bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maximum vertical ground displacement of seismic waves generated by explosive blasts
Authors: Willis David E. , Wilson James T. 
Published: July 2021

ABSTRACT
An approximate first-power relationship was found between the maximum vertical component of ground displacement and the charge size from a number of quarry shots. The maximum vertical ground displacement, normalized to the Rainier (1.7 kt.) underground nuclear shot, is presented for a series of explosive shots ranging in size from 1 ton 19 kilotons and at distances of 1 to nearly 1,000 kilometers. The following empirical equations were found to fit the observed data:A=0.65±0.15R3/2from1to100kilometersA=(0.013±0.003)e−(0.0072±0.0003)RR1/2from100to1,000kilometers where A is the maximum vertical component of ground displacement in centimeters and R is the distance in kilometers.
An integral solution of the electromagnetic seismograph equation
Authors: Ingram R. E. 
Published: July 2021

ABSTRACT
In investigating the response of an electromagnetic seismograph to various ground movements it is advantageous to have the solution of the differential equation as an integral. This is done by finding the Green's function, f(s), for the particular instrument. The angular movement of the galvanometer is then θ(t)=q∫0tf(s)x″(t−s)ds where x(t) is the ground movement and prime stands for the operator d/dt. It is sufficient to find one function, F(s), with dF/ds = f(s), to give the response to a displacement test, a tapping test, or a ground movement.
Report on some experimental long-period seismographs
Authors: Gilman Ralph 
Published: July 2021

ABSTRACT
The unexpected usefulness in research of the Press-Ewing seismograph system (Press, Ewing and Lehner, 1958) has stimulated further efforts to obtain even higher seismograph sensitivity in the period range beyond 100 see. A major difficulty has been in maintaining pendulum stability at long periods. This paper describes a stable long-period seismometer and gives results from several seismograph systems incorporating long-period pendulums and galvanometers.
Anisotropy of the rock in the approaches to Halifax Harbour, Nova Scotia
Authors: Macpherson J. D. 
Published: July 2021

ABSTRACTDuring the summer of 1959 a series of high resolution acoustic refraction profiles were obtained for the Hartlen Point region of the Scotian Shelf. The profiles were taken across pairs of the three bottomed barium titanate hydrophones, connected by cables to a laboratory on the shore. The fixed positions of these hydrophones enabled the bottom properties to be measured considerably more accurately than is normally possible in water-covered areas. Marked anisotropic effects in the rock bottom were found by the surveys.
S waves: Alaska and other earthquakes
Authors: Stauder William 
Published: July 2021

ABSTRACT
Techniques of S wave analysis are used to investigate the focal mechanism of four earthquakes. In all cases the results of the S wave analysis agree with previously determined P wave solutions and conform to a dipole with moment or single couple as the point model of the focus. Further, the data from S waves select one of the two nodal planes of P as the fault plane. Small errors in the determination of the angle of polarization of S are shown to result in scatter in the data of a peculiar character which might lead to misinterpretation. The same methods of analysis which in the present instances show excellent agreement with a dipole with moment source are the methods which in a previous paper required a single force type mechanism for a different group of earthquakes.
The effect of boundaries on wave propagation in a liquid-filled porous solid
Authors: Deresiewicz H. 
Published: July 2021

ABSTRACT
A general solution is deduced of the differential equations which describe the propagation of elastic waves in a nondissipative liquid-filled porous solid. The solution is then used to examine some of the phenomena which arise when each of the three body waves predicted by the field equations is, in turn, incident on a plane traction-free boundary. It is found, for example, that an obliquely incident wave of each type in general gives rise to reflected waves of all three types.
On the long period character of shear waves
Authors: Oliver Jack 
Published: July 2021

Abstract
S and multiple S phases at moderate to large epicentral distances are frequently followed by normally-dispersed, long-period, wave trains for which surface particle motion is elliptical and progressive and in the plane of propagation of the SV wave. The character of such phases can be explained as the result of coupling between the incident shear waves and dispersive PL waves in the near-surface wave guide. A detailed study of shocks in Mexico and in Montana recorded at Resolute, and less detailed studies of other data support this hypothesis.
Automatic computation of impulse response seismograms of Rayleigh waves for mixed paths
Authors: Aki Keiiti , Nordquist John M. 
Published: July 2021

Abstract
A program has been devised to compute theoretical seismograms of Rayleigh waves for a given epicenter and a given station entirely automatically on an electronic computer.
The earth's surface is divided into three regions; continents, Pacific Ocean, and oceans other than the Pacific. Allowance can be made for differences in structure in these regions. This simple division seems satisfactory at present for Rayleigh waves of periods longer than 35 sec.
Diffraction of elastic waves by the core of the Earth
Authors: Knopoff Leon , Gilbert Freeman 
Published: July 2021

Abstract
The problem of the diffraction of a seismic pulse by the core of the Earth is investigated theoretically. The result is compared to that of diffraction by a half-plane. The differences are striking. Laboratory model experiments have been performed to verify the theoretical approximations in their regions of validity, and to complement the theory elsewhere. The curves, thus obtained, of the theoretical amplitude distribution in the shadow of the Earth's core agree very well with the observations of Gutenberg. It is therefore concluded that diffraction is a completely adequate explanation for the amplitude distribution in the shadow zone.
The effect of boundaries on wave propagation in a liquid-filled porous solid: II. Love waves in a porous layer
Authors: Deresiewicz H. 
Published: July 2021

Abstract
The transcendental equation is derived relating frequency and phase velocity of propagation of Love waves in a porous layer containing a viscous liquid. This equation, being complex, can be satisfied only if the wave number of the motion is complex, indicating that the disturbance is dissipative.
The general expression being intractable analytically, an approximate scheme is employed to determine the phase velocity and measure of dissipation valid for porous materials in which the mass (per unit volume of aggregate) of the interstitial liquid is smaller than that of the solid.
Behavior of window panels under in-plane forces
Authors: Bouwkamp J. G. 
Published: July 2021

Abstract
This paper discusses the results of thirty-nine in-plane loading tests on single window panels under a horizontal in-plane force applied to the horizontal top member of a steel, pin-connected, or hinged, loading frame. Under this load condition the movement of the glass with respect to the sash as well as the horizontal in-plane deflection, or drift, of the window panel, fastened to this hinged frame, were measured by means of dial gages.
Panel size and panel configuration Panel attachment to hinged frame Sash material Clearance between glass and sash Hardness of putty
Thirty-three specimens were tested under static loads. Two tests were performed under repeated reversed loads and four under impact loads.
Some conclusions were derived regarding the ultimate drift of a window panel under the load conditions used and as affected by the variables listed.
Calibration of electromagnetic seismographs satisfying galitzin conditions
Authors: Chakrabarty S. K. , Tandon A. N. 
Published: July 2021

Abstract
A large number of electromagnetic seismographs are now in operation at the different stations of the world network of seismological observatories and valuable data have been collected through them. Various attempts have earlier been made for the precise estimation of the instrumental constants as well as the magnification curves, but such estimations were not precise either due to approximations introduced in the analysis or due to difficulties of precision measurements during the experiments suggested for the determination of some of the instrumental constants.
In the present paper theoretical results have been given for the response of the seismographs to different tests required in the calibration of the electromagnetic seismographs, and also to sinusoidal ground motion. The “reaction of the seismometer and galvanometer” has been retained. Final results have also been given for the special types of seismographs in which the seismometer period and galvanometer period are equal and the galvanometer is critically damped. The variation of the magnification curve as well as that of the response to different tests, with changes in the reaction and seismometer damping, have been obtained. Methods have been indicated by which the instrumental constants can be determined and the seismographs can be adjusted to any prescribed condition. The results of calibration of a Sprengnether seismograph in operation at the Central Seismological Observatory, Shillong have been given. The methods suggested can also be used in the precise estimation of the instrumental constants and the magnification of seismographs of the Galitzin type even in their past operating condition, if the routine test data, particularly the response to tapping test and sudden impulse test are available.
The tsunami of May 23, 1960, on the Island of Hawaii
Authors: Eaton J. P. , Richter D. H. , Ault W. U. 
Published: July 2021

Abstract
The tsunami of May 23, 1960, originating in an area of profound crustal disturbance along the coast of Chile, resulted in the greatest natural disaster in Hawaii since the Aleutian-born tsunami of 1946. A study of T phases from earthquakes produced by this disturbance suggests that the duration of faulting responsible for the largest earthquake and the tsunami was about 7 minutes. With the exception of the Hilo Bay area, wave heights on the Island of Hawaii were generally low, ranging between 3 and 17 feet, and averaging 9 feet. At Hilo, the third wave, which developed into a bore as it entered the bay, rose 35 feet above sea level. The action of this bore is best explained in terms of an hydraulic shock wave; its relation to the tsunami wave train, however, is poorly understood. Patterns of wave heights on Hawaii's shores produced by recent tsunamis of diverse geographic origin are strikingly different, whereas those from nearly the same origin are remarkably similar. The city of Hilo, which experienced a loss of 61 lives and $20 million in property, sustained the most extensive damage that occurred in the Hawaiian Islands. The need for tsunami research and continual public education, as a means for preventing further disaster, is painfully evident. The wave height data presented, together with the fullest possible evaluation of the seismogram, should aid in indicating danger areas and forecasting wave heights in future tsunamis.
Integrated velocity and displacement of strong earthquake ground motion
Authors: Berg G. V. , Housner G. W. 
Published: July 2021

Abstract
The earthquake ground accelerations recorded at El Centro, 30 December 1934; El Centro, 18 May 1940; Olympia, Washington, 13 April 1949; and Taft, California, 21 July 1952, have been integrated with a digital computer to obtain at each location the three components of ground velocity and ground displacement. Maximum horizontal displacements of 10 and 20 inches are indicated, and maximum vertical displacements of 5 inches are indicated.
The effect of variations in layer thickness on Love waves
Authors: de Noyer John 
Published: July 2021

Abstract
A model is considered in which Love waves propagate perpendicular to the trend of a structure that is varying in thickness as a sine function of distance. The period equation for this model is obtained and average values for phase and group velocities are found for several distance ranges. A method is proposed for finding relative amplitudes as a function of position along the structure for any specified period.
The effect of the earth's surface on the S wave particle motion
Authors: Nuttli Otto 
Published: July 2021

Abstract
This paper is concerned with the determination of the particle motion of the earth's surface due to the incidence of a plane S wave of arbitrary polarization and incidence angles. It is assumed that the earth's surface may be represented by a plane surface.
For angles of incidence less than sin-1(b0/a0, where a0 and b0 are the P and S wave velocities at the earth's surface, all three components of ground motion will be in phase, and the resultant motion is linear. For angles of incidence greater than sin-1(b0/a0), all three components of ground motion will in general be out of phase, with the resultant motion describing some three-dimensional figure. The epicentral distance at which the motion changes from linear to non-linear depends upon the wave length of the S wave and the slope of the travel time curve at that distance.
An observational determination of the variation of the angle of incidence of P waves with epicentral distance
Authors: Nuttli Otto , Whitmore John D. 
Published: July 2021

Abstract
Apparent angles of incidence of the P wave were obtained from the seismograms of the Galitzin-Wilip instruments at Florissant. The “half-periods” of these waves varied from 112 to 312 seconds, and the epicentral distances from 16.5° to 103.2°. The data indicate that the velocity of P waves at the earth's surface is approximately 8 km/sec. This suggests that these P waves do not see or are not affected by the earth's crust, although the crustal thickness is known to be approximately 35 km. P wave data from five other stations for the Alaska earthquake of July, 1958 support the conclusions obtained from the Florissant data.
Response of a simple structure to a random earthquake-type disturbance
Authors: Bogdanoff John L. , Goldberg John E. , Bernard M. C. 
Published: July 2021

AbstractA physically plausible second order random function has been selected to represent ground acceleration. Several member functions have been presented in graphical form. Some of the statistical properties of the response of a simple structure to this acceleration have been determined and possible uses of these properties by designers of aseismic structures have been commented upon. Lines for additional investigation of the uses of random function theory in the study of seismic disturbances also have been indicated.
Earthquake insurance in the United States—A reappraisal
Authors: Buffinton P. G. 
Published: July 2021

Abstract
The basic objective of this paper is to inform seismologists of some of the major problems which confront the earthquake insurance underwriter and to point out certain areas which are in need of further research and study.
The basic factors which are generally considered in making fire and other property insurance rates are discussed with special emphasis on their application in the earthquake insurance field.
The most important factor from the standpoint of earthquake insurance is the element of time or frequency of loss occurrence. In this connection a comparison is made of the fire and earthquake loss ratios for the period 1916-1957.
The earthquake experience by geographic zone in the United States is discussed and a table is presented showing the frequency of United States earthquakes for the period 1638 through 1956. The author points out that based on this information, it would appear that earthquake rates in the Northeastern United States should be about 110 of the rates charged in California.
A comparison is also made of the average damage in dollars for earthquakes of various intensities and a table is provided showing the results for earthquakes of intensity 7 and over on the Modified Mercali Scale.
The author concludes that the underwriter would be aided by more detailed information on individual earthquakes including specific information on the type of construction damaged, the type of ground upon which the building has been built, the total dollar damage and the estimate of property values in the high damage areas. Also needed is a further evaluation of the relation of intensity and frequency and better analysis of damage caused by earthquakes of various intensities.
An oscillating system for a long-period seismometer for horizontal motion
Authors: Romberg Frederick E. 
Published: July 2021

Abstract
An oscillating system suitable for use in a long-period horizontal-motion seismometer is described. The system consists of a short vertical pendulum whose gravitational restoring torque is opposed by a vertical zero-length spring. By adjusting the spring constant with respect to the mass of the pendulum the net restoring torque can be reduced to almost zero, thus giving the system a long period. The period is less sensitive to tilt than that of the horizontal pendulums commonly used in seismometers for horizontal motion. The lateral dimensions of the system are small so that it is adaptable for use in a bore hole and for easy transportation and setting up. A stable period of 30 seconds has been observed in a prototype model.
Energies, magnitudes, and amplitudes of seismic waves from quarry blasts at Promontory and Lakeside, Utah
Authors: Berg Joseph W. , Cook Kenneth L. 
Published: July 2021

Abstract
The total apparent energy was computed for seismic waves on seismograms obtained at distances of 6.78 and 13.2 km from a blast of 1,221,000 lb of explosives and 22.0 km from a blast of 2,138,000 lb of explosives, at Promontory, Utah. The ratios of the total apparent seismic energy at these distances to the total energy of the explosives were plotted against distance, and the ratios of 0.027 and 0.017 were obtained by extrapolating this plot to zero and 2 km distance from the blasts, respectively. Using the relationship between total apparent seismic energy and magnitude given by Gutenberg and Richter (1956), magnitudes ranging from 4.0 and 3.9 (charge size of 490,500 lb) to 4.6 and 4.4 (charge size of 2,138,000 lb) were computed from the data applicable at zero and 2 km from the large quarry blasts detonated at Promontory and Lakeside, Utah, between 1956 and 1959.
For charge sizes ranging from 490,500 lb to 2,138,000 lb, an approximate linear relationship was found to exist between charge size and average record amplitude of the first cycle of the first arrival as measured on vertical-component seismograms obtained at Eureka, Nevada. The average vertical-component displacement amplitude of the first cycle of the first arrival was calculated to diminish by the 1.7 power of the distance between 6.78 and 22.0 km from the above blasts. The average vertical-component velocity amplitude of the first two cycles of the first arrival was calculated to diminish by the 1.8 power of the distance between 90.0 and 279 km from the above blasts.
Radiation of seismic surface-waves from finite moving sources
Authors: Ben-Menahem Ari 
Published: July 2021

AbstractA therory is proposed for the propagation of seismic surface-waves from finite moving sources. The method consists of obtaining, in the first place, basic solutions for surface displacements from directional sources. These solutions are integrated to obtain the effect of a moving fault with arbitrary dip angle. Displacements are evaluated for Rayleigh and Love waves at long ranges. It is shown that the dimensions of the source and the speed of rupture play an important role in the wave-pattern and cannot be ignored whenever the dimensions of the source are of the order of the radiation's dominant wave-length. It is demonstrated how this theory may lead to a derivation of the velocity of rupture and the length of faulting from seismic records of a single station.
On the nature of oceanic seismic surface waves with predominant periods of 6 to 8 seconds
Authors: Oliver Jack , Dorman James 
Published: July 2021

Abstract
The train of normally-dispersed, short-period, oceanic surface waves, commonly identified by the near-sinusoidal nature of all three components of ground motion in the period range of about 6 to 8 seconds, is shown to correspond to propagation in the first Love and first shear normal modes. Theoretical dispersion curves which agree with the observed dispersion of these short-period waves, as well as with dispersion of Rayleigh waves and Love waves of longer periods, are obtained for layered models of the oceanic crust which are consistent with results of seismic refraction studies. In order to obtain good quantitative agreement between theory and observation, it is essential that the effect of the small but finite rigidity of the deep-sea sedimentary layer be included in the calculations.
Willard D. Johnson and the strike-slip component of fault movement in the Owens Valley, California, earthquake of 1872
Authors: Bateman Paul C. 
Published: July 2021

Abstract
Maps and photographs made by Willard D. Johnson in 1907 and published by W. H. Hobbs in 1910, together with unpublished illustrations and an incomplete manuscript by Johnson, show convincingly that the faulting that took place near the town of Lone Pine at the time of the Owens Valley earthquake of 1872 involved both dip-slip and right-lateral components of movement. The pattern of movement at Lone Pine in 1872 is opposed to the postulate of regionally systematic left-lateral movement along the east side of the Sierra Nevada during the Cenozoic, but does not prove systematic regional right-lateral movement. Detailed geologic mapping is needed to fully describe the regional pattern of movement during the Cenozoic.
The transfer function of a short-period vertical seismograph
Authors: Bogert B. P. 
Published: July 2021

Abstract
We locate the poles and zeros of the transfer function of a seismograph which consists of the Geotech Model 1051 Benioff vertical seismometer and the Geotech Model 4500 galvanometer-phototube amplifier with a 5 cps galvanometer. A weighted least squares fit to the measured frequency response of the seismometer, assuming a damping ratio of 17 to 1, gives for the pole locations of the seismometer transfer function:
- 10 . 539 ; - 5 . 787 + i 7 . 407 ; - 5 . 787 - i 7 . 407
There is a triple zero at the origin. The overall seismograph transfer function has additional poles at
- 22 . 21 + i 22 . 21 ; - 22 . 21 - i 22 . 21 ; - 0 . 06283 ; - 29 . 62 + i 29 . 62 ; - 29 . 62 - i 29 . 62 ;
an additional zero at the origin, and a quadruple zero at infinity.
an additional zero at the origin, and a quadruple zero at infinity.
Seismic data collection, reduction, and digitization
Authors: Bogert B. P. 
Published: July 2021

AbstractThe facilities set up at the Bell Telephone Laboratories for seismic data collection and reduction are described. The digitization of the data so collected was carried out with existing equipment used for processing speech and visual data. We consider the seismic instrumentation and telemetry set up at the Chester Field Laboratory, Chester, New Jersey, the observation and recording equipment installed at the Murray Hill Laboratory, and finally and digitization and associated computer reduction to punched card form.