration by least-squares inversion of the calibration pulse
Authors: McGonigle Robert W. , Burton Paul W. 
Published: June 2021

abstractUncertainties in the instrumental constants for the standard LP instruments of the WWSSN, arising from errors in amplitude measurements of the calibration pulse, are analytically quantified assuming that such measurement errors may be approximated by a perturbing Gaussian noise distribution. More importantly, for the practicing seismologist, uncertainties in magnification and phase delay of the entire instrumental transfer function are deduced from least-squares inversion of the seismogram calibration pulse. It is emphasized that reliable estimates of instrumental transfer functions are obtained by least-squares inversion of the calibration pulse, particularly for underdamped or near critically damped seismographs, where the Gaussian noise distribution is the dominant source of error.
Near-field Rayleigh waves from surface explosions
Authors: Murphy John R. 
Published: June 2021

abstractThe low-frequency components of the near-field ground motions produced by surface explosions are investigated and evidence is presented which suggests that much of this motion can be accounted for by the Rayleigh waves induced by the airblast loading acting on the surface exterior to the region of strong nonlinear response (i.e., the crater). Scaling laws are derived for this component of the motion which indicate that the amplitude of the Rayleigh wave source function is expected to be directly proportional to yield and independent of site geology at low frequencies and to scale as yield to the one-third power and increase with the near-surface shear wave velocity at high frequencies. Finally, an unusual arrival recorded interior to a hexagonal array of surface explosions is analyzed and shown to be consistent with Rayleigh waves converging on the center from an exterior, axisymmetric, surface-ring load which may correlate physically with the multi-burst spall closure for this event.
Strong ground motion of mine tremors: Some implications for near-source ground motion parameters
Authors: McGarr A. , Green R. W. E. , Spottiswoode S. M. 
Published: June 2021

abstractGround acceleration was recorded at a depth of about 3 km in the East Rand Proprietary Mines, South Africa, for tremors with −1 ≦ ML ≦ 2.6 in the hypocentral distance range 50 m &lt; R ≦ 1.6 km. The accelerograms typically had predominant frequencies of several hundred Hertz and peak accelerations, a, as high as 12 g. The peak accelerations show a dependence on magnitude, especially when expressed as dynamic shear-stress differences, defined as σ˜ = ρRa, where ρ is density. For the mine tremors, σ˜ varies from 2 to 500 bars and depends on magnitude according to log σ˜ = 1.40 + 0.38 · ML. Accelerograms for 12 events were digitized and then processed to determine velocity and, for seven events with especially good S/N, displacement and seismic source parameters. Peak ground velocities v ranged up to 6 cm/sec and show a well-defined dependence one earthquake size as measured by ML or by seismic moment, Mo. On the basis of regression fits to the mine data, with −0.76 ≦ ML ≦ 1.45, log Rv = 3.95 + 0.57 ML, where Rv is in cm2/sec, and log Rv = −4.68 + 0.49 log Mo. These regression lines agree excellently with the corresponding data for earthquakes of ML up to 6.4 or Mo to 1.4 × 1026 dyne-cm. At a given value of ML or Mo, a, at fixed R, shows considerably greater variation than v and appears to depend on the bandwidth of the recording system. The peak acceleration at small hypocentral distances is broadly consistent with ρRa = 1.14 Δτrofs/β, where Δτ is stress drop, ro is the source radius, β is shear velocity, and fs is the bandwidth of the recording system. The peak velocity data agree well with Rv = 0.57 βΔτro/μ, where μ is the modulus of rigidity; both expressions follow from Brune's model of the seismic source and were compared with data for events in the size range 5 × 1016 ≦ Mo ≦ 1.4 × 1026 dyne-cm. Measurements of the source parameters indicated that, as for earthquakes, the stress drops for the tremors range from 1 to 100 bars and show no consistent dependence on Mo down to Mo = 5 × 1016 dyne-cm.
A comparative seismic hazard study for Azerbaijan Province in Iran
Authors: Rowshandel B. , Nemat-Nasser S. , Corotis R. B. 
Published: June 2021

abstractDifferent seismic source models are used to estimate regional seismic hazard. Commonly used point, line, and area seismic sources are considered in addition to a new method which is obtained by modifying the line source model to take into account the uncertainty associated with the exact location of the line (i.e., fault). The results are presented in terms of cumulative functions of peak ground acceleration for major sites in the Azerbaijan Province of northwest Iran. Iso-acceleration maps for two different return periods are also developed for each seismic source model and a comparison is made among the results of the models.The point source model is shown to be unrealistic when used to model large shocks (Ms &gt; 6.5), which correspond to long ruptures. The model cannot incorporate the fault length, thus ignoring possible spatial migration of seismicity along the fault. In addition, the actual attenuation of ground motion departs considerably from that associated with point source assumption.The conventional line source model, while providing a good representation of vertical strike-slip faults, cannot accurately model the seismicity in other cases, such as reverse faults in general, and thrust (low angle reverse) faults in particular. Epicenters for these latter cases do not lie along a line, as they do in case of vertical strike-slip faults.The area source model is used for those cases where the distribution of earthquake epicenters in a region does not follow any identifiable geological fault pattern. The spatial migration of seismicity along an active fault during a given exposure time is of vital importance in seismic hazard analysis. An analysis based on an area source model corresponds to assuming this migration will be equal in all directions. The theory of plate tectonics, however, suggests an elongated narrow zone corresponding to each fault.A fault line model is developed which exhibits less sensitivity of near-field ground motion to precise fault location than the line source model. This model is referred to as the strip source model. According to this model, the seismicity on a fault is spatially distributed in a long and narrow zone along the margins of the corresponding plates or microplates, and decreases with distance from the fault on either side. It is believed that this kind of modeling closely represents the seismicity corresponding to interplate earthquakes, especially when the type of faulting is thrust. Uncertainties due to the location and orientation of faults will be considerable, particularly for the buried faults, and these uncertainties can be incorporated in the strip source model.
Approximate method to estimate the short-period strong motion spectra on bedrock
Authors: Ishida Katsuhiko 
Published: June 2021

abstractThe methodology to estimate the strong motion Fourier amplitude spectra in a short-period range (T ≦ 1 to 2 sec) on a bedrock level is discussed in this paper. The basic idea is that the synthetic strong motion Fourier spectrum F˜A(ω) calculated from smoothed rupture velocity model (Savage, 1972) is approximately similar to that of low-pass-filtered strong earthquake ground motion at a site in a period range T ≧ 1 to 2 sec: F˜A(ω)=B˜(ω)·A(ω). B˜(ω) is an observed Fourier spectrum on a bedrock level and A(ω) is a low-pass filter. As a low-pass filter, the following relation,A ( T ) = · a · T n a T n + 1 , ( T = 2 π / ω ) ,is assumed. In order to estimate the characteristic coefficients {n} and {a}, the Tokachi-Oki earthquake (1968), the Parkfield earthquake (1966), and the Matsushiro earthquake swarm (1966) were analyzed. The results obtained indicate that: (1) the coefficient {n} is nearly two for three earthquakes, and {a} is nearly one for the Tokachi-Oki earthquake, eight for the Parkfield earthquake, and four for the Matsushiro earthquake swarm, respectively; (2) the coefficient {a} is related with stress drop Δσ as (a = 0.07.Δσ). Using this relationship between {a} and Δσ, the coefficients {a} of past large earthquakes were estimated.The Fourier amplitude spectra on a bedrock level are also estimated using an inverse filtering method of A ( T ) = a T 2 a T 2 + 1 .
The corner frequency shift, earthquake source models, andQ
Authors: Hanks Thomas C. 
Published: June 2021

abstractThe very common seismological observation that the P waveform is enriched in high-frequency motion relative to the S waveforms of the same earthquake manifests itself, in spectral studies of the earthquake mechanism, as the “corner frequency shift,” the general although not ubiquitous tendency for the P-wave corner frequency fo(P) to be greater than the S-wave corner frequency fo(S). In point source, time-domain modeling studies of the earthquake mechanism which follow the recipe of D. V. Helmberger and C. A. Langston that explicitly suppresses the corner frequency shift, it is an equally common result that the synthetic S waves are systematically enriched in high-frequency motion relative to the observations. Almost three dozen spectral analysis and time-domain modeling studies are recapitulated in this one to conclude: (1) the corner frequency shift is a very common condition of the far-field body waves of earthquakes, with no discernible dependence on earthquake source strength, hypocentral distance or depth, or recording device; and (2) the corner frequency shift is the manifestation of an intrinsic property of earthquakes, source finiteness. Anelastic attenuation estimates for shear waves determined on the basis of a source model derived from P waves are likely to be strongly biased to high values of Q-1, if the shear excitation is estimated directly from the equivalent far-field compressional excitation, i.e., with no allowance for source finiteness. The corner frequency shift, moreover, places strong constraints on admissible earthquake source models; point-source and Haskell-type dislocation models will not be among them.
Analysis of split normal modes for the 1977 Indonesian earthquake
Authors: Stein Seth , Nunn Jeffrey A. 
Published: June 2021

abstractThe longest period spheroidal mode multiplets, 0S2 to 0S5, are well recorded on IDA gravimeter records of the 19 August 1977 (Ms734) Indonesian earthquake. We model these modes, which are split into singlets by rotation and ellipticity, using time domain synthetics which reproduce the complex interference pattern between the various singlets in each multiplet. This method, developed to fit a single strainmeter record of the Chilean earthquake, successfully fits records at multiple stations using a common source. We also study the attenuation of the split modes by matching the decay of multiplet envelopes and individual singlets.
Tphases from underwater explosions off the coast of Israel
Authors: Shapira Avi 
Published: June 2021

abstractT phases from underwater explosions off the coast of Israel were recorded at three temporarily installed seismograph stations. The T waves propagated as sound waves through the water with a velocity of about 1.53 km/sec, possibly in the so-called SOFAR channel. Three phases, constituting T, have been identified. These were traveling along the land path as P, S, and/or surface waves, with velocities of 2.5 km/sec and lower. Analysis of the maximum amplitudes and the durations of these phases, indicate low Q values for the material along the land path of the T phases. The quality factor, Q, of the sea water seems to be more than 10 times higher than that of the land. Relatively high scattering in the measured travel times, amplitudes, and durations reflect the structural and geological complexity of the region.
Review of seismic source models for underground nuclear explosions
Authors: Massé Robert P. 
Published: June 2021

abstractA number of seismic source models for underground nuclear explosions have been developed over the past 2 decades. These models include the spherically symmetric compressional source model, the wave conversion source model, the tectonic strain release source model, the spall slapdown source model, and the near-regional source model. These model are reviewed in this study and are shown to be inconsistent with various geophysical data associated with underground nuclear explosions. In particular, the Rayleigh and Love wave signals generated by underground nuclear explosions have not been explained satisfactorily by any of these source models. To explain the observed explosion data, it may be necessary to model the explosion seismic source as a sequence of mechanisms producing seismic signals. These mechanisms all act within the first few seconds following the explosion detonation. One of the most important of these mechanisms is probably explosion-induced thrust faulting.
The Chelmsford-Lowell, Massachusetts, earthquake of 23 November 1980: Depth control and fault plane solution
Authors: Pulli Jay J. , Guenette Michael J. 
Published: June 2021

abstract
On 23 November 1980, a small (magnitude 2.9) earthquake occurred on the Chelmsford-Lowell, Massachusetts, border, approximately 10 km northeast of the MIT seismic station at Westford, Massachusetts (WFM). Thus we were able to accurately determine the focal depth, which is generally not the case in New England. Our hypocentral solution was latitude 41.63, longitude −71.36, depth 1.5 km, at origin time 00:39:32.0 UTC. The fault plane solution shows either strike-slip or dip-slip faulting with a P axis trending NE-SW, which is in agreement with overcoring measurements in a nearby granite quarry.
On the saturation of earthquake magnitudes
Authors: Howell B. F. 
Published: June 2021

abstractAs MS, mb, or unified magnitude approaches 8, there is an abrupt change in the rate at which frequency of occurrence decreases with magnitude. This change is not observed for moment-magnitude, MW. Data on past earthquakes are insufficient to prove whether there is a finite upper limit on MS, mb, or unified magnitude or whether earthquake probability is better described by an unlimited logarithmic relation of the formM = E + F ( I n ( G − I n ( − I n probability ) ) ) .This empirical equation, however, fits the world data best.If there is an upper limit on size, it is approximately 8.1 for mb, 8.7 for MS, and 8.9 for unified magnitude.For regions such as the contiguous United States and Alaska, there are too few large earthquakes for saturation to be clearly observed, but the data at large magnitudes fit an empirical equation of shapeM = A + ( M max − A ) tanh ( C X − D )better than either the Gumbel I or III theory. This equation provides for a more sudden saturation than Gumbel's theory allows.
Consequence of an earthquake prediction on statistical estimates of seismic risk
Authors: Anderson John G. 
Published: June 2021

abstractThis paper formulates a procedure for estimating the consequence of an earthquake prediction on statistical estimates of seismic risk. Several examples, using this procedure, indicate the following general conclusions: if a prediction with a confidence level of 1.0 significantly affects the risk at a site, then the same prediction at smaller confidence levels will also affect the risk. If an earthquake is predicted in a high risk zone, it can be important for an entire adjacent low risk zone; a prediction for the adjacent low risk zone may not affect the high risk zone at all. Finally, a prediction for a region which may significantly affect the amplitudes of shaking that can be expected in the next year may have no importance for structures which are designed (or planned) with a 50 or more year lifetime, depending on the size of the predicted earthquakes.These conclusions are drawn from a hypothetical, yet plausible, case study in the Los Angeles, California, region, where hypothetical predictions are considered for events on the San Andreas fault, the Sierra Madre fault, and a region of about 4300 km2 covering the most populated region of the Los Angeles basin. For the background seismicity model used in this study, the threshold of a significant (to the seismic risk) prediction for 1-yr risk is M = 5 on the San Andreas fault, M = 412 on the Sierra Madre fault, and M = 4 in the Los Angeles zone. For the 50-yr risk, the thresholds of significance are M = 7, M = 612, and M = 6, respectively, for the same three zones.
Pregnancy outcome study between Pradhan mantri surakshit matriva abhiyan service utilization group and pradhan mantri surakshit matriva abhiyan service non-utilization group: a comparative study
Authors: Mandal Purnima , Mandal Jaydeb 
Published: June 2021

Background: Safe pregnancy has become a social movement in our country. Almost 15 % of all pregnant women can develop potentially life-threatening complications. As a result, identification of high-risk pregnancies at earliest stage will be useful in directing appropriate intervention. Hence this study was done to evaluate the betterment of pregnancy outcome of the women who had taken the adequate service of Pradhan Mantri Surakshit Matriva Abhijyan service (PMSMA) than who had not.Method: A longitudinal study was conducted at Malda medical college during January 2019 to June 2019. 385 women selected who had taken at least three antenatal checkups (from record analysis) at PMSMA designated clinic and another 385 women selected who had not taken PMSMA services. Women of both groups were followed up their delivery events and puerperal days till discharge from hospital. Pregnancy outcomes were compared and statistical analysis of both groups were done by SSPS software. Results: A significant outcome difference of PMSMA service utilized and non-utilized groups in respect to fetal and maternal parameters including moderate to severe anemia, (12.98% vs 26.49%), intra uterine growth retardation (IUGR, 20.0% vs 29.87%), hypertensive disorders in pregnancy (HDP, 8.31% vs 13.50%), low-birth-weight (21.30% vs 31.16%) and stillborn (1.29% vs 2.89%) were observed.Conclusions: This study showed positive pregnancy outcome of PMSMA utilized group than non-utilized group. Improving the availability and accessibility of quality antenatal and delivery care through PMSMA services in all our institutions, will improve pregnancy outcome.
Analyzing the most effective indicators of accountant professional ethics: the inevitable necessity for assessing the safe behavior of accountants
Authors: Mir Hosseini M , Moinuddin M , Hirani F , Hatami Nasab SH 
Published: June 2021

Introduction: Morality is very important in human life because human humanity is formed when moral values are crystallized in him. Every human being is evaluated to the extent of the emergence of moral values in thoughts, speech, and behavior, the first manifestation of a person in society is that person's morality. To increase the impact of professional ethics, it is necessary to have patterns that are consistent with culture and society, and by recognizing them, the dimensions of safe behavior by accountants can be explored.
Materials and Methods: This research is based on a combined method. Because in this research, both quantitative and qualitative approaches have been used in data collection and analysis, a combination of findings and conclusions. In the present study, data collection has been done through library and field research methods. Statistics consists of theoretical texts related to accounting professional ethics. In this study, using a researcher-made questionnaire, effective criteria based on previous research were identified and finally, 25 sub-components in the form of 5 indicators were identified as the most important factors of professional ethics. In this study, NVIVO software (in the content analysis section) Used.
Results: According to experts, the components of professionalism and organization are more important than other criteria and affect the sustainable development of safe behavior and professional ethics of the accountant.
Conclusion: By understanding the professional ethics of accountants and identifying its basic components in different dimensions and determining the importance of each of them, a specific framework or format for accountants to observe or not to observe professional ethics and the desire to act based on Design and implement a code of professional conduct to reduce unsafe behaviors and, as a result, reduce the incidence of accidents in the country's industries.
SECTARIAN WAR IN THE MIDDLE EAST: IRAN, SAUDI ARABIA, PAKISTAN AND AN UNENDING WAR FOR REGIONAL HEGEMONY
Authors: Faheem Farrukh , Hussain Sajjad , Xingang Wang 
Published: June 2021

Purpose: This paper aims to explore the current chaotic condition of the Middle East that was fueled by the traditional competition between Saudi Arabia and Iran. s state and society in every field of life.
Principal Findings: The paper argues that the Saudi-Iran’s sectarian proxy warfare in the Middle East is a means to counter each other’s regional influence that has adverse implications for the internal security of Pakistan that can destroy its economy as well.
Methodology: This research is based on a qualitative approach and deductive method. The paper answers four main queries: To what extent the Iran–Saudi Rivalry a result of sectarian aspirations? How are both countries using proxy warfare methods in the region to realize their interests vis a vis each other? What is the role of external powers like the United States or Russia in proxy warfare? How does the competition between Iran and Saudi Arabia impact Pakistan?
Applications: The study concludes that the outcome of the predicament in the Middle East has produced policy challenges for Pakistan vis-à- vis its relations with Saudi Arabia and Iran. The growing threats of sectarianism, violent extremism, domestic Polarization, and danger to the economic development of Pakistan make it an important player in this competition.
Novelty: The traditional Conflict between Saudi and Iran affects the entire region of the Middle East. Sectarianism is one of the serious concerns of all Muslim countries today. It truly has both internal and external sources in other neighbouring Muslim states. Thus, this research provides an understanding to comprehend Pakistan’s internal and as well as external problems.