Free and forced shallow-water oscillations in a rotating channel of parabolic cross-section

Free and forced oscillations of shallow water in an infinitely long rotating channel of parabolic cross-section are analyzed. The pure cross-channel oscillations ofChrystal (1905) and solutions for zero rotation first discussed byProudman (1925) andHidaka (1932) are special asymptotic solutions for the free modes of this model. However, for increasingly large, along-shore wave number, our solutions donot uniformly approach those ofReid (1958) andBall (1967) for a single shore-line and semi-infinite ocean. A method of computing eigen frequencies and eigen functions for the general problem is described, and a sufficient number of these are exhibited graphically to permit visualization of the transitions between the asymptotic regions.The forced problem consists of an incoming wave-train or surge generated at the center of the channel. Amplitude and transports near the shore are computed for a wide range of dimensionless incoming-wave frequencies and rotational frequencies.     

Magneto-viscoelastic disturbances in a ‘hereditary layer’

Summary The dynamical response due to the interaction of viscoelastic field and magnetic field in a layer ofVito Volterra's hereditary model is analysed by making use of Laplace-transform.     

The electrostatic force between a charged conducting sphere and a charged dielectric sphere in an arbitrarily oriented external electric field

Summary The electrostatic force between a charged conducting sphere and a charged dielectric sphere in a uniform, arbitrarily oriented external electric field is obtained and presented in terms of force coefficients which depend only on the relative geometry of the two spheres and the dielectric constants of the dielectric sphere and the medium. When the dielectric constant of the dielectric sphere is allowed to approach infinity, the resulting computed force agrees with that ofDavis (1964) for two conducting spheres, and when the external field and the charge on the dielectric sphere are set to zero, the resulting force agrees with that ofHall andBeard (1975) for a charged conducting sphere near an uncharged dielectric sphere.     

Sull'analisi periodale dei diagrammi

Riassunto Dopo aver indicato un nuovo artificio per rendere più rapida la formazione di combinazioni selettive nella analisi periodale, si illustra un modello di analizzatore armonico che traduce con mezzi fotoelettrici gli schemi diLabrouste e diVercelli. Infine, si propone una variante costruttiva dell'analizzatore elettrico progettato dalLovera.

---

Summary After having showed a new way by which the process for making the selective combinations used for periodical analysis is hastened, an harmonic analysing device which traducts with photoelectric means the schemes ofLabrouste andVercelli is illustrated. Further, a change in the construction ofLovera's electric analyser is proposed.

     

Relazioni tra la velocità del vento e le caratteristiche del moto ondoso al largo e in costa

Summary The A. points out that the confirmation of the theory ofNeumann's significative waves, which differ from those ofSverdrup andMunk, would require observations of an accuracy not yet available. The existence of these waves would not change, anyhow,Sverdrup andMunk's conclusions out of the wind area.     

Über die Bindung der Aerosolteilchen auf der Oberfläche der Wolkenelemente

Summary The importance ofStefan's flow by collection of insoluble aerosol particles on the surface of the evaporating droplets by condensation has recently been emphasized mainly in connection with the possible wash-out mechanism in the atmosphere. A simple theory is deduced for the collection efficiency of insoluble particles on droplets under theStefan's force and a comparision is made with the binding of aerosol particles byBrown's motion and microturbulence of air flow. In general we must take in account the influence ofStefan's flow by calculating the wash-out efficiency.     

Die ≪Strahlung≫ bei Pouillet und Kirchhoff

Zusammenfassung Der Widerspruch zwischen den Strahlungsgesetzen der Physik und der Definition der Strahlung durchPouillet, die allen bisherigen Strahlungs-Messungen zu Grunde liegt, wird am Modell des schwarzstrahlenden Hohlraums vonKirchhoff gezeigt. Auch die Bestimmungen der Solarkonstante (Kalitins's Liste) sind verloren.

---

Summary The contradiction ofPouillet's radiation and the physical laws of radiation sinceKirchhoff, Boltzmann-Stefan, Wien, Lummer andKurlbaum is by the model of the black radiating body ofKirchhoff demonstrated. The measurements of radiation have followed til now to the antiquated idea ofPouillet. The determination of the solar constant as inKalitin's list represented also is lost.

     

Rayleigh wave propagation in a two-layer anisotropic media

Summary The possibility of propagation of Rayleigh waves in an incompressible crust of constant density and rigidity varying exponentially with depth lying on a semi-infinite transversely isotropic base has been discussed in this paper. Frequency equation has been derived and numerical calculations are made. The result obtained in this case is compared with that ofNewlands [3]²) andDutta [4].     

Global variation ofb in the gutenberg richter's relation LogN=a−bM with depth

Summary Variation ofb with depth has been studied using most likelihood method of estimatingb proposed byUtsu and it has been found thatb remains practicall constant upto a depth of 400 km, at which there is a sharp increase in the value ofb which decreases with depth. The distribution of Maximum magnitude with depth shows that the maximum magnitude decreases upto 300 km and below this level there is an increase in the maximum magnitude which again decreases with depth. The frequency of distribution ofb values is found to cluster around 0.8.     

Thermal regime of the Earth's outer core

Summary First an introduction into the dynamo problem and the core paradox is given. A novel theory of the volume dependence of Grüneisen's parameter is used for calculating the adiabatic temperatures on the assumption that the melting temperature of the material is reached at the boundary between the inner and outer cores of the Earth (IOB). On this condition, thermal convectionthroughout the outer core is impossible according to the melting-point curves ofKennedy andHiggins (1973) andLiu (1975), whereas it is permitted by that ofLeppaluoto (1972),Boschi (1975), andStacey (1977). Various possibilities of solving the core paradox are described.Mitt. d. ZIPE Nr. 682.     

L in Potsdam,Seddin and Niemegk

Summary This paper deals with the deriving ofL based on the observations in Potsdam, Seddin and Niemegk. The calculation uses the investigations on finestructure ofSq published in previous papers. Two sunspot cycles were used, a quiet one and a disturbed one. The influence of the solar activity is clearly marked. The results are in good conformity with those ofS. Chapman andAd. Schmidt, but there are remarkable deviations in the results caused by using hourly values and not hourly mean values. These results are discussed, especially their mean deviations.Communication No. 173 of the Central Earth Physics Institute of the German Academy of Sciences at Berlin, GDR-15 Potsdam, Telegrafenberg.-This paper was presented at the XV General Assembly of IUGG, held in Moscow in August 1971.     

Light scattering constants for a water cloud

Summary The study of radiative transfer in clouds and fog requires a knowledge of basic radiation constants. For this purpose the volume extinction, scattering, and absorption coefficients, the maximum absorption coefficients for composite spectral lines, and the coefficients used to expand the phase function into a series of Legendre polynomials for analytic representation of the phase function are provided in tabular and graphical format. The analysis for cloud droplets is based upon the rigorous electromagnetic theory. All Mie computations are carried out in an exact manner avoiding any approximations. Absorption line constants as computed here are based upon the investigations ofElsasser withCulbertson [5]³) andWyatt, Stull, andPlass [18]. Tabulations are made on the basis of fifty spectral intervals covering the entire solar and infrared spectra. Polarization effects are disregarded in this study.     

Focal mechanism study of South American earthquakes

Summary This study presents the focal mechanism solutions of four South American earth-quakes. These solutions have been determined using the sign of the initial motion ofP wave, and the polarization angle ofS wave. A regional study of the strike of the fault plane, the direction of motion, and the regional stress pattern has been made in which the focal mechanism solutions determined byStauder andBollinger were also used.     

CodaQ as a combination of scattering and intrinsic attenuation: Numerical simulations with the boundary integral method

Numerical modelling ofSH wave seismograms in media whose material properties are prescribed by a random distribution of many perfectly elastic cavities and by intrinsic absorption of seismic energy (anelasticity) demonstrates that the main characteristics of the coda waves, namely amplitude decay and duration, are well described by singly scattered waves in anelastic media rather than by multiply scattered waves in either elastic or anelastic media. We use the Boundary Integral scheme developed byBenites et al. (1992) to compute the complete wave field and measure the values of the direct waveQ and coda wavesQ in a wide range of frequencies, determining the spatial decay of the direct wave log-amplitude relation and the temporal decay of the coda envelope, respectively. The effects of both intrinsic absorption and pure scattering on the overall attenuation can be quantified separately by computing theQ values for corresponding models with (anelastic) and without (elastic) absorption. For the models considered in this study, the values of codaQ ^–1 in anelastic media are in good agreement with the sum of the corresponding scatteringQ ^–1 and intrinsicQ ^–1 values, as established by the single-scattering model ofAki andChouet (1975). Also, for the same random model with intrinsic absorption it appears that the singly scattered waves propagate without significant loss of energy as compared with the multiply scattered waves, which are strongly affected by absorption, suggesting its dominant role in the attenuation of coda waves.     

Questioni di ottica geometrica risolte con metodi meccanici

Riassunto Dall'analogia fra il principio ottico diFermat e quello meccanico della minima azione, l'A. ricava un metodo per determinare con mezzi meccanici: 1° la traiettoria di un raggio luminoso passante per due punti dati e separati da un lente; 2°) le superficie di lenti stigmatiche soddisfacenti a condizioni prefissate, in particolare a quelle diAbbe, Herschel.... Si accenna infine a possibili applicazioni nel campo delle lenti sferiche.

---

Summary From the analogy between the optical principle ofFermat and the mechanical one of minimum action, the Author deduces a method for obtaining with mechanical devices: 1) the optical path of a light beam passing through two given points and separated by a lens; 2) the surfaces of stigmatic lenses fulfilling prefixed conditions, particularly those ofAbbe, Herschell.... Further, it is hinted at possible applications in the field of spherical lenses.

     

Migration of historical earthquakes in California

Most large earthquakes of magnitude 6.0 in California during 1852–1987 appear to show a southeast-to-northwest tendency of epicenter migration. This finding is consistent with earlier findings ofSavage (1971) for a relatively few large earthquakes along the west coast of North America, and ofWood andAllen (1973) for smaller events along the San Andreas fault in central California. The average speed of migration is approximately 130 km/yr, which is within the range of speeds observed for other major seismic zones in the world. The epicenter migration in California may be the result of some small but broad-scaled episodic strain changes associated with creep waves induced by magma injections at the East Pacific Rise and propagating northwestwardly along a broad transform boundary between the Pacific and North American plates at subseismogenic depths as proposed bySavage (1971).     

A study of VLF field strength data: Both old and new

Summary Employing some old data ofRound et al. and the recent data ofHeritage et al., attenuation rates at VLF are deduced. For middle latitudes, day-time rates of less than 2 db per 1000 km of path length are not uncommon. These are in general accord with values derived from spheric waveforms and they are compatible with mode theory. An extensive bibliography is appended.     

Absolute calibration of a photoelectric condensation nucleus counter at low values of nucleus concentration

Summary A new absolute condensation nucleus counter was constructed to investigate the accuracy of the calibration widely used with the Pollak-Nolan photoelectric condensation nucleus counter. An attempt was made to standardize the conditions affecting calibration and, using the new counter, to recalibrate the photoelectric counter at values of extinction less than 16%.Over this extinction range, the present work indicates nucleus concentrations which are higher by about 30% than those given by the calibration ofPollak andMetnieks [8]³). In view of the great natural variability of Aitken nucleus concentrations, this discrepancy, if real, is of little meteorological importance.     

Il primo problema fondamentale della Geodesia ampliato nel campo di Somigliana

Sommario Dopo aver richiamato l'ampliamento ad un campo potenziale spaziale delle formule diLegendre che risolvono il primo problema fondamentale della Geodesia, l'A. applica tali formule al caso del campo diSomigliana, che ammette l'ellissoide come una delle superfici equipotenziali della famiglia; tale applicazione rappresenta la più naturale estensione ad un campo tridimensionale delle classiche formule ellissoidiche superficiali, e si accorda con l'adozione internazionale del campo diSomigliana per tutte le speculazioni della Geodesia dinamica.

---

Summary After having recalled the extension to a spatial potential field ofLegender's formulae solving the first fundamental problem in Geodesy, the author applies such formulae toSomigliana's field, which admits the ellipsoid as one of the equipotential surfaces of the family. Such application represents the most natural extension to a three-dimensional field of the classical ellipsoidal surface formulae, and agrees with the international adoption ofSomigliana's field in dynamic Geodesy.

     

Note on the propagation of waves from a spherical cavity in an infinite solid

Summary The present note, as its title implies, is concerned with the investigation of disturbances in an infinite elastic medium containing an initial magnetic field in the axial direction. The equations ofMaxwell, those of elasticity have been effectively made use of to solve the problem.