• On a condition for separating arguments of an implicit function.

      Owaki, N. (1959)
      Necessary and sufficient condition on a function of . N + M variables F(x1,···· , XM; P1,······, PN)=0 for the fact that the arguments can be separated info two groups, or the function may be transformed into a form f(x1,······, xM)=g(P1,······, PN) is given.
    • On the amendment of longitude of the former original point of Japan.

      Tsukamoto, Y. (1959)
      At the amendment of the original point of longitude of Japan from the old point (Naval Observatory .... the predecessor of the Tokyo Astronomical Observatory: 139° 44’30".3, enforced in 1886) to the new one (the Large Meridian Instrument of the Tokyo Astronomical Observatory: 139° 44’40".9) in 1918, the Hydro graphic Office notified the amendment value 10".6 in longitude, putting the interpretation that the above “Naval Observatory" meant the Large Meridian Instrument, whereas the Land Survey Department, the predecessor of the present Geographical Survey Institute, adopted the value 10".4, taking the Naval Observatory as Tittmann Point. Many materials, including the papers by Nakano (Deduction of the Longitude of the Tokyo Astronomical Observatory, Bulletin of the Hydrographic Office, Vol. I, 1917), and by Terao and Mizuhara (On the Longitude of the Tokyo Astronomical Observatory, Annales de l'observatoire astronomique de Tokyo, Tome I-3 me Fascicule, 11894), show that the old original point of longitude was definitely Tittmann Point. The charts, which were compiled during the latter half of the Meidi era, 1892-1912, presumably referred to Tittmann Point, because they seem to have used the astronomical data referring to the Japanese Standard Time or the geodetic data referring to the triangulation points of the Land Survey Department. In 1914, the longitude of astronomical observatory of the Hydrographic Office was determined to be 139° 46’.5".01, considering the longitude of the Large Meridian Instrument of the Tokyo Astronomical Observatory to be 139° 44' 30" .3. Therefore, the notification in 1918 gave erroneous amendment to most charts and hydrographic publications, except few charts which had been referred to the observatory of the Hydrographic Office. All descriptions about the original point of longitude compiled at the Hydrographic Office after 1918 are incorrect, including the data of longitude of the Large Meridian Instrument of the Naval Observatory shown on the I. H. B. Special Publication No. 24 a II, p. 235, 1932.
    • Methods of the amendment of the former charts compiled from the astronomical data.

      Tsukamoto, Yushiro (1959)
      With the completion of triangulation nets in Japan by the Land Survey Department in 1922, geodetic latitude and longitude were decided to be adopted for the compilation of chart instead of astronomical coordinates. Immediately after this decision, most of the astronomical survey data were damaged by fire of the great earthquake in 1923. Therefore, the actual reductions from astronomical to geodetic coordinates were carried out on the assumption that the triangulation points of the Hydrographic Office were coincident with those of the Land Survey Department, causing inevitably the following errors of some amount: (1) Error of astronomical observation spots amounts to 20”-30”( 1s-2s, 0.5 km -1 km) in some cases. (Observational errors, deviation of plumb line) (2) Since the triangulation data were adjusted to astronomical base line, overestimating the accuracies of astronomical observations, the resulting charts may contain some distortion in figure. (3) After the World War II, on some assumption, Kobayasi reamended the charts which had been prepared from the astronomical data. But these reamended charts may still have error of some 100 m. Methods of reamendment to these charts are: (i) The errors due to the error of astronomical base line: The corrections to longitude and latitude shall be obtained by the method of least squares so as to minimize the differences between values of longitude and latitude of control points on charts and those of the same points on the topographical maps of the Land Survey Department (present Geographical Survey Institute), on each chart. Then the meridians and parallels shall be shifted for these corrections without changing the figure, and magnification shall be corrected by photograph. (ii) The distortion of figure: , The distortion can only be rectified by optical method using the topographical map and aerophotograph, at a temporary measure.
    • Oceanographical and meteorological investigations at the disaster of the Nankai Maru.

      Suda, Kanji; Kita, Toyokazu (1959)
      The Nankai Maru, a 495-ton ferryboat in the northern areas of Kii Suido, was missed after emergency call at 1830 JST, January 26, 1958, and was found by echo sounding at 40 m deep and 5 km southwest of Nusima at 1600 JST, January 28. The causes of the disaster are considered to be as follows from meteorological and oceanographical standpoints of view: (1) It blew gusty wind of maximum instantaneous speed over instability line in warm sector of a developed extratropical cyclone. (2) Wind waves generated by warm gusty wind were superposed with their reflected waves by coastal cliff. (3) There existed strong ebb current at about the time of the disaster, which collided with small sea-ridge descending from west towards the disaster spot. In general, when southerly wind prevails, pyramidal waves become conspicuous along the course of ebb current from Naruto Kaikyo, and they extend as far as areas off Hinomisaki. These conditions were superposed, and awfully confused seas with pyramidal and mountainous waves caused, sufficient to make the disaster happen.
    • Lambert conformal conic projection and astronomical navigation.

      Sinzi, M. Akira (1959)
      Characters of celestial line of position plotted on chart of Lambert conformal conic projection, e. g. ICAO WAC one millionth, are investigated. Error of length of the intercept caused by neglect of change in the magnification along meridian, error of the position of intercept terminal caused by the difference between straight line intercept and great circle intercept, and error of the direction of position line due to the convergency of meridians give final effect of less than second order infinitesimal to the position of ship or aircraft, and are practically negligible even in high latitude or for high speed air navigation, in which cases the ordinary position line on Mercator chart gives serious error.
    • On the topographic representation in hydrographic survey, the writing left by the late Mr. Komukai.

      Komukai, Ryoshichi (1959)
      Since break of submarine topography can not be detected directly, its representation must influenced according as the accuracy of survey and the character of the topography itself. Discussing these influences in this treatise, we have obtained following conclusions: The limits for representation by the scales of obtained geomorphological charts are almost equal for scales 1/8,000,000 and for 1/4,000,000. However, in the charts of larger scales, 1/500,000,1/50,000,1/20,000 to 1/10,000, and 1/3,000 to 1/1,000, topographies corresponding to various kinds of classification can be represented according as the scale. Dimensions of various topographies classified to “ large”,“small”,and “micro” topographies can be represented as the power of ten, i.e., for example, widths of terraces of the order of magnitude of 100 km in the case of large, 10km for small, and 1km for micro-topographies. Thus, dimension is represented as exponential function of scale. Also the span of isobaths is represented as an exponential function of scale.
    • Dynamic instability of divergent flow in a two-layer ocean.

      Hikosaka, Shigeo (1960)
      This is a preliminary paper for stability of a divergent flow. A very simple model is considered which shows the most crude approximation of the currents structure in the ocean. The effect of horizontal divergence for instability of laminar flow is studied and the results are compared with the results of non-divergent flow.
    • Geomagnetic surveys on sea by aircraft and ship.

      Kato, Yoshio; Utashiro, Shinkichi; Matuo, Masayuki; Takagi, Akio; Terajima, Makoto; Ito, Miyoshi (1960)
      In accordance with the resolution adopted at the XI th General Assembly of I. U. G. G., 1957, the program of magnetic surveys on sea has been progressed in Japan. For the aeromagnetic survey on sea, an airborne magnetometer with saturable inductor was developed by the Tohoku University team of the writers, and was put to practical surveys in Boso-district in February, 1958, around Osima Island (Izu) area in July, 1958, and in the Izu Syoto (Islands) in August,1959. The results of the first and second surveys were reported previously. The third survey was carried out by " Beachcraft No. 502 " of the Maritime Safety Board, with flight elevation of 3000 m above the sea level, measuring the vertical component of the earth's magnetic field to clarify that the most remarkable anomaly was associated with volcanoes on the Izu Syoto. For the magnetic survey at sea surface, a shipborne magnetometer, designed by the Tohoku University team of the writers, was employed on a survey ship Takuyo of the Hydrographic Office around the Sagami Nada near Izu Hanto (Peninsula), in January, 1960. The heart of this magnetometer is a saturable inductor mounted on a gimbal system. In order to avoid the magnetic disturbance by the vessel, the instrument was hung at about 40-meter depth beneath her body. From results of the survey, two remarkable anomalies were observed around Ito and Okinoyama, respectively. It is found that the anomalous anomaly near Ito is associated with submarine volcanoes, and the· anomaly around Okinoyama belongs to the submarine topographic configuration. We also studied the magnetism of a steel vessel. In this paper, the general feature of magnetic fields around an iron ship is investigated, especially, from the standpoint of detecting it magnetically. Magnetic moment of the steel vessel Takuyo was obtained from the results of magnetic survey around her body by assuming the vessel as a uniformly magnetized prolate spheroid.
    • Studies on abnormal refraction over sea surface,I. observation of dip of sea horizon.

      Sinzi, M. Akira; Owaki, Naoaki (1960)
      As one of the studies on abnormal refraction over sea surface, made in Sirahama in February, 1959, we have also observed dip of sea horizon under favorable conditions for arising mirage. It is found that the classical linear empirical formula still holds between Th-Tw , h and dip, where Th, Tw and h mean the temperatures at the observer and of surface water, and the observer's height from the sea surface, respectively. The coefficients in the formula are obtained to take rather larger values than usually adopted. Dependence of dip on water vapor is examined and it is regarded to affect dip. It is also found that there exists a strong correlation between Th-To , and Th-Tw, where To is the temperature in the air immediately above the sea surface. A new formula for dip is suggested.
    • Edge waves induced by a radially spreading long wave and its damping due to the irregularity of coast.

      Ogawa, Kiheiji (1960)
      First, the generation of edge waves by a cylindrically spreading long wave and,next, its damping due to the irregularity of coast are treated in two cases of the epicontinental bottom configuration such as is treated by Sezawa.
    • On the local character of the geomagnetic pulsation, Pc.

      Utashiro, Shinkichi (1960)
      It is well known that Pc type pulsation occurs simultaneously in the world-wide region. The author studied the results observed by induction magnetometers at the Japanese four stations (Memanbetsu, Onagawa, Simosato and Kanoya). From the results of the studies, local inequality of Pc was found. Period or mode of Pc changes with latitude, and amplitude of Pc becomes larger with increasing latitude. Such local Pc type pulsation may be produced by the hydromagnetic oscillations in the region between the inner Van Allen Belt and ionosphere. Two mode of oscillations exist in this region, toroidal and poloidal oscillation. In the higher latitude the poloidal and toroidal oscillations are observed; in the lower latitude only the poloidal oscillation is observed. Therefore, local Pc occurs frequently in the higher latitude than in the lower latitude.
    • On the possible role of horizontal divergence to meanders of a wide current in a stratified ocean.

      Hikosaka, Shigeo (1960)
      Expansion of H. Stommel's theory for the meanders of a very wide current in a stratified ocean is studied. And it is shown that if the thickness of the lower layer is limited or the current exists there, the meanders may occur in the ocean of which upper current is smaller than Stommel's critical value.
    • Numerical values of the integrals of the specific formula.

      Owaki, N. (1960)
      Tables for the numerical figures of the specific functions (please refer to the original)are constructed for the values of the argument x from 0.0 to 8.0, respectively.
    • On the geomagnetic post-perturbation.

      Utashiro, Shinkichi (1960)
      The character of the Geomagnetic Post-Perturbation, shows a decreasing in the daily means of the magnetic horizontal intensity at many observatories during several days following magnetic storm, is illustrated in this paper. As the general tendency, the amplitude of the Post-Perturbation decrease proportionally with latitude except near the auroral zone. Also, the decrease value of Post-Perturbation on the stations of same longitude shows rather good agreement with each other. From these results, it can be assumed that the current system of Post-Perturbation, is determined from several observatories in low and middle latitude except high latitude observatories, is similar to equatorial ring current system. Therefore the radius of equatorial ring current system by Post-Perturbation able to be determined from world wide distribution of magnetic intensity of Post-Perturbation. Analyzing much data in the worldwide, the results was obtained that the radius is about 20,000 km. It was found that this radius is equivalent to that of Van Allen Belts.
    • Radio chemical analysis of strontium 90 and cesium 137 in sea water.

      Higano, Ryoji; Shiozaki, Masaru (1960)
      In order to investigate the contamination of sea water by artificial radjoactive materials in adjacent sea of Japan, Sr-90 and Cs-137 are separated from sea water sample of large volume which were collected at 4 stations in the Pacific Ocean, and analysis radiochemically. Sr is analyzed by Nitric acid method. Cs is absorbed to Nickel Ferrocyanide to separate from large volume water and is analyzed by ammonium phosphomolybdate method and by chloroplatinate method.
    • Core sample of bottom sediment at the northern part of Nakanose,Tokyo Bay.

      Iwabuchi, Yoshio; Aoki, Naoaki; Oshite, Kei; Hori, Shoichi; Sato, Takahiro (1960)
      The rate of sedimentation of Tokyo Bay is estimated by means of core analysis as 2.4 cm per 10 years. This rate was determined on the basis of the key bed of scoria layer derived from the Hoei eruption of Mt. Fuji. And, chronological changes of sedimentary environment through the core have been found by the analyses of grain size, minerals, pollen, diatom, and foraminifera.
    • Approximate boundary layer of the β-plane with special application to western boundary current.

      Ogawa, Kiheiji (1960)
      Approximate theory of the boundary layer is extended to the β-plane for homogeneous barotropic flow with examples of special flow pattern.
    • On the galactocentric distance of the Sun and its rotation velocity.

      Sinzi, M. Akira (1960)
      Two methods to evaluate R0 and w0 , using radial velocities and proper motions of cepheids, are introduced: (i). R0 can be derived by evaluating R0 Δ w against Δ R for various values of R0 under the condition that R0 Δ w =0 at R=R0, and (ii). w0 can be derived by evaluating w against Δ R, and the ratio of Ro Δ w to Δ w gives R 0. Using Irwin's data on cepheids, above methods yield R0= 8.6kpc,_and wo= 29.0 ± 9.0 km sec-1 kpc-1.These values are favorable for excluding the inconsistency existing between the available values of R0 w0 and Vo.
    • On the bottom sediments off Akita.

      Tamaki, Misao; Ao, Shunji; Sato, Takahiro (1960)
      In summer, 1958, bottom sediments were dredged at 366 stations off the coast of the Akita Prefecture. The bottom is very rugged at the northern and southern parts, and is flat monotonously at the middle. Almost of sediments are sandy. The median map shows parallel contours and grain size changes regularly from coast to offing with some irregularities. Md-Depth relation shows abrupt change of grain size at the depths of about 10 m and 55 m. Md-So relation shows clear decrease of sorting coefficient at 2.3-3.0 MdΦ.