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Volume 24 (1968)
- Issue 6 Pages 265-
- Issue 5 Pages 195-
- Issue 4 Pages 147-
- Issue 3 Pages 87-
- Issue 2 Pages 41-
- Issue 1 Pages 1-
Volume 24, Issue 4
Displaying 1-6 of 6 articles from this issue
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Kikuo KATO, Yasushi KITANO1968 Volume 24 Issue 4 Pages 147-152
Published: August 31, 1968
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSThe solubility of amorphous silica in sea water is about 85mg-SiO2/l at 20°C, which is less than that in distilled water (about 113mg-SiO2/l). The dissolution rate seems to be controlled by the amount of silica gel present and its solubility. Silica gel in sea water is transformed to dissolved silica at a much faster rate than in distilled water. A maximum value of dissolved silica is observed during the process of dissolution under no abrasion condition, when the dissolution rate is very large. The differences in the solubility and in the dissolution rate of amorphous silica in distilled and in sea water cannot be explained by the difference in pH values of the waters but seem to be due to the salts present in sea water.View full abstractDownload PDF (929K) -
Shizuo TSUNOGAI, Masakichi NISHIMURA, Syu NAKAYA1968 Volume 24 Issue 4 Pages 153-159
Published: August 31, 1968
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSCalcium and magnesium in sea water have been determined. In the western North Pacific, the average concentrations are 0.4049g/kg for calcium and 1.2684g/kg for magnesium in the water of 19.00‰ chlorinity and their ratios to chlorinity are 0.02131 for calcium and 0.06676 for magnesium. The ratio of calcium to chlorinity not only increases with depth but also varies among the surface water-masses. Thus, the ratio can be used as a water-mass tracer. The magnesium-chlorinity ratio shows no such a tendency.View full abstractDownload PDF (1004K) -
Yoshikazu YAMAMOTO1968 Volume 24 Issue 4 Pages 160-166
Published: August 31, 1968
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSThe minor elements Ni, Co, Cu, Zn, Pb, Cd, Cr, V, Mo, Zr and Ga were studied in 21 samples of shallow-water deposits from West, South and North Bays of Nanao. Ni (av. 14±5ppm), Co (av. 6±2ppm), Zn (av. 51±7ppm), V (av. 39± 6 ppm) and Mo (av. 0.5±0.3 ppm) were not so much concentrated in these deposits as in pelagic deposits, but only Ga (av. 12±3ppm) shows concentration similar to that in pelagic sediment. It is characteristic of these deposits that Pb (av. 55±6ppm) and Zr (av. 101±46 ppm) are notably abundant in them, compared with those of shallow-water deposits from all the coasts of Honshu, Japan, Korean coast and Gulf of Paria. The constancy of Co/Ni ratios was found in these deposits and red clays despite large difference in abundance of these elements in them. There are positive correlations between the contents of Ni, Zn and Ga and content of Al, and also between the contents of V and S.View full abstractDownload PDF (980K) -
Koji HIDAKA1968 Volume 24 Issue 4 Pages 167-172
Published: August 31, 1968
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSBy a transformation of hydrodynamical equations of viscous liquid, expressions were derived, by which both the speed of upwelling and sinking, and the vertical profile of the coefficient of vertical eddy viscosity can be computed at the same time. For numerical computation, data of pressure gradients and of the velocity components of horizontal currents and their horizontal derivatives are necessary. As data satisfying this requirements direct current measurements carried out with Roberts meters in the Swan Song Expedition 1961 in the Eastern Tropical Pacific are available. Resulting coefficient of vertical eddy viscosity which must be positive by nature, very often has negative sign, probably, due to vanishing of the denominator in the solution of simultaneous equations and consequent predomination of errors from various other sources.
As possible sources of these errors, mention was made of the inadequateness of the accuracy in current measurement, the possibility of large fluctuations of ocean currents at or close to the Equator and the fact that the ocean current measurements and the hydrographic observations for evaluating mass distribution in the area were not made simultaneously.View full abstractDownload PDF (863K) -
Fumihiro KOGA1968 Volume 24 Issue 4 Pages 173-177
Published: August 31, 1968
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSThree nauplius stages of Undinula vulgaris, the first, the third and the fifth stages, were studied. The nauplius is oval in out-line in early stages, becoming more elongate with each successive stage. The dorsoventral flexure in the posterior portion of body curves ventrally. The nauplius of U. vulgaris can be distinguished from those of other species of the family Calanidae by the structure of appendages in the respective stages.View full abstractDownload PDF (641K) -
Storms Surges on the Coast of the Japan SeaIchiro ISOZAKI1968 Volume 24 Issue 4 Pages 178-190
Published: August 31, 1968
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSStorm surges on the eastern coastal line of the Japan Sea are studied. In contrast with the Pacific coast, extraordinary destructive surges hardly develop there because shallow waters such as bays or a continental shelf are comparatively small. Generally speaking, the effect of atmospheric pressure is roughly hydrostatic, and northeasterly winds cause the descent of sea level and southwesterly winds the ascent of it since the shore line runs from southwest to northeast. However, the fluctuations of sea level are different remarkably according to the course of atmospheric disturbances as well as topography of the coast. Case studies are made in detail for four storms which took different courses. In some cases we can clearly recognize a typical external surge which follows the storm considerably later at a very low speed of about 3-4m/sec along the continental shelf from the southern entrance of the sea to Noto Peninsula. Its low speed is explained by assuming a shelf wave of Robinson's type. A curious fact that the sea level sinks before the arrival of the storm is also discussed.View full abstractDownload PDF (3723K)
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