Torsional oscillation of a homogeneous elastic spheroid

1962 ◽  
Vol 52 (3) ◽  
pp. 469-484 ◽  
Author(s):  
Tatsuo Usami ◽  
Yasuo Satô

abstract There are several causes for the observations of splitting of the spectral peaks determined from the free oscillation of the earth. In this paper, the splitting due to the ellipticity is studied assuming a homogeneous earth described by oblate spheroidal coordinates. Ellipticity causes the iTn mode to split into (n + 1) modes, while the earth's rotation causes it to split into (2n + 1) modes. 1/297.0 is adopted as the ellipticity of the earth. Numerical calculations are carried out for the fundamental mode (n = 2, 3, 4) and for the first higher harmonics (n = 1). The difference between the extreme frequencies for each value of n is 0.7% (n = 2), 0.5% (n = 3), and 0.4% (n = 4).

1964 ◽  
Vol 54 (5A) ◽  
pp. 1341-1347
Author(s):  
L. E. Alsop

Abstract Peaks corresponding to free oscillation of the earth have been observed in the spectrum of a seismogram written following the Kurile Islands earthquake of 13 October 1963 by a special long-period vertical seismograph, with a 60-second pendulum. The periods obtained for the free oscillations, which are all of the spheroidal type, and which lie in a range of 200 to 1000 seconds, are in good agreement with values previously obtained from the great Chilean earthquake of 22 May 1960. No spectral peaks are observed at periods shorter than 200 seconds. This same phenomenon was observed in the spectra of the Chilean earthquake, and it is probably associated with the properties of the vibrating medium, i.e., the upper mantle, rather than with the source.


1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.


1857 ◽  
Vol 8 ◽  
pp. 111-116 ◽  

The Trigonometrical Survey of the United Kingdom commenced in the year 1784, under the immediate auspices of the Royal Society; the first base was traced by General Roy on the 16th of April of that year, on Hounslow Heath, in presence of Sir Joseph Banks, then President of the Society, and some of its most distinguished Fellows. The principal object which the Government had then in view, was the connexion of the Observatories of Paris and Greenwich by means of a triangulation, for the purpose of determining the difference of longitude between the two observatories.


2021 ◽  
Author(s):  
Jean-Philippe Montillet ◽  
Wolfgang Finsterle ◽  
Werner Schmutz ◽  
Margit Haberreiter ◽  
Rok Sikonja

<p><span>Since the late 70’s, successive satellite missions have been monitoring the sun’s activity, recording total solar irradiance observations. These measurements are important to estimate the Earth’s energy imbalance, </span><span>i.e. the difference of energy absorbed and emitted by our planet. Climate modelers need the solar forcing time series in their models in order to study the influence of the Sun on the Earth’s climate. With this amount of TSI data, solar irradiance reconstruction models  can be better validated which can also improve studies looking at past climate reconstructions (e.g., Maunder minimum). V</span><span>arious algorithms have been proposed in the last decade to merge the various TSI measurements over the 40 years of recording period. We have developed a new statistical algorithm based on data fusion.  The stochastic noise processes of the measurements are modeled via a dual kernel including white and coloured noise.  We show our first results and compare it with previous releases (PMOD,ACRIM, ... ). </span></p>


Author(s):  
S. Tiguntsev

In classical physics, time is considered absolute. It is believed that all processes, regardless of their complexity, do not affect the flow of time The theory of relativity determines that the flow of time for bodies depends both on the speed of movement of bodies and on the magnitude of the gravitational potential. It is believed that time in space orbit passes slower due to the high speed of the spacecraft, and faster due to the lower gravitational potential than on the surface of the Earth. Currently, the dependence of time on the magnitude of the gravitational potential and velocity (relativistic effect) is taken into account in global positioning systems. However, studying the relativistic effect, scientists have made a wrong interpretation of the difference between the clock frequency of an orbiting satellite and the clock frequency on the Earth's surface. All further studies to explain the relativistic effect were carried out according to a similar scenario, that is, only the difference in clock frequencies under conditions of different gravitational potentials was investigated. While conducting theoretical research, I found that the frequency of the signal changes along the way from the satellite to the receiver due to the influence of Earth's gravity. It was found that the readings of two high-precision clocks located at different heights will not differ after any period of time, that is, it is shown that the flow of time does not depend on the gravitational potential. It is proposed to conduct full-scale experiments, during which some high-precision clocks are sent aboard the space station, while others remain in the laboratory on the surface of the earth. It is expected that the readings of the satellite clock will be absolutely identical to the readings of the clock in the Earth laboratory.


1969 ◽  
Vol 59 (5) ◽  
pp. 2079-2099
Author(s):  
John S. Derr

abstract All observations of the free oscillations of the Earth published through 1968 are weighted to produce a set of means and standard errors of the means. Fundamental orders 0 to 97 for spheroidal and 2 to 99 for torsional are treated, as well as many overtones up to order 49. Statistical tests indicate that some observations are path dependent at the 99 per cent confidence level. Comparison of these means and standard errors with published Earth models indicate that they form a consistent basis for inversion of free oscillation observations to infer Earth structures.


2019 ◽  
Vol 6 (2) ◽  
pp. 117-125
Author(s):  
Jailani Husain Saleh ◽  
Muhsinatun Siasah Masruri

Tujuan penelitian ini untuk (1) menguji perbedaan hasil belajar model earth science community dan group investigation (GI); (2) menguji perbedaan hasil belajar model earth science community dan GI pada siswa dengan gaya belajar visual; (3) menguji perbedaan hasil belajar model earth science community dan GI pada siswa dengan gaya belajar auditorial;  dan (4) menguji interaksi pengaruh antara model pembelajaran dan gaya belajar siswa terhadap hasil belajar geografi. Penelitian ini menggunakan metode kuasi eksperimen dengan desain faktorial 2x2. Populasi dalam penelitian ini adalah seluruh siswa SMA Negeri di Kota Kupang yang tersebar pada 12 sekolah. Teknik sampling yang digunakan adalah Simple Random Sampling dan terpilih 2 sekolah sebagai subjek penelitian. Hasil penelitian menunjukkan: (1) tidak terdapat perbedaan hasil belajar model earth science community dan GI pada aspek kognitif  dengan p = 0,374 > 0,05; pada aspek afektif dengan p = 0,645 > 0,05, dan pada aspek psikomotor dengan p = 0,969 > 0,05; (2) terdapat perbedaan hasil belajar model earth science community dan GI pada siswa dengan gaya belajar visual, pada aspek kognitif dengan p = 0,009 < 0,05; pada aspek afektif dengan p = 0,014 < 0,05 dan pada aspek psikomotor dengan p = 0,024 < 0,05;  (3) terdapat perbedaan hasil belajar model earth science community dan GI pada siswa dengan gaya belajar auditorial, pada aspek kognitif dengan p = 0,042 < 0,05; pada aspek afektif dengan p = 0,026 < 0,05 dan pada aspek psikomotor dengan  p = 0,017 < 0,05; (4) terdapat interaksi pengaruh model pembelajaran dan gaya belajar siswa terhadap hasil belajar geografi, pada aspek kognitif dengan p = 0,008 < 0,05, pada aspek afektif  dengan p = 0,004 < 0,05 dan pada aspek psikomotor dengan p = 0,006 < 0,05. AbstractThis study aims to test: (1) the difference in the learning outcomes through the earth science community and group investigation (GI) models, (2) the difference in the learning outcomes through the earth science community and GI models among students with the visual learning style, (3) the difference in the learning outcomes through the earth science community and GI models among students with the auditory learning style, and (4) the interaction of the effects of the learning models and the students’ learning styles on the geography learning outcomes. The study employed the quasi-experimental method with a 2x2 factorial design. The research population comprised all students of state senior high schools (SHSs) in Kupang city in 12 schools. The sampling technique was the simple random sampling technique and 2 schools were selected as the research subjects. The results of the study are as follows. (1) There is no difference in the learning outcomes between the students learning through the earth science community and GI models in the cognitive aspect with p = 0.374 > 0.05, in the affective aspect with p = 0.645 > 0.05, and in the psychomotor aspect with p = 0.969 > 0.05.(2) There is difference in the learning outcome through the earth science community and GI models among the students with the visual learning style in the cognitive aspect with p = 0.009  < 0.05, in the affective aspect with p = 0.014 < 0.05, and in the psychomotor aspect with p = 0.024 < 0.05. (3) There is difference in the learning outcome through the earth science community and GI models among the students with the visual learning style in the cognitive aspect with p = 0.042 < 0.05, in the affective aspect with p = 0.026 < 0.05, and in the psychomotor aspect with p = 0.017 < 0.05.(4) There is  interaction of the effects of the learning models and the students’ learning styles on the geography learning outcomes in the cognitive aspect with p = 0.008 < 0.05, in the affective aspect with p = 0.004  < 0.05, and in the psychomotor aspect with p = 0.006 < 0.05.


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