巻号一覧
26 巻 (1980)
- 4 号 p. 227-
- 3 号 p. 137-
- 2 号 p. 75-
- 1 号 p. 1-
26 巻, 1 号
選択された号の論文の6件中1～6を表示しています
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志知 龍一, 奥田 隆, 吉岡 茂雄1980 年 26 巻 1 号 p. 1-16
発行日: 1980/05/30
公開日: 2011/03/01
ジャーナル フリーA moving float type water-tube tiltmeter is designed for a reliable continuous record ing of secular ground tilt and earth tide observations. It is aimed in the present design that the detector should have such features as a wide dynamic range, a high resolution, an easy and secure calibration device, and very small mechanical drift. These are achieved by improving several defects associated with moving float type water-tube tiltmeters that have so far been developed. The diminishing effect, the difference between float movement and water level change, is markedly decreased by the adoption of a weak cross spring suspension for the fulcrum and a reduced mechanical magnification to decrease suction effect of the sensor. The diminishing factor in the present design, which is experimentally determined, is as small as less than 1%. A knife edge joint for connecting float rod to the arm can minimize the torque due to unbarance of the float metacenter which may cause spring creep or mechanical drift of the detector. Setting the hinge of calibration arm on the same axis of the fulcrum of the float arm, we can keep a constant sensitivity for a wide range, by which a highly reliable calibration is possible. Conversion coefficient for water level change has been obtained in a good ac curacy by this calibration mechanism. Although some errors (±2% at maximum) might be inherent in the case of absolute calibration, the relative accuracy between detectors has been found to be excellent under the routine observation.抄録全体を表示PDF形式でダウンロード (1542K) -
―振幅特性―石井 紘, 佐藤 俊也, 高木 章雄1980 年 26 巻 1 号 p. 17-25
発行日: 1980/05/30
公開日: 2011/07/05
ジャーナル フリー東北日本で見出された40km/yearの速度をもつ伝播するひずみの振幅特性について,前回の伝播特性にひき続き調べた.用いたデータは東北大学の5か所の地殼変動観測所の伸縮計によるもので,解析期間は1977年までで,前回より2年延長した.解析結果によると伝播するひずみの存在が一層明白になり,東北日本を横断し,日本海側の観測点にまで到達していることがわかった.また,年周変化の振幅と伝播するひずみの振幅や永年変化の振幅との関係を調べると,年周変化の振幅の大きいところは伝播性ひずみや永年変化も大きいことがわかり,振幅比と波長との関係はほぼ直線となることが明らかになった.抄録全体を表示PDF形式でダウンロード (749K) -
塚本 博則, 中川 一郎1980 年 26 巻 1 号 p. 26-34
発行日: 1980/05/30
公開日: 2010/09/07
ジャーナル フリー主要半日周潮であるM2およびS2分潮について,重力の潮汐変化におよぼす海洋潮汐の影響を,京都および水沢について計算した.その際,日本近海については,筆者が新たに作成した潮汐図を用いた.全世界の海洋については,M2分潮の場合には3種類の潮汐モデルを, S2分潮の場合には2種類の潮汐モデルを用いて,それぞれ計算を行なった. M2分潮の場合,海洋潮汐の影響量は計算に用いた全世界の潮汐モデルにより大きく異なり,それらのモデルの信頼度が低いことを示している.一方,S2分潮については,海洋潮汐の影響のほか,気象変化の影響や大気潮汐の影響などについても,詳細な検討を要することがより明白になった.抄録全体を表示PDF形式でダウンロード (922K) -
佐藤 忠弘, 大江 昌嗣, 佐藤 範雄1980 年 26 巻 1 号 p. 35-49
発行日: 1980/05/30
公開日: 2010/09/07
ジャーナル フリーThe tidal strain has been observed at Esashi Earth Tides Station which designed for earth tides observations. The station is located in the middle of Mt. Abara (780 m above mean sea level). Three extensometers made of quartz tubes 30 mm in diameter and 36, 36 and 51 m in length are installed in the vault in NS, EW and NW directions respectively. The detector of these extensometers is a differential transformer. Routine observations were begun in June 1979. Preliminary records from the end of April 1979 to the begining of June 1979 show the drifts of 4X10-8/month for NS and EW components and 2X10-8 for NW component. These drifts are probably of instrumental origin. The data of NS and EW components for the period during June to August 1979 are analyzed in two steps. The first one is the estimations of the amplitudes, their factors and phase differences of the observed data by least square fitting to the theoretical strain waves which are derived from the potential developed by Cartwright, Tayler and Edden. In these analysis the drift and non-tidal variations are removed by using Pertzev's filter. The standard deviation of a single observation has been found to be 2X10-8 in both components, which exceeds about 70 times the value as compared with the accuracy of the calibrations of the instruments or the reading errors. The second is the analysis of residuals obtained by subtracting the above estimated tidal strain waves from the original data. These residuals show broad shaped power spectra at the tidal bands and high powers at the low frequency band. The AR-response method is applied to the ahalysis of the relations between the residuals and the changes of the atmospheric pressure. The results suggest the existences of coupling between them but the physical interpretation is a problem of further investigations.抄録全体を表示PDF形式でダウンロード (2379K) -
石川 甲子男1980 年 26 巻 1 号 p. 50-58
発行日: 1980/05/30
公開日: 2011/03/01
ジャーナル フリーThe problem of geomagnetic secular variation at Kanozan has been reported already by the author. In this report, the geomagnetic monthly mean values of Kanozan Geodetic Observatory were compared with those of the other observatories (Memanbetsu, Mizusawa, Kakioka and Kanoya), during the period from Jan . 1961 to Dec. 1979. From the results, it seems that the secular variations of differences of the geomagnetic field between Kanozan and other observatories are larger than its normal values .抄録全体を表示PDF形式でダウンロード (592K) -
友田 好文, 藤本 博巳1980 年 26 巻 1 号 p. 59-65
発行日: 1980/05/30
公開日: 2010/09/07
ジャーナル フリーA new method is proposed for determination of both the magnetization of a vessel and geomagnetic daily variation by use of towing three proton magnetometers. Results of simulation show that geomagnetic daily variation can be measured within accuracy of 6±1 nT, if three precision proton magnetometers are towed 1300 m, 700 m, 100 m, apart from the vessel, measurement being carried out with accuracy of±0.05 n T every 2 min with ship's speed of 10 knots, and if accuracy of relative position fixing of the vessel is better than ±8 m in an hour.抄録全体を表示PDF形式でダウンロード (707K)
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