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Volume 7, Issue 2
Displaying 1-6 of 6 articles from this issue
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D. MIYADI1937 Volume 7 Issue 2 Pages 55-63
Published: 1937
Released on J-STAGE: December 11, 2009
JOURNAL FREE ACCESS -
II. Floating Islet Formation from the False BottomYoshine HADA1937 Volume 7 Issue 2 Pages 64-67
Published: 1937
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSThe writer observed that floating islets were derived from parts of the false bottom in one of many bog lakes in the Sphagnum-swamp of Kritappu on the eastern Pacific coast of Hokkaido.
In the bog lake, in which floating islets were found, are observed several water plants whose stems are creeping over the false bottom, that is, thence, usually suspended independently in water 30-50 cm in depth, while the true bottom is 1.0-1.5m in depth. The false bottom of this hog lake is well developed and becomes firm. On account of the action of decomposition gases accumulated under the false bottom, parts of it are risen to the water surface as floating islets. The colour of the false bottom is dark brown, but floating islets have the black surface, on which a few plants sometimes grow. The influence of the false bottom upon water temperature was not observed at the time of the reseach made in December, 1936.View full abstractDownload PDF (2611K) -
Yoshiaki KUSUKI1937 Volume 7 Issue 2 Pages 68-77
Published: 1937
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSHarutori is a gourd-shaped lake with a longer axis of 2000m and shorter axis of 200-400m, and is about 400m distant from the sea. The greatest depth of the lake is 8.5m. In the present paper are given the results of observations made on May 10, and July 13, 1936 respectively, and are also discussed the results obtained by Mr. Yoshine Hada, to whom I am de ply indebted.
The water of this lake was greenish brown and turbid, transparency being only 1m. Owing to the unequal vertical distribution of salts, the metalimnion was very well developed even during the periods of the autumnal and vernal circulations, the salinity of the bottom water being ten times that of the surface. The temperature of the bottom water always remained about 9°C throughout the year, while that of the surfarce varied from 0° to 17°C, or more (fig. 1). The water was alka-line in the epilimnion and neutral in both meta- and hypolimnion, , a marked depression being found in the stratum between 3.5 and 4.5m (table 1 and fig. 2) The surface Water was saturated with oxygen, while sudden decrease was taken place below 3m; below 4.5m it was replaced by hydrogen sulphide (fig. 3), of. which an enormous amount (665 mg/l) was detected in anaerobic zone where it was reduced from sulphate (table 3). The other biochemical stratifications are as follows : alkalinity and hardness increase in the metahmnion; anaerobic strata are completely devoid of phosphate, nitrate and nitrite, but there is a great amount of ammonia (103 mg/l) in the bottom water (table 4).
Such unrivalled amounts of H2S and ammonia dissolved in the hypolimhion and some other extraordinary properties observed in the lake caii he attributed to the permanent stagnation of the bottom water.View full abstractDownload PDF (373K) -
Masatake YAMASAKI1937 Volume 7 Issue 2 Pages 78-84
Published: 1937
Released on J-STAGE: June 12, 2009
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[in Japanese]1937 Volume 7 Issue 2 Pages 85-87
Published: 1937
Released on J-STAGE: June 12, 2009
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1937 Volume 7 Issue 2 Pages 87-88
Published: 1937
Released on J-STAGE: June 12, 2009
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