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Volume 31 (1985)
- Issue 4 Pages 295-
- Issue 3 Pages 247-
- Issue 2 Pages 163-
- Issue 1 Pages 1-
Volume 31, Issue 2
Displaying 1-8 of 8 articles from this issue
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Chuichi KAKUTA, Kachishig SATO1985 Volume 31 Issue 2 Pages 163-176
Published: July 25, 1985
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSFluctuations of the Earth's rotational speed and local residuals in astronomical obser vations might be related with motions of the solid Earth. In order to study these relations a comparison is made between variations of strain, which are observed at the Esashi Earth Tides Station (9h25m20.5s E, 39s08'53" N) and UT2-TAI, published by BIH, residuals of time, UTO-UTC, and latitude of the PZT and Danjon Astrolabe at Mizusawa (9h24m31.5sE, 39°08'03"N) published by the IPMS, since Tune 1979. By using one year running mean and adjusting a constant rate, we obtain a good correlation between variations of the Earth's rotational speed and UTO-UTC of the Mizusawa PZT with the East-West component of strain. The residuals of latitude shows a phase lag of about 3 month to variations of the North-South component of strain. These relations suggest that variations of the Earth's rotational motions may be related with those of the density distributions near the Earth's surface.View full abstractDownload PDF (1281K) -
Isao NAITO, Naokichi KIKUCHI1985 Volume 31 Issue 2 Pages 177-188
Published: July 25, 1985
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSA numerical estimation of leveling refraction errors from surface boundary layer data based on so-called Monin-Obukhov theory is presented. The computations are done from two temperatures and a wind speed at different heights assuming the roughness length to be known. The distance of line of sight is taken to be 50 m and slope to be 1/100. The results of estimation show that the leveling refraction errors have good relationships to the variations of temperature difference at two heights above and below the instrument in near adiabatic (neutral) condition but not in diabatic (unstable and stable) conditions. These facts suggest that a method for estimating leveling refraction error based on the planetary boundary layer theory including temperature gradient in the diabatic conditions is needed in the fields having mountains and strong seasonal variations of climate like Japan.View full abstractDownload PDF (1212K) -
Takao TABEI, Kunio FUJIMORI, Yutaka TANAKA1985 Volume 31 Issue 2 Pages 189-201
Published: July 25, 1985
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSContinuous observations of Crustal movements have been carrying out since 1977 at Ikuno, which is located in the northwestern part of Kinki District, with four horizontal components of extensometer, four components of horizontal pendulum type tiltmeter and water-tube tiltmeters of which four pots are specially arranged to form a quadrate. These special arrangements of observational instruments enable a high-accurate analysis of ground strains and tilts by changing the combination of components used for analysis. Thus reliability of observed values are easily estimated from the com parison of results obtained from different combination of observed components. An attempt to detect the reliable crustal movements is shown in this paper. Secular strains and tilts observed and analyzed by the new methods indicate remar kable changes during the period from the late 1978 to the early 1980 and also in the mid-1981. These changes are characterized by the mode that rotation of axis of principal strains coincides with change in direction of maximum tilt. The patterns of horizontal strains obtained from geodetic survey indicate that Ikuno is situated in the middle of three characteristic block, so it seems that different stress changes in each block alternately affect the crustal movements observed at Ikuno quasi periodically.View full abstractDownload PDF (1568K) -
Kazuo KOMAKI1985 Volume 31 Issue 2 Pages 202-211
Published: July 25, 1985
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSThe variances and covariances of the least squares estimates of baseline vectors which are obtained from delay and delay rate observations with VLBI have been esti mated by the analytical method. And the optimum distributions of radio sources for delay and delay rate observations have been investigated,View full abstractDownload PDF (697K) -
Shujiro NISHI1985 Volume 31 Issue 2 Pages 212-219
Published: July 25, 1985
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSIn the vicinity of Omaezaki seasonal crustal motion was observed by levelings which have been repeated four times every year since 1981 To clarify the detail of this motion, new leveling net adjacent to the line between Kakegawa and Omaezaki was established. In this paper, to analyze the time dependent data obtained from these levelings, an adjustment method in which the velocity of vertical motions and the amplitude of annual variation of each leveling bench mark are treated as unknowns is presented with the results.View full abstractDownload PDF (640K) -
Yukio HAGIWARA, Hirokazu TAJIMA, Sadakatu IZUTUYA, Ko NAGASAWA, Ichiro ...1985 Volume 31 Issue 2 Pages 220-235
Published: July 25, 1985
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESSPrecise gravity surveys have been repeated twenty-seven times in the Izu Peninsula since December 1974. During this period we have observed gravity changes accompanied with vertical crustal movements. This paper describes the outline of the observed gravity changes as well as their accuracies.View full abstractDownload PDF (1717K) -
Naosuke SEKIGUCHI1985 Volume 31 Issue 2 Pages 236-240
Published: July 25, 1985
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSA computational method of the prediction of the polar motion for the time scale about a month is proposed. In this method, the BIH's definitive values of the pole posi tions are used as data, and the Chandler component of the predicted polar motion is expressed as a part of circle. The standard deviation of the predicted positions is 0".0130 for 1978-1985.View full abstractDownload PDF (573K) -
Yukio HAGIWARA1985 Volume 31 Issue 2 Pages 241-242
Published: July 25, 1985
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSThe cross-correlation function of two surface spherical harmonics is expressed in an analytical form with Eulerian angles.View full abstractDownload PDF (137K)
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