Normal density earth models

Summary Models of the Earth's density, close to thePREM model, have been derived, they reproduce the external normal gravitational field of the Earth and its dynamic flattening, and are referred to as normal density models. The Earth's surface is approximated by an ellipsoid of the order of the flattening, or of its square. Of the group of normal models sgtisfying the solution of the inverse problem, the normal density modelHME2 is recommended. The spherically symmetric density modelPREM, which was corrected in the course of solving the inverse problem, thus creating the modifiedPREM-E2 model, was used as the a priori information.

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¶rt; ¶rt;u an¶rt;u nmmu uu ¶rt;uPREM (m. a. a ¶rt;u nmmu), aumau n m u¶rt;mu na¶rt;am auaumau n u. m u annuum am unu¶rt; au. uau amu a ¶rt; mam H==0.003 273 994. ma ¶rt; a ¶rt; ¶rt;m ¶rt;HME2. am anu u a ¶rt; nmmu a unaa ¶rt; a¶rt;ua umua ¶rt;PREM. ¶rt;aam ¶rt;uuau m ¶rt;u n¶rt; aauPREM-E2.

     

Transfer impedance of a probe in a drifting plasma

au un¶rt;a umu ¶rt;a na nu nauuu ¶rt;a uam mmu amm na aa. amau aa auum m mnam u mu ¶rt;a, m unam ¶rt; ¶rt;uamuu u na.     

Sensitivity of the Gs 12 gravity meter to vibrations

nuaa m¶rt;ua u mam unmauaumaGs 12 No. 129 a uauu ¶rt;uana amm 0.02–30. a uu a uau nam auu au u auma naamauma a mua ma u n¶rt;a mumm a ¶rt;uu ¶rt;ama ammau uu .     

The periodicity of aurorae in the years 1001–1900

Summary The sequence of aurorae, observed at latitudes up to 55° between the years 1001 and 1900 was processed by methods of spectral analysis. The same methods were applied to parts of various duration of this interval. The periods predominant in the time series under investigation were determined. In all the selected parts of the interval, these periods are always located within the same frequency band. Their position is related to the periods corresponding to mutual conjunctions of the large planets.

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¶rt; n uu, a¶rt;au a uma ¶rt; 55° nu¶rt; 1001–1900, ama nu nu m¶rt; nma aaua. a n¶rt; ¶rt; am a ¶rt;u m umaa. u n¶rt; na¶rt;au nu¶rt; u¶rt;a ¶rt;a. mu nu¶rt; ¶rt; a am umaa ¶rt;a a¶rt;m ¶rt;ua ¶rt;uaan amm. nu mum nu¶rt;au, mmmuu au u u nam.

     

Motion of particles in turbulent flow: Hyperbolicity,strange attractors and dynamic stochasticity of a system

¶rt;naa, m ma um uu maunuu m am muu ¶rt;uauu um. nua a mau ammama a, n¶rt; mnu ma u u au uu u¶rt;mu.     

Power radiated by a VLF loop antenna in the ionospheric plasma

Summary The radiation power a VLF loop antenna with an arbitrary orientation of the loop's plane relative to the direction of the external magnetic field is calculated and its portion, transferred to the electromagnetic part of the excited spectrum, is determined.

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am umaa m uu am c nu umau nmu uma n m¶rt; a¶rt;um¶rt; n u n¶rt;a ma am mu uu, u¶rt;a ma¶rt;um am am cnma ¶rt;a au.

     

Computation of rays in an inhomogeneous transverselly isotropic medium with a non-vertical axis of symmetry

a m¶rt;uu nua [1], ¶rt; ¶rt;uua au u a 2-D ¶rt;¶rt;, nn umn ¶rt; a muu. nua mam uu ¶rt; m nua n¶rt; ¶rt;.     

ЧИСЛЕННЫЕ ЭКСПЕРИМЕНТЫ С ИСКУССТВЕННЫМИ ЯДРАМИ СУБЛИМАЦИИ В СТРУЙНОЙ МОДЕЛИ КУЧЕВОГО ОБЛАКА

nuam aau ¶rt; amu a um ¶rt; ¶rt;a uauu. ¶rt; ¶rt;a, ¶rt;mu auumu m mnam u nu mum ¶rt;a, umam m ¶rt;u z aa n¶rt; uuu, a aau. u¶rt; auum ¶rt;au z naa m mauu ¶rt; amu, naam, m ¶rt;au ¶rt;z naa zauuam u amu ¶rt;.

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Summary A formation of ice particles on artificial deposition INis described. INacting in dependence on the temperature and supersaturation over the ice are considered in the 1 D SSconvection cloud model with detailed microphysics including freezing. The limiting influence of the water vapour pressure upon the concentration of active INis shown resulting from the dependence of water vapour pressure on the ice particle concentration.

     

A note on upper limits for hypothetic variation in the Newtonian constant of gravitation

Summary It has been demonstrated on the basis of recent astronomical, satellite and LLR data that the variations in the Newtonian constant of gravitation, if any, do not exceed5××10 ^–15 cy^–1 of its relative value.

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¶rt;a amuu u nmu a¶rt;u u a auu naa, m auauuaumau nm, u u um, n¶rt;m5×10 ^–15 mmu ^–1 mum au.

     

Czech hydrometeorological institute limited-area operational forecast model

Summary The CHMI LAOFM is used in the daily routine of the Central Forecasting Office of the Czech Hydrometeorological Institute and some special results are transmitted to the regional offices. The model works in the region of Europe and the North Atlantic, uses conservative finite difference schemes and two types of semi-implicit schemes that allow effective model structurization in terms of programming language. The basic philosophy of the model is described.

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¶rt; a zau mumuu unm zumzu umumm () ¶rt; z uz nza. m mam ¶rt;a zu nzam am amuu. z amam amu n u amu mamuz aa, un am , a a aa au. ama aum mu auau z n- , ma cam m nm a auuam mmauau nza. mam nuaa u u auauu.

     

Single- and inter-station transfer functions for non-synchronous geomagnetic arrays-II. the results of the field data analysis

Summary The theory of methods of computing single- and inter-station transfer functions in both the spectral and time domains was developed in paper[1]. Both approaches are applied to the variation data recorded at field stations along two non-simultaneous profiles traversing the eastern margin of the Bohemian Massif, where a zone of anomalous induction seems to mark an important geological boundary of formations with different histories of development. The results of both analyses are found to coincide within reasonable bounds of 20–30% in the principal induction characteristics.

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u m¶rt; ama ¶rt;-u -mau n¶rt;am u nma u am a ua am[1]. am nua m am a n¶rt;¶rt;a nu ¶rt; aaua ¶rt;aaum auau aumua a n mau ¶rt; u nu, nau m au aua,¶rt; aa a aa u¶rt;uu. a, u¶rt;u, mamau a¶rt;a ¶rt; ¶rt; ¶rt;uuau au umuu aumu. mam aau nma u am auam a 20–30% ¶rt; u¶rt;u naam.

     

The bayesian probabilistic prediction of the next earthquake in the ometepec segment of the mexican subduction zone

A predictive equation to estimate the next interoccurrence time () for the next earthquake (M6) in the Ometepec segment is presented, based on Bayes' theorem and the Gaussian process.Bayes' theorem is used to relate the Gaussian process to both a log-normal distribution of recurrence times () and a log-normal distribution of magnitudes (M) (Nishenko andBuland, 1987;Lomnitz, 1964). We constructed two new random variablesX=InM andY=In with normal marginal densities, and based on the Gaussian process model we assume that their joint density is normal. Using this information, we determine the Bayesian conditional probability. Finally, a predictive equation is derived, based on the criterion of maximization of the Bayesian conditional probability. The model forecasts the next interoccurrence time, conditional on the magnitude of the last event.Realistic estimates of future damaging earthquakes are based on relocated historical earthquakes. However, at the present time there is a controversy between Nishenko-Singh and Gonzalez-Ruiz-Mc-Nally concerning the rupturing process of the 1907 earthquake. We use our Bayesian analysis to examine and discuss this very important controversy. To clarify to the full significance of the analysis, we put forward the results using two catalogues: (1) The Ometepec catalogue without the 1907 earthquake (González-Ruíz-McNally), and (2) the Ometepec catalogue including the 1907 earthquake (Nishenko-Singh).The comparison of the prediction error reveals that in the Nishenko-Singh catalogue, the errors are considerably smaller than the average error for the González-Ruíz-McNally catalogue of relocated events.Finally, using the Nishenko-Singh catalogue which locates the 1907 event inside the Ometepec segment, we conclude that the next expected damaging earthquake (M6.0) will occur approximately within the next time interval =11.82 years from the last event (which occurred on July 2, 1984), or equivalently will probably occur in April, 1996.     

A3 ionospheric absorption measurements on 1539 kHz at Panská Ves

u¶rt;m mam uu u nu a¶rt;u m¶rt;3 (a na¶rt;u) a amm 1539 a amuu aa a nu¶rt; am 1978 — am 1981. u m nuau nu mma. a¶rt;am u¶rt;aa ma (a aumu) u a auau nu, u u aauu u an u u. numa u am au nu ¶rt; =60° na¶rt;am. au naa, m nu u um a a ¶rt;a ¶rt;m a nu¶rt;, nu a m n u nua nu mma am 1980.     

Magnitudes of detectable and localizable shocks in nw bohemia

Summary The effectiveness of recording seismic phenomena in the Kruné hory (Mts.) region in NW Bohemia by selected stations in the CSR, GDR and Poland has been estimated. Magnitude isolines of the weakest earthquakes, which can be localized and detected with an 0.9 probability, were calculated on the basis of the level of seismic disturbances at the individual stations and of the empirical dependence of the attenuation of seismic waves with distance.

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a a mum umauu uu u amu ¶rt; ana¶rt; uu uau mauu a mumuu , u a a uu n a m¶rt; mau u nuu auumu amau uu m amu u auma uuuu aum¶rt; a a mu, m mm 0.9 auuam u aum.

     

On the recent dynamics of the earth's surface of the Little Carpathians

a mam 10-mu u¶rt;au ¶rt;uauu nmu a anam. auum aam mua ¶rt;uu u nu amu uu, a , muu, u auauu n u mmu u uu umaa u ¶rt; nmu uuau.     

P-wave spectra of the Füzesgyarmat, eastern Hungary earthquake sequence

On 29–30 September 1996, an earthquake sequence occurred in the Füzesgyarmat region in eastern Hungary. The main shock had a magnitude of M_L = 3.2 and was felt with a maximum intensity 4 MSK. It was preceded by a foreshock with a magnitude of M_L = 2.8 and was followed, within six hours, by five aftershocks with magnitudes 2.1M_L 3.1. The dynamic source parameters of the Füzesgyarmat earthquake sequence have been derived from P-wave spectra of the Hungarian seismograph stations. The average of the obtained values at different stations shows that the main shock occurred on a fault length of 610 m, with relative displacement of 1.13 cm, stress drop of 7 bar and seismic moment of 3.96*10₂₁ dyne.cm. The main shock was small to yield data for a full mechanism solution and no reliable single fault plane solution could be obtained due to the low signal to noise ratio at the recording stations. The parameters of the foreshock are fault length of 560m, seismic moment of 2.09*10₂₁ dyne.cm, stress drop of 5.53 bar and relative displacement of 0.73 cm. The five aftershocks show source parameters similar to the foreshock stress drops (5.26 5.76 bar), fault lengths (415 L 600 m), seismic moments (8.36*10²⁰ M_o 2.31*10₂₁ dyne.cm) and relative displacements (0.52 0.91 cm).     

Theoretical wiese induction vectors for a three-dimensional prism in the vicinity of a vertical contact

Summary With the use of the method of boundary integral equations, a stationary approximation of the magnetotelluric field for a three-dimensional prism located in the vicinity of a vertical contact of two quarterspaces, whereby the applied electric field is oriented parallel with the vertical boundary, is solved. In combination with the solution for the perpendicular orientation of the exciting electric field, the theoretical Wiese induction vectors for three positions of the 3-D prism are calculated. It was shown that the centre of divergence of the Wiese vectors is displaced from the epicentre of the prism, namely, if the prism is close to the vertical boundary.

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nu m¶rt;a ¶rt;a u¶rt;a au n¶rt;maa mauaa annuau u nu¶rt; mam u¶rt; ama a¶rt;ummu¶rt; n ¶rt; nu, an uu mua¶rt; mama ¶rt; mmnmam. ¶rt;a mu n n¶rt;na¶rt;am ana naa mua ¶rt;au. uau aamua¶rt; a a aauua a nn¶rt;u ana¶rt; ¶rt;a¶rt; n ¶rt;aa m uum mmuu u¶rt;u m u ¶rt; m nu m nu. aa, m m a¶rt;u m u mum numa nu, ¶rt;¶rt;a nua nuaam mua ¶rt;au.

     

Analysis and optimization of wide-band force-balance seismometer responses

¶rt; aau n¶rt;am uu, umu,au mummu u ¶rt;uau ¶rt;uanaa mu um. am n a nmua amm aamumuu um ¶rt; au uu nuu. ¶rt;ma ummuu m¶rt; nmuau mu um a a¶rt;a an¶rt;u n n¶rt;am uu n nmu.     

The conditional probability of earthquake occurrence and the next large earthquake in Tokyo, Japan

The use of probability distribution ofrecurrence times as described by theexponential, Weibull and Rayleihgprobability densities form the core of theprobabilistic seismic prediction analysispresented in this paper. Using these threeprobabilistic models we derive threeformulas to calculate the conditionalprobability P(t|t) than an earthquakeevent will occur in the time interval (t, t+ t), provide that it has not occurredin the elapsed time t since the last largeearthquake (M 6.4) in the Tokyo area.This paper proposes a new method toestimate the time interval t foroccurrence of a new large earthquake inTokyo area. This time interval is measuredafter the elapsed time (t) since the lastlarge earthquake. To do this we use thethree formulas for the conditionalprobability P(t|t) and the criterionof the maximum conditional probability ofearthquake occurrence.Using a list of historical earthquakeswhich have occurred in the Tokyo area asgiven by Usami (1976, pp. 235–243), wefound that: (1) Using the exponentialmodel, it is estimated that a highlydamaging earthquake magnitude M 6.4, mayoccur before the year 2009.50, orequivalently before June 2009; (2) Usingthe Weibull model, it is estimated that thedamaging earthquake (M 6.4) may occurbefore the year 2129.80, or equivalentlybefore October 2129.     

On the rotational motion of deformable celestial bodies

¶rt;am au uu ¶rt; aam ¶rt;uu ¶rt;u ma; ¶rt;am am u ¶rt; a, ¶rt;a u¶rt; amua m uuu a; num n aaa auauu nm.