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Volume 3 (1956 - 1957･･･
- Issue 3-4 Pages 69-
- Issue 2 Pages 41-
- Issue 1 Pages 1-
Volume 3, Issue 3-4
Displaying 1-10 of 10 articles from this issue
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Seiti YAMAGUTI1957 Volume 3 Issue 3-4 Pages 69-71
Published: April 20, 1957
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSThe comparison of the change in the height of Bench Mark at Aburatubo resulted by Levelling Survey and that of Mean Sea-level, was already made, and reported in my recent paper [1]. In that case, pretty good parallelism was observed in the changing mode, but we must be obliged to perceive some discrepancy in the numerical value, that of mean sea-level being somewhat greater than that obtained by Levelling Survey.
In this case, the result is contrary, the value of the change of mean sea-level being smaller than that obtained by Levelling Survey in the same epoch. Thus, some question was thrown that the Standard Origin of Bench Mark at Miyakesaka meight has subsided in some amount, about 20 mm during the period of two years. It's value is not sounnatural, remembering that, it was 86 mm on the occasion of Great Earthquake of September 1, 1923.View full abstractDownload PDF (303K) -
Akira OTA1957 Volume 3 Issue 3-4 Pages 72-76
Published: April 20, 1957
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSComparing the results of the revision survey in Katanohara-region with those of the previous ones, following interesting phenomena were found. (1) The earth-movements, horizontal and vertical, accompanied by the earthquake, have different characters in every areal block divided by fault-lines. (ii) In each areal block, the mean vector of the horizontal displacements lies nearly in the direction of the maximum inclination of a plane ξ=a+bx+cy, where x, y are the horizontal rectangular coordinates of any triangulation point, is its vertical displacement and a, b, c are the constants to be determined by the method of the least siuares with respects to all the triangulation points in the area under consideration. (iii) With regards to the whole region of Katanohara, there exists linear correlation between the numerical values of the vertical displacements and those of the horizontal ones. The above facts seem to bold in the other resurveyed regions, such as in Fukui region suffered by the earthquake and both the coal-mine regions of North Kyushu and Fukushima.View full abstractDownload PDF (465K) -
-Practical Application to the Adjustment of Tenjinno Triangulation Net, Including 1 Base-line and 2 Laplace-stations-Tsutomu SHIMIZU1957 Volume 3 Issue 3-4 Pages 77-86
Published: April 20, 1957
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESSAs the sequel of the second paper showing a practical application of one of the working formulae for the Laplace residuals, the present paper is devoted to a numerical illustlation that the other working formula (3.5) in the first paper is effectively available for the adjustment of a regional triangulation-net. The sample adopted here is the revised “ Tenjinno ” triangulation-net, since it contains one remeasured base-line and two recently obseved Laplace stations, where the Laplace residuals are remarkably abnormal. By making use of the formula as not a condition but an error-equation, a set of the error-equations composed of the side-equations, the angle-equations and the Laplace-residual-equations, was adjusted so as to get the most probable values of variations of the geographical coordinates by means of the method of the least squares. The net-adjustment, however, was carried out in two different treatments (a) and (b), corresponding to two kinds of the angle-value, the one observed and the other station-adjusted, both of which have been applied with the same corrections of the normal section and of the plumb-line. The adjusted results were sosatisfactory that the mean error of an obsevation of unit weight in each case was considerably smaller than the one obtained from the usual figure net-adjustment, and furthermore the Laplace residuals were regarded as null in the range of the obsevational errors. For comparison, the third net-adjustment (c) was carried out, excluding only the Laplace-residualequations from the set of error-equations in the case (b). In this case, the adjusted Laplace residuals were reduced to -″1.88, -″1.63, - ″1.76 at “Taisho-yama” and -1″. 94, -1″ .73, -1″.86 at “ Mikuniyama ”, although the obseved ones were +6″.95, +5″.91, +4″.33; +2″.74, +5″.43, +8″.51 respectively. Whereas the adjusted values of the angles and the side-lengths proved, as expected, to be almost the same as those of the case (b). In the anthor's view, the case (a) may be the most favourable, and if the Laplace residuals are not given, the side-equations and the angle-equations correspondieg to the case (a) should be adjusted, though an error of orientation of the net will remaim as it is.View full abstractDownload PDF (1216K) -
Chikara SUGAWA1957 Volume 3 Issue 3-4 Pages 87-94
Published: April 20, 1957
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESSIt may be considered as indicating the inequality between A and B, principal moments of inertia in the equatorial plane of the Earth that the orbit of the Chandler term is elliptic. We established an approximate relation between the axial ratio (q/p) or the eccentricity of the Chandler ellipse and s, that is, (B-A)/(1-k)(2C-A-B):
q/p=(1+s/2)1/2
We deduced the inequality of two principal axes of the equator ellipse of the Earth by differentiating (A+B)/2=0.3310 a02M, Earth, and combining it with s. where a0 denotes the mean equatorial radius and M the mass of the Further as another method, we assumed the interior density of the Earth as homogeneous and solved the inequality of two principal axes of the equator ellipse from a quadratic equation as a function of s. Taking the polar coordinates from both the International Latitude Service and T. Hattori's unified system, we analysed the Chandler terms in the whole period 1900-52 and calculated the axial ratios and the orientations of minor axis of the Chandler ellipse. The inequalities of two principal axes of the equator ellipse deduced from the Chandler ellipses appeared to be of the same order as those deduced from gravity observations only in the periods 1906-19 and 1946-52 when the amplitudes of the Chandler term were large and the orbits were nearly circular. In the other periods, especially 1919-46, these inequalities seem tctake too large values, compared with those deduced from gravity observations.
We attributed, hitherto, the main origin of the inequality between A and B only to the inequality between two principal axes of the equator ellipse, but we should take consideration into the variation of the mechanical ellipticity or H= (2C-A-B)/2C. It is to be noted that the orientation of major axis of the equator ellipse changed abruptly since about 1919. It would be a remained problem whether the change of the figure or the distribution of the internal constitution of the Earth occurred really at about 1919.View full abstractDownload PDF (910K) -
Yoshibumi TOMODA, Toshio SENSHU1957 Volume 3 Issue 3-4 Pages 95-101
Published: April 20, 1957
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESS6) As is usually the case, the distribution of gravity values given at equidistant grid points on the earth's surface can not be regarded periodic with respect to the horizontal co-ordinate. A method for practical computations to be applied to these cases will begiven, with the hope to get rid of the awkwardness of the Fourier series method which implies the said periodic distribution.
According to the formula stated in § 5, the underground mass distribution p(×) is given by
Here φ(×) is the response function and is represented by
The values of φ(×) at grid points are in the Tables I and II. By use of the tables, the values of p(×) at the grid points of the subterranean plane are given by the following formula;
As an example, this method is applied to study the subterranean mass distribution corresponding to Bouguer anomalies given along the profile No. 17 in the East Indies.
7) If “Low-pass; high-cut” operation is to be carried out, the values of p(×)* at the grid points on the subterranean plane distributed at equidistant intervals of λ/2 are given by the following formula.
The values of φλ/λ* are also given in the Table I and II.
8) The vertical gradient of gravity (ag/az) or the deflection of the vertical (θ×) can begiven in the similar way as
where
The method is applied to calculate the anomalies in aglaz corresponding to the Bouguer anomales observed in Kyoto district .View full abstractDownload PDF (533K) -
1957 Volume 3 Issue 3-4 Pages 102-108
Published: April 20, 1957
Released on J-STAGE: September 07, 2010
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Triangulation and Base Line Measurement1957 Volume 3 Issue 3-4 Pages 109-111_2
Published: April 20, 1957
Released on J-STAGE: March 01, 2011
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1957 Volume 3 Issue 3-4 Pages 112-114_2
Published: April 20, 1957
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSDownload PDF (4901K) -
Geodetic Astronomy1957 Volume 3 Issue 3-4 Pages 115-117_1
Published: April 20, 1957
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSDownload PDF (2293K) -
Gravity Survey1957 Volume 3 Issue 3-4 Pages 118-122_1
Published: April 20, 1957
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSDownload PDF (2558K)
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