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Volume 6 (1960 - 1961･･･
- Issue 4 Pages 121-
- Issue 3 Pages 75-
- Issue 2 Pages 31-
- Issue 1 Pages 1-
Volume 6, Issue 1
Displaying 1-6 of 6 articles from this issue
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By IZUO OZAWA1960 Volume 6 Issue 1 Pages 1-5
Published: February 10, 1960
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSIn order to observe the ground-strain due to the tide generating force of the earth, it is neccesary to record measurably the linear strains, which are as large as 10-10. For that purpose, it should not only make longer the base line on the ground, but also magnify extremly the relative displacement of the both edge-points of the base line. A new type of high sensitive extensometer of which magnifier is a Zöllner suspension type tiltmeter is devised. In the mechanism of the extensometer, a super-invar rod that the length is constant, is put parallel with the base line, and an edge of the rod is fixed on one edge of the line so that the relative displacement of the unfixed edge of the rod and the other edge of the line may be transformed into the inclination of a support of the Zöllner pendulum. Cosequently, the pendulum of the tiltmeter rotates magniloquently. And also the rotaional angle of the pendulum is enlarged and recorded with an optical lever on a photographic printing paper. The extensometer has a sensitivity in the order that is higher than the formerly using one, and the sensitivity is able to be perfectly controlledat will. As the sensitivity to the linear strain is more than 100 times as large as that of the extensometer as to the ground-tilting, the influence from the tilting may be neglected. Then, the linear strains of the earth's surface in earth tide is observed with this extensometer at Osakayama Observatory, and is obtained the following analyzed values that are sbtructed the influence of ground-tilting, in the prime vertical direction, M2-component: 0.689 x 10-8 cos (2t -0.9°), O1-component: 0.705 x 10-8 cos ( t-19.1°).And also the records (of the ground-strain) which are observed with new type extensometer are compared with them which are observed with other types'. In these records, the interresting phenomena which are generated within a short hour, are found.View full abstractDownload PDF (2129K) -
Takeshi DAMBARA1960 Volume 6 Issue 1 Pages 6-9
Published: February 10, 1960
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESSCombining the gravity anomaly and the deflection of the plumb line, one can deduce the position and the depth of the centre of gravity of the anomarous mass which is assumed to be isolated from other anomarous masses. In order to let the deflection of the vertical be corresponding with Bouguer anomaly, it must be corrected by two procedures; one is to reduce the reference ellipsoid to the mean geoid, that is, to convert the deflection of the vertical to those of the plumb line, and the other is the correction of topography . After such procedures, the position and the depth of the anomarous mass which has influence upon the Kui Peninsula, are determined successfully, as shown in Fig. 3 and Table III.View full abstractDownload PDF (538K) -
Akira JITSUKAWA, Hirokazu TAJIMA1960 Volume 6 Issue 1 Pages 10-11
Published: February 10, 1960
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSSecular variation of scale value constant of No. 60 Worden-gravimeter was measured. Between the period from 1952 to 1954 with its old spring, any variation in constant was observed. (Fig. 1). Between the period from 1955 to 1958 with its new spring, variation of about 0.23% year was observed. (Fig. 2 and Fig. 3).View full abstractDownload PDF (184K) -
Izumi YOKOYAMA, Hirokazu TAJIMA1960 Volume 6 Issue 1 Pages 12-13
Published: February 10, 1960
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSGravity value at top of Mt. Fuji measured in 1880 by MENDENHALL by the use of the gravity pendulum is 978, 86 gals. In 1957 gravity value at the same position was measured by the use of the Worden gravimeter and the value of 978, 877 gals was obtained. Mean density of Mt. Fuji calculated from this value is 2.63 gr/cm3.View full abstractDownload PDF (234K) -
—Europe and North Africa Regions—Yasuo SHIMAZU, Tetsuyuki SAKATA, Fumihiko ABE1960 Volume 6 Issue 1 Pages 14-17
Published: February 10, 1960
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESSThe Bouguer and isostatic isogam maps of Europe and North Africa complied by J. W. de Bruyn are analyzed based upon a three-dimensional sin xix method. The maps of the relief base of the crust (Fig. 1), deflections of the vertical (Fig . 2) and geoidal undulations (Fig. 3) are presented. The densities of the crust and the subterranean mantle are assumed to be 2.67 and 3.27 gr/cm3 respectively. The depth of condensation is taken as 30 km. The undulations in geoidal heights are relative to the point (about 43°N, 5°E) which is marked by the cross in Fig. 3. Discussions of the calculated results are not presented here.View full abstractDownload PDF (291K) -
Hitoshi TAKEUCHI1960 Volume 6 Issue 1 Pages 18-21
Published: February 10, 1960
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSThe periodic variations in the eccentricity of the Vanguard satellite 1958 aL are considered to be due to the presence of a third tonal harmonic in the earth's gravitational field. In the present paper, a theory is proposed to explain this gravity anomaly by the convection currents in the earth's mantle. The fluid velocity, temperature variation and stress difference involved in the convection current are of the order of mm/year, degree and 107 dyne/cm2, respectively.View full abstractDownload PDF (438K)
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