Showing papers in "Pure and Applied Geophysics in 1964"
TL;DR: In this article, the authors calculate local variations in the geomagnetic field, which are produced by stress changes in crustal rocks, from the stress patterns and the piezomagnetic properties of the rocks down to the Curie point isotherm.
Abstract: Local variations in the geomagnetic field, which are produced by stress changes in crustal rocks, are calculable from the stress patterns and the piezomagnetic properties of the rocks down to the Curie point isotherm. Release of stress during movement along a section of a transcurrent fault at an angle ϕ, measured clockwise with respect to the direction of magnetization of the rocks, produces a change in field similar to that which would be produced by the addition of a buried dipole of orientation (2ϕ±π/2), the alternative signs applying to right- and left-lateral faults. Computed seismomagnetic anomalies of horizontal, vertical and total field are plotted for different fault orientations in simple geological environments. Time-dependent magnetic anomalies with magnitudes of the order 10 gammas may commonly accompany the build-up of stress before an earthquake and provide a pre-indication of it.
139 citations
TL;DR: In this article, the authors developed the concepts of the front velocity, the front gradient, the travel time in space and on seismometric profiles, the profile velocity and the profile gradient in connection with the propagation of the fronts of elastic waves in solid isotropic and anisotropic media.
Abstract: Section 1 (and 11) develops the concepts of the front velocity, the front gradient, the travel time in space and on seismometric profiles, the profile velocity and the profile gradient in connection with the propagation of the fronts of elastic waves in solid isotropic and anisotropic media. The sectional velocity and the sectional gradient are defined in terms of the motion of the curve of intersection of a front with a fixed surface. Section 2 (and 12) relates the coefficients of elasticity of the medium, the front types, and their respective rays. In section 12, the theory of fronts of arbitrary shape and of the corresponding rays for any anisotropic, homogeneous or inhomogeneous solid medium is summarized. In section 3 (and 13), the law of reflection and refraction of fronts on surfaces of discontinuity of arbitrary shape is presented. Sections 4 to 6 (and 14 to 16) treat some elementary applications of seismic travel time methods to homogeneous, uniaxially anisotropic media (=transverse isotropy) in greater detail. In section 4 (and 14), the travel time of a direct front generated by a point source is considered and it is shown how the coefficients of elasticity of the medium can be found based on travel time measurements. The seismic prospection of a plane reflector and of a reflecting boundary of arbitrary shape and position are discussed in section 5 (and 15). In section 6 (and 16), the seismic refraction method is used to locate a plane boundary between a homogeneous, uniaxially anisotropic and a homogeneous isotropic medium, where the boundary is perpendicular or at an arbitrary angle to the direction of anisotropy.
79 citations
TL;DR: In this article, a statistical model of the geomagnetic field is derived, based on the assumption of an axial geocentric dipole field of strengthHe at the equator perturbed by randomly directed components of constant magnitudeh.
Abstract: A statistical model of the geomagnetic field is derived, based on the assumption of an axial geocentric dipole field of strengthHe at the equator perturbed by randomly directed components of constant magnitudeh. The model fits the dispersions found from an analysis of the 1945 field, and the ratioh/He obtained for this field and from the palaeomagnetic data both average to about 0.4. The model predicts that during reversal of the dipole field, the field intensity falls to between 0.2 and 0.4 of the steady field intensity, and this agrees with estimates made from the palaeomagnetic observations.
76 citations
TL;DR: In this article, the authors extend the results of the rotating cylinder experiments to the atmosphere of the sun and show that the layer in which spots are imbedded should exhibit a non-axially symmetric pattern, of the Rossby type.
Abstract: One of the main results of the rotating cylinder experiments ofFultz andHide is that the general flow regime in them is essentially determined by the ratio of the angular velocity of the fluid motions (relative to the cylinder) to that of the cylinder itself. Extending these results to the atmosphere of the sun, leads to the hypothesis that the layer in which spots are imbedded should exhibit a non-axially symmetric pattern, of theRossby type.
35 citations
TL;DR: In this article, aufstiege war erstmals moglich, den Gehalt der Atmosphare an Schwefeldioxyd und Stickstoffdioxyd bis in Hohen von 6000 m zu erfassen.
Abstract: Die vorliegende Arbeit behandelt die Ergebnisse von Messflugen zur Bestimmung der Konzentrationsverteilung von Spurengasen in der freien Atmosphare. Auf Grund dieser Aufstiege war es erstmals moglich, den Gehalt der Atmosphare an Schwefeldioxyd und Stickstoffdioxyd bis in Hohen von 6000 m zu erfassen. Die gewonnene mittelere Konzentrations-verteilung bietet die Basis zu Abschatzungen uber den Haushalt und die mittlere Verweilzeit von SO2 und NO2 in der Troposphare.
35 citations
TL;DR: In this paper, the covariance between ozone amounts and meridional wind in the lower stratosphere is calculated for all stations in the northern hemisphere for the IGY-IGC.
Abstract: Calculations of the covariance between ozone amounts and meridional wind in the lower stratosphere are presented for all stations in the northern hemisphere for the IGY-IGC. Northward ozone transport occurs by large-scale quasi-horizontal transient and standing eddies and the transport is a maximum early in the year. It is suggested that the transport is governed by the exchange of energy between the troposphere and stratosphere and data are presented on the energy transformations within the lower stratosphere and the transfer of energy into the region which support this suggestion. The vertical flux of energy is also calculated from tropospheric data and its seasonal changes are seen to be in the correct phase to explain the spring maximum in ozone amount.
32 citations
TL;DR: In this paper, the reliability of earthquake fault plane solutions using P and PKP first motion data is discussed, and effects of the usefulness of individual data, of the number and distribution of data around the focus, of great velocity contrasts in the focal region, and of the kind of projection technique are considered.
Abstract: The reliability of earthquake fault plane solutions usingP andPKP first motion data is discussed. Effects of the usefulness of the individual data, of the number and distribution of data around the focus, of great velocity contrasts in the focal region, and of the kind of projection technique are considered. The increase of the number of inconsistent data by a change in position of the three principal axes can be used as a more or less objective measure for the reliability of a solution. A selection of 52 mantle shock solutions is presented. More than 75% of these shocks is of the thrust (or block) and the normal or reverse fault motion type. Transcurrent type shocks decrease from 40 to 50% in the upper 200 km of the mantle to less than 15% below this level. Thrust (or block) type fault motions clearly represent the normal reaction of the deeper mantle material to earthquake generating stresses.
29 citations
TL;DR: In this paper, anisotropy of magnetic susceptibility was measured in hexagonal columns of basalt and the observed magnetic grain alignment indicated that the flow was essentially uniform and horizontal across the hexagons which were sampled.
Abstract: Evidence for flow structure within hexagonal columns of basalt has been sought, using measurements of the anisotropy of magnetic susceptibility. The observed magnetic grain alignment indicates that the flow was essentially uniform and horizontal across the hexagons which were sampled. The flow probably occurred during emplacement of the lava; there is no evidence of convection within the hexagons, either from the degree of grain alignment or its orientation.
25 citations
TL;DR: In this article, two approaches are used to describe and distinguish between those regions of the atmosphere which most closely resemble heat engines and those which operate like refrigerators, based on the conversion from eddy potential energy to mean zonal potential energy.
Abstract: Two approaches are used to describe and distinguish between those regions of the atmosphere which most closely resemble heat engines and those which operate like refrigerators. Estimates of the conversion from eddy potential energy to mean zonal potential energy are presented as a function of height, latitude and season; the region of forced motion (or refrigerator) in the lower stratosphere appears to be closely related to the maximum westerly winds of the upper troposphere. A preliminary attempt is made to relate some values of mass transport derived from the observations of trace substances to the energy conversions.
23 citations
TL;DR: In this article, the mean zonal and meridional wind components of the northern hemisphere at different pressure levels for the summer season June-August have been determined and the mean meridion mass circulation has been computed as a function of latitude.
Abstract: The mean zonal and meridional wind components of the northern hemisphere at different pressure levels for the summer season June–August have been determined and the mean meridional mass circulation has been computed as a function of latitude. From the mass circulation the meridional flux of moisture is computed for the latitudinal belt 0°–45° N. Using the horizontal divergence of this flux the average difference between precipitation and evapotranspiration from the earth's surface is evaluated.
21 citations
TL;DR: In this paper, a short description of the field distance installation for measuring spectral albedo as relation of semi-spherical fluxes of reflected and incoming radiation is made, and data on the measurements of spectral Albedo in the wavelength range from 450 to 950 mμ for different natural surfaces are given.
Abstract: The short description of the field distance installation for measuring spectral albedo as relation of semi-spherical fluxes of reflected and incoming radiation is made. Data on the measurements of spectral albedo in the wavelength range from 450 to 950 mμ for different natural surfaces are given.
TL;DR: In this article, it was suggested that the eddy processes in the tropical regions of the middle troposphere operate in an inverse manner as compared with a normal heat engine, in common with the situation in the lower stratosphere, the region is characterized by a countergradient horizontal eddy heat transport and a rising of colder air and sinking of warmer air on the scale of the large eddy process.
Abstract: It is suggested on the basis of the study of observational data gathered byJ. P. Peixoto that the eddy processes in the tropical regions of the middle troposphere operate in an inverse manner as compared with a normal heat engine. Thus, in common with the situation in the lower stratosphere, the region is characterized by a countergradient horizontal eddy heat transport and a rising of colder air and sinking of warmer air on the scale of the large eddy processes.
TL;DR: In this article, a pilot investigation was made of the downward flux of downwind momentum through the upper layers of the water, by measuring the covariance between the horizontal and vertical water velocity components.
Abstract: A pilot investigation was made of the downward flux of downwind momentum through the upper layers of the water, by measuring the covariance between the horizontal and vertical water velocity components. Power spectrum analysis showed the effect to be due largely to the surface waves present.
TL;DR: In this article, the authors present a survey of the state-of-the-art technologies used in the field of data collection and analysis of data collected by the National Institute of Standards and Technology.
Abstract: Разработан обЩий метод определения кривой распределения частиц дисперсной системы по размерам, исходя из данных о её спектральной прозрачности, основанный на преобразовании Меллина. Метод не содержит никаких произвольных предложений о характере спектра частиц и даёт ответ в общем виде. Предложена простая расчётная схема, приведены примеры обращения, оценена область спектра и точность измерений прозрачности, необходимые для получения обращения с заданной точностью. Существенно, что расчётная схема устойчива по отношению к ошибкам измерения и расчетов, и содержит умеренные требования к их точности.
TL;DR: In this article, the results of thermal and alternating magnetic field stability tests indicate that the resultant direction is that of the earth's magnetic field at the time of cooling, which confirms the probable Permian age of the intrusion and the wide divergence of Australian from European and North American pole positions of this age.
Abstract: Directions of natural remanent magnetization aftermagnetic cleaning of specimens from monzonite porphyry at Milton are given. Thermal and alternating magnetic field stability tests indicate that the resultant direction is that of the earth's magnetic field at the time of cooling. Comprison of the pole position calculated from this result with other pole positions from rocks of known age confirms the probable Permian age of the intrusion and the wide divergence of Australian from European and North American pole positions of this age.
TL;DR: In this paper, the authors investigated local differences of geomagnetic variations by three ambulant gomagnetic variographs afterFanselau, showing the influence of the variometer needles on each other, the dependence of the scale-values on the position of the lightpoint and the changing of scale-value with temperature and with the value of the vertical intensity.
Abstract: ZusammenfassungDie lokalen Unterschiede der geomagnetischen zeitlichen Variationen [1, 2] wurden mit Hilfe von 3 Reiseregistrierstationen nachFanselau [3] untersucht. Hier werden die gegenseitige Beeinflussung der Variometernadeln, Veränderung der Skalenwerte über die Breite des Registrierpapiers und die Abhängigkeit der Grösse des Skalenwertes von der Temperatur sowie von der Grösse der Vertikalintensität untersucht. Die reduzierten Skalenwerte besitzen im Mittel eine Unsicherheit von nicht mehr als 0,6%. Eine grössere Genauigkeit kann bei Feldmessungen nicht erwartet werden. Aufstellung und Justierung der Stationen im Felde werden beschrieben.SummaryLocal differences of geomagnetic variations [1, 2] were investigated by three ambulant geomagnetic variographs afterFanselau [3]. The influence of the variometer needles on each other, the dependence of the scale-values on the position of the lightpoint and the changing of the scale-value with temperature and with the value of the vertical intensity are shown. The reduced scale-values have an uncertainty of not more than 0.6%. A higher accuracy is not to be expected for field measurements. The menagement and the adjustment of the stations in field are described.
TL;DR: In this paper, the propagation of Love type waves on a spherical model' in the mantle of which the rigidity and density vary exponentially with the radial distance while in the core they remain constant.
Abstract: The propagation of Love type waves on a spherical model' in the mantle of which the rigidity and density vary exponentially with the radial distance while in the core they remain constant — has been investigated. The frequency equation that has been worked out has been examined in detail for the existence of root in the particular cases when they involve Bessel Functions of smallest and largest orders.
TL;DR: In this paper, the possible modes of vertical transport of angular momentum in the atmosphere are considered, and it is pointed out that the transport of momentum downward from the region of maximum westerlies would have to be accomplished by the mean meridional motions, through the action of Coriolis torques'.
Abstract: The possible modes of vertical transport of angular momentum in the atmosphere are considered. Momentum balance calculations for both hemispheres show the possibility of countergradient transport by vertical eddies in the region of the mid-latitude jet. As a consequence, it is pointed out that the transport of momentum downward from the region of maximum westerlies would have to be accomplished by the mean meridional motions, through the action of “Coriolis torques’. The same mechanism may account for a large part of the upward transport in the tropics. The very approximate nature of the calculations must, however, be borne clearly in mind.
TL;DR: In this article, die Ergebnisse einer Berechnung des geomagnetischen Potentials in Form einer Reihenentwicklung nach Kugelfunktionen bis zur 15. Ordnung auf Grund der magnetischen Weltkarten fur die Epoche 1945,0 von E. H. Vestine und andern vorgelegt.
Abstract: Es werden die Ergebnisse einer Berechnung des geomagnetischen Potentials in Form einer Reihenentwicklung nach Kugelfunktionen bis zur 15. Ordnung auf Grund der magnetischen Weltkarten fur die Epoche 1945,0 vonE. H. Vestine und andern vorgelegt. Bei der Ableitung des Potentialausdrucks nach der Methode der kleinsten Quadrate wurden die Orthogonalitatseigenschaften der Kugelflachenfunktionen vollstandig ausgenutzt.
TL;DR: In this paper, Maxwell's electromagnetic equations together with the equation of motion of two types of viscoelastic solids have been used to deal with the propagation of magneto-thermoviscoelastic plane waves.
Abstract: In the present paper,Maxwell's electromagnetic equations together with the equation of motion of two types of viscoelastic solids have been used to deal with the propagation of magneto-thermoviscoelastic plane waves.
TL;DR: In this article, it was shown that needle-shaped ice crystals are grown in an atmosphere containing traces of nitrous gases, and the amount of electrical charge generated when sharp crystal points break away, is between 10 and 50 times as high as in the case of crystals grown in absence of Nitrous gases.
Abstract: If needle-shaped ice crystals are grown in an atmosphere containing traces of nitrous gases, the amount of electrical charge generated when sharp crystal points break away, is between 10 and 50 times as high as in the case of crystals grown in absence of nitrous gases A definite relation has been found to exist between the NO3′ ion concentration of the ice crytals and the amount of charge (average value 2.7×10−8, maximum value 13×10−8 coulombs per gram of ice splinters) generated upon fragmentation. The relation found is possibly of importance with respect to thunderstorm electricity generation.
TL;DR: In this paper, an attempt has been made to investigate the wave-motions in a poro-viscoelastic medium traversed by a static magnetic field, by using the equations ofMaxwell, and those ofBiot.
Abstract: In the present note, an attempt has been made to investigate the wave-motions in a poro-viscoelastic medium traversed by a static magnetic field, by using the equations ofMaxwell, and those ofBiot.
TL;DR: In this paper, a formal approach to a closed steady-state theory of the mean axially-symmetric variables is presented, which involves alternating iterative solutions of the energy and momentum equations.
Abstract: A possible formal approach to a closed steady-state theory of the mean axially-symmetric variables is outlined. The approach involves alternating iterative solutions of the energy and momentum equations. In these equations the effects of transient eddy phenomena of all frequencies are assumed to be parameterized in terms of the mean symmetric variables.
TL;DR: In this paper, the influence of local contamination from a car park and a large domestic heating furnace on nuclei counts was studied and it was found that even downwind at a distance of about 1000 feet (or 350 m) the contamination by these sources is negligible.
Abstract: Concentrations of condensation nuclei were measured on the slopes of the Little Whiteface Mt. between 1200 and 3670 feet altitude in July 1963. On the average the concentration decreases exponentially with altitude and shows a strong dependence on wind direction. In addition, the influence of local contamination from a car park and a large domestic heating furnace on nuclei counts was studied and it was found that even downwind at a distance of about 1000 feet (or 350 m) the contamination by these sources is negligible.
TL;DR: In this paper, the authors studied whether annual precipitation over the Colorado watershed is determined by occurrence or non-occurrence of a few large storms; or by other controls such as variations in frequency of minor disturbances.
Abstract: We wish to learn whether annual precipitation over the Colorado watershed is determined by occurrence or non-occurrence of a few large storms; or by other controls such as variations in frequency of minor disturbances. It is found that there is a semi-constant ‘noise’ level of about six inches precipitation per year, composed of small rains. Occasional very large storms do contribute to rank order of annual precipitation over the available data sample which covers the period 1930–1960. However, most contribution to the rank order is derived from medium-sized storms yielding 0.3–1.2 inches of precipitation over the basin. Since storm yield depends mainly on duration rather than on precipitation intensity per day, a good correlation exists between annual precipitation and the number of days with precipitation above a certain threshold.
TL;DR: In this paper, the authors derived closed formulas for the space gravity field in which one of the equipotential surfaces is a triaxial ellipsoid using the Pizzetti-Somigliana method and using elliptic integrals.
Abstract: Adopting thePizzetti-Somigliana method and using elliptic integrals we have obtained closed formulas for the space gravity field in which one of the equipotential surfaces is a triaxial ellipsoid. The same formulas are also obtained in first approximation of the equatorial flattening avoiding the use of the elliptic integrals. Using data from satellites and Earth gravity data the gravitational and geometric bulge of the Earth's equator are computed. On the basis of these results and on the basis of recent gravity data taken around the equator between the longitudes 50° to 100° E, 155° to 180° E, and 145° to 180° W, we question the advantage of using a triaxial gravity formula and a triaxial ellipsoid in geodesy. Closed formulas for the space field in which a biaxial ellipsoid is an equipotential surface are also derived in polar coordinates and its parameters are specialized to give the international gravity formula values on the international ellipsoid. The possibility to compute the Earth's dimensions from the present Earth gravity data is the discussed and the value ofMG=(3.98603×1020 cm3 sec−2) (M mass of the Earth,G gravitational constant) is computed. The agreement of this value with others computed from the mean distance Earth-Moon is discussed. The Legendre polinomials series expansion of the gravitational potential is also added. In this series the coefficients of the polinomials are closed formulas in terms of the flattening andMG.
TL;DR: In this paper, the vertical profiles of the radiation balance and its components for summer and autumn seasons measured by standard actinometric instruments fixed on free balloons were considered and the values of radiational temperature changes in the layers of 1000 to 500 and 1000 to 20 mb.
Abstract: The present research considers the vertical profiles of the radiation balance and its components for summer and autumn seasons measured by standard actinometric instruments fixed on free balloons and gives the values of radiational temperature changes in the layers of 1000 to 500 and 1000 to 20 mb.
TL;DR: In this article, the effect of random motions in a star gas was investigated and the conservation integrals for momentum and kinetic energy were formulated and the kinetic energy was further partitioned into kinetic energy of the large scale flows and kinetic energies of the random star motions.
Abstract: This paper supplements and extends previous discussions of galaxies in the light of meteorological theory by including explicitly the effect of random motions in a star gas. The conservation integrals for momentum and kinetic energy are formulated and the kinetic energy is further partitioned into kinetic energy of the large scale flows and kinetic energy of the random star motions. The kinetic energy of the random star motions is analogous to the internal energy in an ordinary gas and is transformed into kinetic energy of the fluid flow according to a law which is a generalization of the first law of thermodynamics as applied to fluids. It is possible to make more detailed division of the kinds of energy and their laws of transformation.
TL;DR: In this article, a review of palaeomagnetic investigation carried out in Czechoslovak hydrothermal deposits is presented, which is consistent with the geophysical interpretation of the polar wandering curve for Europe.
Abstract: The present contribution contains a brief review of palaeomagnetic investigation carried out in Czechoslovak hydrothermal deposits. So far polar wandering has been considered on the basis of palaeomagnetism of lavas and red sediments; to first approximation it agrees with palaeoclimatic data. Since the products of hydrothermal mineralizations have displayed a high stability of the magnetic parameters used in palaeomagnetism, the treatment of a greater amount of statistical material yielded data for deriving the polar wandering path during geological history. By analyzing the curve obtained it is possible to derive some geochronological conclusions concerning the age of the ore-yielding processes in the principal Czechoslovak metallogenic areas. In this way a new dating technique for products of hydrothermal mineralizations is presented based on the study of palaeomagnetic properties. At the same time, these new results are consistent with the geophysical interpretation of the polar wandering curve for Europe.
TL;DR: In this paper, it was shown that the nonequilibrium formalism can be directly applied to statistical processes where there is a non-negative constant of the motion, and the total mass (of contaminant, tracer etc.) contained in a fluctuating system is taken as such a constant of motion.
Abstract: A previously noted analogy between certain transport equations and the heat conductivity equation is further analyzed. It is shown thatPrigogine's nonequilibrium formalism can be directly applied to statistical processes where there is a non-negative constant of the motion. If the total mass (of contaminant, tracer etc.) contained in a fluctuating system is taken as such a constant of the motion, a statistical theory of the corresponding transport process is obtained.