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Volume 2 (1955 - 1956･･･
- Issue 3-4 Pages 79-
- Issue 2 Pages 47-
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Volume 2, Issue 3-4
Displaying 1-11 of 11 articles from this issue
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[in Japanese]1956 Volume 2 Issue 3-4 Pages 79-82
Published: March 20, 1956
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSThe first-order levelling and triangulation were performed from 1952 to 1955 in the Sourthern Part of Hokkaido after the great earthquake of "Tokachi-oki", Mar. 1952. As the old survey was carried out about fifty years ago, the difference between new and old surveys not only represents the deformation accompanying the earthquake, but also comprises the secular variation of the land. Vertical displacements of the crust is perspicuous in the Fig. 2. It seems that in Hokkaido the land is inclined to the south-east on the whole. The Fig. 6 shows that the horizontal displacements of the triangulation stations are small.View full abstractDownload PDF (372K) -
Kinichi ONO1956 Volume 2 Issue 3-4 Pages 83-89
Published: March 20, 1956
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSIn the cross-sea levelling carried out at the straits of Tsugaru, the zenith distances were observed simultaneously at two opposite stations, and the relative height was calculated by the usual tangent formula. The formula holds only if the refraction coefficients be identical in one direction and the opposite (Kij= Kji). Such assumption, however, may hardly be true in general, especially in such long sight-lines as in the case of the straits of Tsugaru (about 20 Km). Taking the fact into account, we put Kji=Kij+ΔK, and the refraction coefficients Kij and Kji were respectively evaluated in two independent ways: one way was made use of the refraction formula, into which the meteorological data were introduced, while the other was applied Eggert's formulae, in which the refraction coefficients were represented by the power series of the relative height, instead of his original form. As a result, the corrections to be applied to the apparent relative height were found to be+13 cm and+19 cm respectively.View full abstractDownload PDF (674K) -
Takehisa HARADA1956 Volume 2 Issue 3-4 Pages 90-92
Published: March 20, 1956
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSBy examing the night observations of the first order triangulation, it was found that the difference between the values of any angle obtained by observing it at two different times t and t+τ(τ<20 minutes) seemed to belong to a normal distribution with its stan dard deviation proportional to the square root of the time interval (τ), independent of the angle orientation and of the initial time t.View full abstractDownload PDF (299K) -
[in Japanese]1956 Volume 2 Issue 3-4 Pages 93-103
Published: March 20, 1956
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSThe revision of triangulation survey was carried out with regard to 106 triangulation points distributed in the northern part of Kyfisyu. As the results, the horizontal displacements of these triangulation points were worked out with reference to several points surrounding the area. These reference points are situated in the region covered with layers of older geological formation; i.e., the mesozoic and Paleozoic formations and the granitic layer, underlain the layers of the tertiary formation. The vertical displacements of these triangulation points were also worked out with reference to the bench-marks nearby, of which the heights and their changes were measured by means of precise levels. The horizontal and vertical displacements thus worked out are due to the time interval from 1897 to 1954. The distribution of the vertical displacements shows that there are several centres of subsidence, as shown in Fig, 3. These subsidence centres appear to be closely related with mining the coal field, the sinking exceeding 7 m at most. As for the horizontal displacements, we notice that (i) the amounts are larger at the points where the vertical downward displacements are large, and that (ii) the directions of the displacements are rather at random. Remarkable deformation of the earth's surface such as reported in the present manuscript is thought as has been caused by underground mining. But it may be a matter of further discussion whether the deformation has been caused simply by underground excavation.View full abstractDownload PDF (897K) -
Kazuo MURAOKA, Akira TSUDA, Kazuo KITADA1956 Volume 2 Issue 3-4 Pages 104-107
Published: March 20, 1956
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSThe optical multiplication of distance by means of Fabry-Perot etalons is capable by spectroscopic method even when the factor of multiplication is twenty under normally incident ray. Its application leads to a very precise topography of the reflecting surface.View full abstractDownload PDF (1629K) -
Masahisa TORAO1956 Volume 2 Issue 3-4 Pages 108-110
Published: March 20, 1956
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSUsing 166 data of the deflection of verticals in Japan observed during the period from 1884 to 1950, a spheroid that most closely fits to the geoid in Japan was determined; the equatorial length being longer by 363 meters as compared with Bessel's ellipsoid and the ellipticity being 297.33. The absolute deflection of the vertical at the standard datum, A zabu, Tokyo, was obtained as ξ0=+10."40 and η0= -7 ."87. When we solved the absolute deflection having the shape and size of the spheroidunchanged as that of Bessel's, Eo and η0 were obtained as +9."81 and -7."44 respectively. Using the residuals from this solution, inclination of the geoid in Japan relative to the spheroid was roughly estimated.View full abstractDownload PDF (279K) -
Hidewo HIROSE1956 Volume 2 Issue 3-4 Pages 111-118
Published: March 20, 1956
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESSIf there be an error in the co-ordinates of an observing site, in the meaning of geo centric geometry, the position of a celestial body at a finite distance as observed from such a site may be proved to be affected by the error, when compared with the correct geo centric position of the body. The present paper deals with the inverse problem of this effect and shows that such errors can be deduced from a series of astronomical observa tions, meridisan transits of the Moon and occultation observations, as compared with the corresponding series of standard observations.
By this method the author obtained the corrections to the adopted values of the longitude and latitude of the Japanese datum point as follows:
Δλ=-21″.5+5″.4 Δψ= +12″.6±2″.6.
These corrections can reduce the geodetic system of Japan to the “geocentric-geometrical” system. These corrections, together with a correction, da= +0.59+0.37 km recently obtained by the author, to the value of the equatorial radius of Bessel's spheroid, which is adopted in Japan, seems to be able to explain the famous “gap” between the triangulation nets of the Manchurian system and those of the Korean system, found in their boundary area. From the residuals in the explanation, one can suspect that a further correction in azimuth, ΔA= +5″, should exist in the Korean triangulation system as a whole, which might likely have raised in the course of extension to the said boundary area from the Tsushima. (The Editor).View full abstractDownload PDF (2068K) -
Shigetaka IIJIMA1956 Volume 2 Issue 3-4 Pages 119-122
Published: March 20, 1956
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSIt is unavoidablly necessary at present to know in advance the longitude variation due to polar movement, for precise time service and for some other researches. In order to get the predicted values of x and y for one year from the results which were obtained by observation during the preceding several years, a method of calculation is proposed which, is obtained by a synthetic treatment in vector representation under an assumption that both amplitude and phase in the Chandler component and those in the annual one are almost constant during the years in question. An application of the method to a series of known data proved a pretty satisfactory prediction.View full abstractDownload PDF (530K) -
Naoichi KUMAGAI, Etsuo ABE1956 Volume 2 Issue 3-4 Pages 123-126
Published: March 20, 1956
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSIn the previous paper (I), the present authors calculated the vertical attraction Am of Mt. Fuji at the summit stations S1 and S2 taking into account the exact form of the mountain. The values of A, n thus obtained are 105.37, 0 mgal for the station S1 and 105.02, 0 mgal for S2, where p is the mean density of the mountain under consideration. In this paper, value of Am is deduced from the gravity value obtained by Mendenhall at the summit, and, combining this value of Am with the result mentioned above, the value of pis calculated. The calculation should be made in consideration of the vertical attraction, C+A, at the summit station, due to the subterranean mass anomalies which may be expected from the theory of isostasy and subsurface geologic structure. Disregarding the effect of C*+A, the mean density of the mountain is 1.75 or 1.78, which seems to be too small. An approach to the estimation of C+A at the summit stations would be made possible by utilizing the already published data of Bouguer anomalies at Kofu, Shizuoka, Numazu and Odawara situated around and near the mountain, and the vertical gradients of gravity at these stations, which will be easily determined if we make use of a Worden gravity meter.View full abstractDownload PDF (595K) -
Bunkiti IMAYOSI1956 Volume 2 Issue 3-4 Pages 127-129
Published: March 20, 1956
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSThe Decca Navigator System was applied to the survey operation in Tugaru Strait. The stability of the pattern obtained in this survey was 5/1000 of a lane. Using this equipment, the measurement of the velocity of propagation of radio wave is possible. For this purpose, the phase differences of the radio waves are observed either extensions of the base line. The result obtained is 299, 771.9 km/sec, which is little different from the value of the velocity of 299, 700 km/sec presumed in forming the patterns.View full abstractDownload PDF (342K) -
[in Japanese]1956 Volume 2 Issue 3-4 Pages 130-131
Published: March 20, 1956
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSDownload PDF (289K)
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