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Modal size distribution of the bottom sediments at the entrance of Tokyo Bay (Cooperative survey at the entrance of Tokyo Bay in 1959—Part 5)
320
Oceanographic Abstracts
and complete dissolution of the calcium carbonate shells is interpreted as an early diagenetic process. The author shows that, in cases of specific kinds of Foraminifera and of oogonies of Chara found gyttjae, the shape may survive in the form of resistant scleroprotein skins lining the chambers or enveloping the oogonies, respectively. JOLLIFFE, ]. P., (undated reprint). The use of tracers to study beach movements; and the measurement of littoral drift by a fluorescent technique. Rev. G~omorphol. Dynam., unnumbered pp. Un 616ment important des 6tudes g6omorphologiques de plages est le d6placement de vase, de sable et de galets sous l'influence des vagues et des courants. Ceci pose le probl~me de mat6rialiser et de mesurer de tels mouvements, en particulier celui de calculer la quantit6 de mat6riel affect6e par la d6rive littorale le long des plages naturelles. De tels renseignements sont 6viderrment de grande importance aussi bien pour des 6tudes purement scientifiques que pour la solution des probl~mes hydrotechniques pratiques. La premiere partie de l'article d6crit rapidement quelques-unes des techniques mises au point pour mat6rialiser le mouvement des d6bris sur les plages, particuli~rement l'emploi des isotopes radio-actifs. L'essentiel de l'article est consacr6 ~t I'utilisat!~3n des traceurs fluorescents, m6thode qui a 6t6 tr6s d6velopp6e et qui est largement utilis6e en U.R.S.S., et en particulier ~i une nouvelle technique fluorescente 61abor6e fi la station de Recherches Hydrauliques, qui permet de calculer le volume de la d6rive littorale ~t partir de la vitesse de diffusion des traceurs le long d'une plage. Des exp6riences de terrain ont montr6 que le transport littoral des galcts ~t Deal, Kent, change fr6quemment de direction et que la r6sultante est faible. Au cours des 21 premiers jours d'exp6rience le transport net a 6t6 de 720 tonnes vers le N tandis qu'au cours des 83 premiers louts d'exp6rience le transport net total a 6t6 de 1,310 tonnes vers le S. Le transport net le long de la c6te S du Dungehess a pfi 6tre fix6 fi 141,000 tonnes par an. A Rye, Sussex, le transport net de galets apr~s 21 semaines a 6t6 de 18,800 tonnes; des mesures poursuivies pendant 44 semaines ont permis d'6valuer le transport annuel/l environ 100,000 tonnes.
KAGAMI,H., 1962. Modal size distribution of the bottom sediments at the entrance of Tokyo Bay (Cooperative survey at the entrance of Tokyo Bay in 1959--Part 5). (In Japanese; English abstract). J. Oceanogr. Soc., Jap., 20th Ann. Vol.: 121-135. The present study of modal size analysis of the bottom sediments at the entrance of Tokyo Bay is an attempt to gain a better understanding of sedimentation and the composition of clastic sediments. One hundred and ten samples were collected between 6 and 545 m and a total of 334 modes was obtained from the samples. Distribution of the gravel and sand size was controlled by the displacement of sea level. A clear boundary for the depositional agency was found between fine sand and medium sand from an analysis of the distribution. On the shelf, medium sand was concentrated by the turbulence o f the surf, while fine sand was deposited by the orbital motion of the nearshore waves. Zonal distributions o f fine and medium sands show the sea level in various depths; 80 m, 40 m and 10 m. Distributions of mud size seem to be restricted by the oceanographic conditions and not by the depth alone. KAGAMI, H., N. NASU and M. [-[ORIKOSHI, 1962. Submarine topography at the entrance of Tokyo Bay (Co-operative survey at the entrance of Tokyo Bay in 1959--Part 2). (In Japanese; English abstract), d. Oceanogr. Soc., Jap., 20th Ann. Vol., 82-89. The area at the entrance o f Tokyo Bay (Urago Strait) between the Miura and Boso Peninsulas was studied. Here the bottom topography is characterized by Kannon-zaki cbannel and the Tokyo submarine canyon. Five different types of shelf channel are recognized from their different depths of termination. They are : Shelf channel, (1) from 5 m-15 m (2) from 20-35 m (3) from 20-55 m (4) from 20-70 m and (5) from 80-100 m. The order o f formation of the shelf channel is believed to be as follows: type (2) was formed first, then types (4) and (5) were formed during the regression; at the next stage types (3) and (l) were formed during transgressions. Six flat terraces are also recognised in this area: (i) an erosional terrace at 110 m (the shelf edge) (ii) the break in deposition 80 m below the Kannon-zaki channel, (iii) a depositional plane between 50 m and 60 m, (iv) an erosional terrace between 30 m and 40 m, (v) an erosional terrace at 20 m and (vi) a depositional plane at l0 m. KAWASAKI, N., 1962. On the easily soluble nitrogen from the mud in Matsushima Bay. (In Japanese; English abstract). Bull. Tohoku Reg. Fish. Res. Lab., No. 21: 87-92. The bottom mud in Matsushima Bay is classified by the particle composition into the following three types: (A) Mud mostly composed o f particles less than 55/~ in diameter, (B) Mud in which the particles larger than 125t~ exist in comparable amount with those under 55/~ in diameter. (C) Mud intermediate between these two. For the total easily soluble nitrogen there are significant differences between A and B and between B and C respectively. (2) The mud which contains abundant particles under 55/* in diameter has much easily soluble nitrogen. In examining the characteristic curve of' dehydration, it is observed that the mud of fine particles has a strong affinity for hydration, and thus has the power to keep the nitrogen.
Oceanographic Abstracts
and complete dissolution of the calcium carbonate shells is interpreted as an early diagenetic process. The author shows that, in cases of specific kinds of Foraminifera and of oogonies of Chara found gyttjae, the shape may survive in the form of resistant scleroprotein skins lining the chambers or enveloping the oogonies, respectively. JOLLIFFE, ]. P., (undated reprint). The use of tracers to study beach movements; and the measurement of littoral drift by a fluorescent technique. Rev. G~omorphol. Dynam., unnumbered pp. Un 616ment important des 6tudes g6omorphologiques de plages est le d6placement de vase, de sable et de galets sous l'influence des vagues et des courants. Ceci pose le probl~me de mat6rialiser et de mesurer de tels mouvements, en particulier celui de calculer la quantit6 de mat6riel affect6e par la d6rive littorale le long des plages naturelles. De tels renseignements sont 6viderrment de grande importance aussi bien pour des 6tudes purement scientifiques que pour la solution des probl~mes hydrotechniques pratiques. La premiere partie de l'article d6crit rapidement quelques-unes des techniques mises au point pour mat6rialiser le mouvement des d6bris sur les plages, particuli~rement l'emploi des isotopes radio-actifs. L'essentiel de l'article est consacr6 ~t I'utilisat!~3n des traceurs fluorescents, m6thode qui a 6t6 tr6s d6velopp6e et qui est largement utilis6e en U.R.S.S., et en particulier ~i une nouvelle technique fluorescente 61abor6e fi la station de Recherches Hydrauliques, qui permet de calculer le volume de la d6rive littorale ~t partir de la vitesse de diffusion des traceurs le long d'une plage. Des exp6riences de terrain ont montr6 que le transport littoral des galcts ~t Deal, Kent, change fr6quemment de direction et que la r6sultante est faible. Au cours des 21 premiers jours d'exp6rience le transport net a 6t6 de 720 tonnes vers le N tandis qu'au cours des 83 premiers louts d'exp6rience le transport net total a 6t6 de 1,310 tonnes vers le S. Le transport net le long de la c6te S du Dungehess a pfi 6tre fix6 fi 141,000 tonnes par an. A Rye, Sussex, le transport net de galets apr~s 21 semaines a 6t6 de 18,800 tonnes; des mesures poursuivies pendant 44 semaines ont permis d'6valuer le transport annuel/l environ 100,000 tonnes.
KAGAMI,H., 1962. Modal size distribution of the bottom sediments at the entrance of Tokyo Bay (Cooperative survey at the entrance of Tokyo Bay in 1959--Part 5). (In Japanese; English abstract). J. Oceanogr. Soc., Jap., 20th Ann. Vol.: 121-135. The present study of modal size analysis of the bottom sediments at the entrance of Tokyo Bay is an attempt to gain a better understanding of sedimentation and the composition of clastic sediments. One hundred and ten samples were collected between 6 and 545 m and a total of 334 modes was obtained from the samples. Distribution of the gravel and sand size was controlled by the displacement of sea level. A clear boundary for the depositional agency was found between fine sand and medium sand from an analysis of the distribution. On the shelf, medium sand was concentrated by the turbulence o f the surf, while fine sand was deposited by the orbital motion of the nearshore waves. Zonal distributions o f fine and medium sands show the sea level in various depths; 80 m, 40 m and 10 m. Distributions of mud size seem to be restricted by the oceanographic conditions and not by the depth alone. KAGAMI, H., N. NASU and M. [-[ORIKOSHI, 1962. Submarine topography at the entrance of Tokyo Bay (Co-operative survey at the entrance of Tokyo Bay in 1959--Part 2). (In Japanese; English abstract), d. Oceanogr. Soc., Jap., 20th Ann. Vol., 82-89. The area at the entrance o f Tokyo Bay (Urago Strait) between the Miura and Boso Peninsulas was studied. Here the bottom topography is characterized by Kannon-zaki cbannel and the Tokyo submarine canyon. Five different types of shelf channel are recognized from their different depths of termination. They are : Shelf channel, (1) from 5 m-15 m (2) from 20-35 m (3) from 20-55 m (4) from 20-70 m and (5) from 80-100 m. The order o f formation of the shelf channel is believed to be as follows: type (2) was formed first, then types (4) and (5) were formed during the regression; at the next stage types (3) and (l) were formed during transgressions. Six flat terraces are also recognised in this area: (i) an erosional terrace at 110 m (the shelf edge) (ii) the break in deposition 80 m below the Kannon-zaki channel, (iii) a depositional plane between 50 m and 60 m, (iv) an erosional terrace between 30 m and 40 m, (v) an erosional terrace at 20 m and (vi) a depositional plane at l0 m. KAWASAKI, N., 1962. On the easily soluble nitrogen from the mud in Matsushima Bay. (In Japanese; English abstract). Bull. Tohoku Reg. Fish. Res. Lab., No. 21: 87-92. The bottom mud in Matsushima Bay is classified by the particle composition into the following three types: (A) Mud mostly composed o f particles less than 55/~ in diameter, (B) Mud in which the particles larger than 125t~ exist in comparable amount with those under 55/~ in diameter. (C) Mud intermediate between these two. For the total easily soluble nitrogen there are significant differences between A and B and between B and C respectively. (2) The mud which contains abundant particles under 55/* in diameter has much easily soluble nitrogen. In examining the characteristic curve of' dehydration, it is observed that the mud of fine particles has a strong affinity for hydration, and thus has the power to keep the nitrogen.