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Volume 14 (1969)
- Issue 4 Pages 125-
- Issue 2-3 Pages 39-
- Issue 1 Pages 1-
Volume 14, Issue 4
Displaying 1-7 of 7 articles from this issue
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Naomi FUJITA, Keiichiro MADOKORO1969 Volume 14 Issue 4 Pages 125-131
Published: September 30, 1969
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESSThe modified difference method is derived for the analysis of the monthly mean sealevel. This method consists of taking the difference of monthly mean sea-levels between the standard and reference stations in a same region and cancelling the annual variation. The irregularities left after the correction of this method are rather reduced and are estimated as about ± 15 mm. In the Niigata Earthquake; 1) It seems to be difficult to detect the extraordinary changes before the Earthquake, though the slight change of linear variation might exist around 1959. 2) The displacement of the crust at the Earthquake are motionless in Iwasaki, a score of centimeters down in Nezugaseki and a few centimeters down in Wajima, being based on Kashiwazaki. 3) The difference of linear variations between Nezugaseki and Kashiwazaki might change before and after the Earthquake. Such phenomenon is found at Kushimoto before and after the Nankaido Earthquake. In the Tokachi-Oki Earthquake, 1968; 1) It seems likely that the crust around Hachinohe and Miyako subsided by several centimeters comparing with that of Onahama. 2) It is possible that the abnormal change appeared in 1966 might be related with the oceanographic conditions.View full abstractDownload PDF (587K) -
Masanori SAITO1969 Volume 14 Issue 4 Pages 132-134
Published: September 30, 1969
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSTheories for the hydrostatic figure of the earth were reviewed. It was found that the combination of equations adopted by de Sitter was not reasonable, and that Khan's solution was not a hydrostatic one at all.View full abstractDownload PDF (359K) -
-1. Construction of Baseline Networks-Ryuichi SHICHI, Kumizi IIDA1969 Volume 14 Issue 4 Pages 135-143
Published: September 30, 1969
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSThe base-line networks for repeatable surveys with a Geodimeter VI (No. 6485) were constructed in Inuyama area for detecting tectonic movements. The structures of the base-line networks, their combination set for surveys and observational accuracy are discussed. The surveys were conducted three times, the results of which show the principal strain similar to that resulting from the observations by continuous recording system for detecting Crustal movements. The principal strain was found to be +(6-9)×10-6 in the direction of N 125°-130° W and - (12-20)×10-6 in the direction of N 35°-40° W during the period from August 1967 to May 1968. The principal stress inferred from the occurrence mechanisms of small shocks which were observed in Inuyama area has a tendency of coincidence with that inferred from the extension and contraction of the principal strains above mentioned.View full abstractDownload PDF (912K) -
Kumizi IIDA, Ryuichi SHICHI, Hiroshi MATSUURA1969 Volume 14 Issue 4 Pages 144-155
Published: September 30, 1969
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESSAfter the installation of the instruments: Water-tube Tiltmeter; Ishimoto silica clinograph; silica extensometer, at Inuyama Crustal Movement Observatory in 1966, the continuous observation of crustal deformation has been carried out. This report is the results of 14 months- observation. It was found that the maximum principal strain was 0.6×10-6 in extension and 0.5×10-6 in contruction; areal dilatation was -0.2- +0.6×10-6 and maximum shearing strain was 1.6×10-6. The changes in inclination was also found to be in the order of 1.8×10-6 rad. The direction of extension of the principal strain seems to be corresponding to the geologic structure in Inuyama district. The change in areal dilatation has a reciprocal to that of the maximum shearing strain . The noise accompaning precipitation is comparatively large compared with the secular change in crustal deformation. However, the foundamental clue to the removal of this noise effect on crustal deformation was obtained. The mechanism of this noise appearance is presumably understood by considering the geologic structure in this area.View full abstractDownload PDF (1258K) -
Takehisa HARADA1969 Volume 14 Issue 4 Pages 156-158
Published: September 30, 1969
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSThis report is a continuation of two reports[1, 2] published previously.
An arbitrary geodetic network has been adjusted strictly on the surface of a reference ellipsoid by using the Universal Program, whose program name is TO 16 G 4 for the electronic computer NEAC-2206 in the Geographical Survey Institute. It was necessary until now that the position of a station is given at least as a known station in a network.
The Universal Program has been improved so as to be available in a case such as all stations are unknown, too. In such a case Σpivi2 = min. is solved under conditions nΣi=1Nicosψiδλ = 0, nΣi=1Miδψi = 0, where pi and vi are the weight and the small correction of individual observed value, Mi and Ni are the radii of curvature in meridian and prime-vertical at a station Pi (longitude = λi East +, latitude = ψi), δλi and δψi are the small corrections of λi and ψi. If we give known old values of the station Pi to λi and ψi, (Ni cos &psii;δλi, Miδψi) is a displacement-vector Vi for a period from old survey to new survey. The solution of ΣV = 0 is found by means of another computation process that is not so elegant as the method above, too. It is the method that we give a station in a network its old known position and perform the computation of net-adjustment and find an average displacement-vector and subtract it from individual displacement-vector. Fig. 1 is a same geodetic network used in [1] for the purpose of explainning concretely the Universal Program. These two solutions are tested on the network. Input data in the latter method in that the position of a station P4 is known is shown in the first _??_, and other input data in the elegant former method by that solution of ΣV = 0 is obtained directly is shown in the second _??_. The difference between these two input data is that there are known stations or there are not known stations in them. The results of the two methods are shown in Table I. The values in the brackets in Table I are found briefly by additional manual computation. Perfect coincidence of two results proves that the Universal Program has been improved without making a mistake.View full abstractDownload PDF (328K) -
Naomi FUJITA1969 Volume 14 Issue 4 Pages 159-161
Published: September 30, 1969
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSDownload PDF (216K) -
[in Japanese]1969 Volume 14 Issue 4 Pages 162-164
Published: September 30, 1969
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSDownload PDF (509K)
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