Propagation of Love type waves in a non-homogeneous layer lying over a vertically semi-infinite homogeneous isotropic medium

Summary The aim of this paper is to study the propagation of love-type waves in a homogeneous half-space overlain by a heterogeneous crust with various types of heterogenety. Frequency equations are obtained in each of the cases and numerical calculations are done in some cases and the results thus obtained are compared with those done byJeffreys andMitra [3]²).     

Resolution of tidal high water anomaly

Summary As a preliminary calculation of the Equilibrium Theory of Tides, a fictitious Earth-Moon configuration is analyzed byThomson andTait [1]²), in which non-sphericity of oceans is attributed to the attraction exerted by a stationary Moon. A rise of level is found at the which Earth-Moon orbital motion is accounted. This feature, which is utterly contradictory to fact according toG. H. Darwin [2] prompted him to remark that the equilibrium theory is nearly as much wrong as possible, in respect to the time of high water. An elementary analysis is given which, in demonstrating an exactly opposite finding, suggests a manner of removing one of the long-standing obscurities of the Laplace theory, remarked upon byHough andAiry, and in recent times byC. Eckart [3].     

Discussion on the atmospheric radiation tables byElsasser andCulbertson

Summary The radiation tables byElsasser andCulbertson [1]²) are based upon an integrated form of the radiative transfer equation. Unfortunately, a term dealing with the temperature dependency of the transmission function is left out. This leads to an inconsistency of their analysis. It is the aim of this paper to correct and to modifyElsasser's graphical-numerical procedure such as to make his treatment internally consistent.     

High magnitude global seismicity and lateral velocity gradients

Summary A new significant correlation has been sought between high magnitude global seismicity and lateral surface wave velocity gradients. Rayleigh wave velocity divisioning of Eurasia, Africa, Pacific Ocean, Atlantic Ocean and Indian Ocean into regions of similar group velocity dispersion character of 30 sec period bySanto andSato [1]³) has been mainly used for calculating the gradients. It is quite striking to note that all earthquakes of magnitude 8.6 and above during 1897–1956 have occurred in regions having gradients of the order of 1.5·10^–3 sec^–1.Finally, some potential areas for high magnitude earthquake occurrences are predicted and the possible velocity gradients in regions, where division pattern is not yet investigated like South America and Australia, are also estimated.N.G.R.I. Contribution No. 70-170.     

A layered micropolar half space

Summary Wave propagation in a semi-infinite micropolar isotropic elastic solid lying over another micropolar isotropic elastic solid is considered using the theory of micropolar elasticity initiated byEringen [3]²). The relation between the group velocity and the speed of propagation is obtained for the new type of surface wave.     

Some hydrodynamic problems for a nepheloid zone

Summary A layer of a few hundred meters thickness with suspended matter (a nepheloid zone) was discovered byEwing andThorndike [4]³⁾ near the bottom on the continental slope of the North Atlantic. A downward pressure gradient is produced in this layer due to increment of water density with suspensoid. When only the Coriolis force balances with this pressure gradient, a bottom nepheloid current flows southwestward parallel to the depth contours with a velocity of about 10 (cm/sec) for a slope of one degree. The pressure gradient for fluid with locally variable density above a sloping bottom is treated and an extra term due to density gradient along the slope is derived. The vertical profiles of the nepheloid current with an effect on the vertical eddy viscosity are computed. Two kinds of vertical distributions of eddy viscosity are determined from the observed nepheloid distributions and used in the calculations: constant but different values at two layers and those increasing with height. The effect of the change of density along the bottom is treated by introducing dimensionless variables. Rossby number of the nepheloid current becomes about 10^–2 indicating inertia terms to be negligible. Rossby number of turbidity currents ranges from 2 (in a decaying area) to 5 (developing area), suggesting that inertia terms are more important than Coriolis terms. The trajectories of turbidity currents are computed from motion of a mass of mud under the Coriolis force and friction, and the results are applied to those inferred byHand andEmery [6] in the San Diego Through off California.LGO Contribution Number 925.     

Least square criterion for isostasy

Summary Least square criterion has been introduced to specify the order of isostatic compensation of mountains. The hydrostatic stability of the mountains is of basic significance in plate tectonics. However different concepts of isostasy differ in the evaluation of its order. An elegant and rapid technique is developed which extends the symmetric matrix method of root estimation byNegi andGarde [1]³) to provide a stability test through the mathematical expectation of the root increment. Application is illustrated for Rocky Mountains, United States.     

A determination of the wind-driven ocean circulation from the vorticity budget of the atmosphere

Summary The annual mean distribution of the surface stress curl over the Northern Hemisphere has been estimated from the horizontal vorticity advection in the atmosphere by using the upper-wind statistics as published byCrutcher [2]³). The results are used to compute the wind-driven mass transport (Sverdrup transport) in North Atlantic and North Pacific. The calculated intensity of the Gulf Stream is largest at the latitude 35°N, where a mass transport of 45×10⁶ tons sec^–1 is obtained; for the maximum intensity of the Kuroshio current a value of 60×10⁶ tons sec^–1 is obtained.Research supported in part by the Section of Atmospheric Sciences, National Science Foundation, Grant GP-2561.The research for this study was started by the author at the Department of Meteorology and Oceanography, The University of Michigan, Ann Arbor, Mich.     

Correlation between terrestrial heat flow and thermal conductivity

Summary The significant correlation coefficient between the terrestial heat flow and thermal conductivity computed from the continental heat flow data byHorai andNur [1]²) may be explained as a natural consequence of terrestrial heat flow through a random medium. The theory predicts a value of 0.40 for the correlation coefficient. A simple statistical test shows that the majority of the computed coefficients belong to the statistical population whose mean is equal to the theoretical correlation coefficient. There are, however, a few observations of unsually high correlation coefficient which cannot be explained by the above hypothesis.     

The viscous damping of internal waves on the rotating earth

Summary A formula is derived for the spatial attenuation of the two possible modes of oscilation of a two-layer, rotating system. If the long-wave approximation is made, it is found with reference to the internal mode that this formula disagrees with an earlier result obtained byRattray [8]²).     

The thermal diffusivity of red sandy soil at Waltair

Summary The study of heat exchanges or temperature changes in the surface layers of the soil are important in agricultural science at tropical latitudes. The quantity, thermal diffusivity largely determines the temperature change produced in any layer of the soil when heat is conducted there from an adjacent layer. Therefore, the authors have determined the thermal diffusivity of the soil from range and lag methods suggested byJohnson andDavies [15]²) andCoutis [7] respectively. The values of diffusivity cbtained from these methods agree well with each other. The effect of soil moisture on diffusivity has been studied. The diffusivity increases with the increase of moisture in the surface layers of the scil. The ratio of ranges of soil temperature at different depths is found to be approximately constant which is in agreement with the theory of heat flow into the soils. The results of diffusivity obtained from these methods agree well with those results of past workers. The mean value of the thermal diffusivity of red sandy soil at the experimental site of Waltair is found to be 6.336×10^–3 cm²/sec.     

Isocystis pallida—Blaualge oder hefeartiger Pilz?

Zusammenfassung Die vonWoronichin [29] alsIsocystis pallida beschriebene Cyanophycee, welche vonAnagnostidis [1] h?ufig in griechischen Thermalquellen gefunden wurde, hatGeitler [17] zu den hefeartigen Pilzen der GattungTorulopsidosira gestellt. Diesen Organismus, den wir in verschiedenen Thermen reelm?ssig angetroffen haben, (Griechenland, Ungarn, Schweiz) untersuchten wir an Hand umfangreicher Materialproben. Statistische und zellphysiologische Versuche sowie systematische Vergleiche führten uns zu dem Ergebnis, diesen Organismus alsI. pallida (Woronich.) bei den Cyanophyten zu belassen, bis biochemische Resultate seine Zugeh?rigkeit zu den Blaualgen in Frage stellen sollten.

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Summary The blue-green alga described byWoronichin [29] asIsocystis pallida and often found byAnagnostidis [1] in Greek hot springs has been classified byGeitler [17] among yeast-like fungi of the genusTorulopsidosira. This organism was regularly found in various hot springs (Greece, Hungary, Switzerland). Statistical and cytological tests, as well as systematical comparisons, led us to conclude that it should be classified asI. pallida (Woronich.) among the Cyanophyta until biochemical results should give cause to doubt that it belongs to the blue-green algae.

     

Atmospheric ozone and the movement of the air in the stratosphere

Using over 2200 ozonesonde ascents, published byHering andBorden [1]–[5] and byDütsch et al. [6], [7], the average vertical distribution of the ozone mixing ratio is found for different latitudes and for different seasons up to a height of 30 km. The method by which the ozone formed at great heights in low latitudes becomes concentrated in the lower stratosphere of high latitudes is discussed, and the meridional circulation theory is strongly suggested.Oxford, May 1972.     

On coda waves of earthquakes

Summary Coda waves viz. the tail portion of an earthquake record have been observed and analysed byCarder, Macelwane and others. They showed that the periods of such waves increase with the increase of epicentral distances.Carder observed that these waves have very little transverse component so that these may be considered as of the type of Rayleigh waves. RecentlyOmote showed that the Coda waves contain three periodsT ₁,T ₂,T ₃ of whichT ₁ increases with epi-central distances as observed by previous observers. ButT ₂,T ₃ remain constant for all earthquakes from different epicentral distances.Omote tried to explain this phenomenon by considering that the surface of the earth consists of several layers andT ₂,T ₃ are free oscillation periods of the surface layers.T ₁ period has been explained bySezawa and also byJeffreys which has been shown byGutenberg. The author has attempted to explain the periodsT ₂,T ₃ by considering passage of cracks at the focal region. The Rayleigh wave character of Coda waves and low velocity of such waves have been explained.     

Estimation of in-situ hydraulic diffusivity of rock masses

A method of estimating in-situ hydraulic diffusivity of rock masses by means of well-injection history and frequency of induced seismicity is presented. The method is based on the diffusion of injected fluid from a spherical cavity in a poroelastic half-space and the effective stress theory, as proposed byTerzaghi (1925, 1936) andHubbert andRubey (1959). Application of the method to two different regions, one in western New York and the other in Japan, resulted in estimated diffusivities of the order 10³ and 10⁴ cm²/sec, respectively. These values lie within the range of published estimates of in-situ diffusivity by other means, a summary of which is presented in tabular form. The calculated diffusivities suggest that the characteristic time of fluid diffusion is close to 0.1, rather than unity, as is sometimes assumed in the literature.     

On the chemical composition of atmospheric aerosols — Part II: Trends between some chemical components of rainwater and physical variables over the United States

Summary Annual average results of rainwater analysis, carried out byC. Junge at about 60 stations of the United States sampling network are used in an attempt to correlate the ionic species present in rain, as a general contribution to atmospheric chemicstry. Correlation with physical parameters is attempted at the same time in some cases, and the resulting trends discussed. The results obtained are presented in the general form of linear and planar correlation, and linear regression coefficients.     

An investigation of the size frequency resolution of an aerosol by the static method of diffusion

Summary Theoretical considerations are put forward for identifying the Dynamic and Static Methods of Diffusion measurements of aerosol particles. On the basic of this equality the Exhaustion Method of Diffusion developed byPollak andMetnieks for the size-frequency resolution of a heterogeneous aerosol by Dynamic Diffusion Methods should be applicable to Static Methods. This hypothesis is tested using a Pollak-Nolan nucleus counter as decay vessel. It is shown that turbulence in the counter is the most serious obstacle against this type of approach to finding the size components of an aerosol. The time involved, the high humidity in the counter and a hypothetical nucleus-free zone are other major difficulties for relatively large Aitken nuclei. It is established, however, that for particles whose diffusion coefficient is of the order of 10^–3 cm² sec^–1, the proposed method should be quite workable.     

Moving load on a porous,liquid-saturated solid

Summary The object of this paper is to study the stresses produced in a porous liquid-saturated solid of the type considered byBiot [1]²) by a normal load moving along the surface of such a solid. Two cases have been considered. In the first case, the porous solid is taken to be semi-infinite, while in the second case we consider a layer of the liquid-saturated porous solid resting on a smooth rigid foundation. Expressions have been obtained for the stresses at any point in the medium due to a normal load moving along the free surface of the porous solid. Detailed numerical calculations have been carried out for liquid-saturated sandstone, using the data given byFatt [9] for such a medium. These calculations show that the normal stress zz in the solid falls off approximately as 1/z with increase in the depthz below the free surface, and that the stresses in the solid and in the liquid fall off rapidly as we move away from the point directly below the moving load.     

Some aspects of vortices in rotating stratified fluids

Summary Ideas concerning the overturning of unstably stratified, rotating fluids are explored using potential vorticity.A set of equations governing axi-symmetric flow in a quasi-Boussinesq system are found based on the gradient wind approximation, and a transformation analogous to that developed byHoskins [6] is used.The time-development of a linear, thermally unstable vortex under the action of Ekman pumping is studied with these equations. The changing radial scale during amplification of the vortex is well represented.Finally, some exact steady vortex states for stably stratified fluids are found and their possible relevance to atmospheric vortices is discussed.     

Die abschnittweise Darstellung einer gemessenen Laufzeitkurve mit abgebrochenen Potenzreihen und ihre Auswertung in der Refraktionsseismik

Zusammenfassung Es wird eine einfache und für numerische Rechnungen besonders geeignete Methode zur direkten Auswertung von seismischen Refraktionsmessungen entwickelt und an einem Beispiel [Eisdickenmessungen in Baffin Island,Röthlisberger (3)] erläutert.

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Summary A simple and for numerical calculation especially convenient method is developped for the direct inerpretation of travel-time curves in refraction seismic. Finally an example [Firn and ice thickness measurements in Baffin Island, byH. Röthlisberger (3)] is given.