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Découverte d'attapulgite dans les sédiments profonds du golfe d'Aden et de la mer Rouge
Oceanographic Abstracts
129
" bourrage." The magnitude of this maximum is given by (27rls)/T, in which Is represents the impulse of the breaking wave. Whereas, when A < 0"6, the maximum shearing force is caused, in most cases, at the peak of the "gifle," its magnitude being given by P,n [ 1 -- (?t/2cr) sin (2zrr')/r'], in which Pm represents the peak pressure of the " gifle," and r ' represents ~/T. In the case of the wall of horizontal block construction, the shearing force theoretically supposed to act on anyhorizontal construction plane is expressed in similar expression as in the monolithic wall; the o n l y difference from the expression in the monolithic wall is that a new dimensionless parameter hx appears in place of A, ~1 being a ratio characteristic of the dimensions of the upper part of the wall above the construction plane under consideration multiplied by a ratio rnl/(ml ÷ m2), in which ml and ms represent the mass of the upper part above the plane and that of the part below the plane, respectively, of the wall. When the ratio mx/(m~ + m2) is small and when most of the shock pressure is exerted upon the upper part of the wall, the value of Az reduces. Then, the shearing force at the " g i f l e " becomes larger than that during the " bourrage." HEEZEN BRUCE C.) WLADIMIR D. NESTEROFF, AGNf~SOBERLIN et GERMAIN SABATIER, 1965. D6couverte d'attapulgite dans les s6diments profonds du golfe d'Aden et de l a m e r Rouge. C.R. Acad. Sci., Paris, 260 (22): 5819-5821. Des s6diments recueillis par 1000/t 2000 m de fond darts le golfe d'Aden montrent une forte teneur eta calcite ( - 50%) et une faible teneur en quartz ( - 5 ~ ) . La fraction argileuse est, pour une large part, form6e d'attapulgite. On retrouve l'attapulgite, quoique en plus faible quantit6, dans les s6diments d6pos6s dans l'axe de l a m e r Rouge. HEPPER B. T., 1965. Pre-moult changes in the structure of the integument of the lobster, Homaras vulgaris. Rapp. Proc. Verb., Cons. Perm. Int. Expl. Mer., 156: 7-14. The necessity for knowing the frequency of moulting in the lobster, Homarus, in population studies involving growth rates is discussed. The available methods for determining frequency of moulting in lobsters are examined, and it is concluded that none is entirely satisfactory. Pre-moult changes in the integument of captive lobsters are described from histological studies, and the time in days pre-moult at which these changes were observed is used to suggest a means of determining the frequency of moulting with reasonable accuracy at moderate cost. The results are discussed in the light of previous similar work on lobsters and other crustaceans.
HINO MIKIO, 1964. Studies on wave generation by wind and roughness of the sea. 1. Coastal Engineering in Japan, 7: 1-10. M o d e m theories on the generation of waves by wind and wave spectrum are applied to an investigation on the wave characteristics (including fetch) and the roughness of the sea surface. The theoretical results are compared with experiments already published by other workers. Fairly good agreements are shown. HmOTA REImHIRO and TAKUO ESDO, 1964. On primary production in Bingo-Nada of Seto Inland Sea. II. Primary production and plankton. (In Japanese; English abstract). J. Fac. Fish. and Animal Husbandry, Hiroshima Univ., 5 (2): 519-535. Also in: Contrib. Mukaishima Mar. Biol. Sta., Hiroshima Univ., 1963-1965 (77). Quantitative examination of living plankton was carried out at two stations (BG-1 and BG-2) in Bingo-nada (central part of the Seto Inland Sea). This paper considers the quantitative relationship between the primary production and the standing crop of planktonic diatoms. The total cell number of diatoms increased remarkably in and after April, 1963 at BG-2 (especially at the 0-5 m depth). Species composition of diatoms varied so much from month to month that dominant species alternated frequently. Acartia clausi and Oithona nana dominantly occurred only at BG-2. From the difference of dominant copepod species the environmental conditions at BG-2 seems to he more inshore in character than those at BG-1. The quantitativ~ relationship b&ween primary production and living planktonic diatoms was discussed by correlating the following variables : the total cell number, the total photosynthesis, the photosynthesis per cell, the chlorophyll a content per cell, and the photosynthesis per unit chlorophyll a. There is tendency for the chlorophyll a content per cell to drop as the total cell number increases. The chlorophyll a content per cell is high when the total number of cells is sparse. The photosynthetic activity of chlorophyll a seems to be greater in the warmer season, and less in the colder season. The photosynthetic activity per cell fluctuates according to the variations in both the chlorophyll a content per cell and the photosynthetic activity of chlorophyll a. In most cases, however, its fluctuation was cause by the variation in the chlorophyll a content per cell. Accordingly, there a tendency was observed indicating that the photosynthetic activity per cell is less when the total cell number increases and becomes greater when the diatom cells are sparse. In most examples, an increase in total photosynthesis was observed concurrently with a marked increase in the total cell number. In such cases, the photosynthetic activity per cell was comparatively weak, but the cumulative photosynthesis was high because of the large number of cells. On the other hand, there were cases in which an increase in total photosynthesis was observed despite a rather scanty cell number; in such cases the photosynthetic activity per cell was very strong. These several interrelationships persisted irrespective of the species composition o f planktonic diatoms. Accordingly, it seems that an increase or
129
" bourrage." The magnitude of this maximum is given by (27rls)/T, in which Is represents the impulse of the breaking wave. Whereas, when A < 0"6, the maximum shearing force is caused, in most cases, at the peak of the "gifle," its magnitude being given by P,n [ 1 -- (?t/2cr) sin (2zrr')/r'], in which Pm represents the peak pressure of the " gifle," and r ' represents ~/T. In the case of the wall of horizontal block construction, the shearing force theoretically supposed to act on anyhorizontal construction plane is expressed in similar expression as in the monolithic wall; the o n l y difference from the expression in the monolithic wall is that a new dimensionless parameter hx appears in place of A, ~1 being a ratio characteristic of the dimensions of the upper part of the wall above the construction plane under consideration multiplied by a ratio rnl/(ml ÷ m2), in which ml and ms represent the mass of the upper part above the plane and that of the part below the plane, respectively, of the wall. When the ratio mx/(m~ + m2) is small and when most of the shock pressure is exerted upon the upper part of the wall, the value of Az reduces. Then, the shearing force at the " g i f l e " becomes larger than that during the " bourrage." HEEZEN BRUCE C.) WLADIMIR D. NESTEROFF, AGNf~SOBERLIN et GERMAIN SABATIER, 1965. D6couverte d'attapulgite dans les s6diments profonds du golfe d'Aden et de l a m e r Rouge. C.R. Acad. Sci., Paris, 260 (22): 5819-5821. Des s6diments recueillis par 1000/t 2000 m de fond darts le golfe d'Aden montrent une forte teneur eta calcite ( - 50%) et une faible teneur en quartz ( - 5 ~ ) . La fraction argileuse est, pour une large part, form6e d'attapulgite. On retrouve l'attapulgite, quoique en plus faible quantit6, dans les s6diments d6pos6s dans l'axe de l a m e r Rouge. HEPPER B. T., 1965. Pre-moult changes in the structure of the integument of the lobster, Homaras vulgaris. Rapp. Proc. Verb., Cons. Perm. Int. Expl. Mer., 156: 7-14. The necessity for knowing the frequency of moulting in the lobster, Homarus, in population studies involving growth rates is discussed. The available methods for determining frequency of moulting in lobsters are examined, and it is concluded that none is entirely satisfactory. Pre-moult changes in the integument of captive lobsters are described from histological studies, and the time in days pre-moult at which these changes were observed is used to suggest a means of determining the frequency of moulting with reasonable accuracy at moderate cost. The results are discussed in the light of previous similar work on lobsters and other crustaceans.
HINO MIKIO, 1964. Studies on wave generation by wind and roughness of the sea. 1. Coastal Engineering in Japan, 7: 1-10. M o d e m theories on the generation of waves by wind and wave spectrum are applied to an investigation on the wave characteristics (including fetch) and the roughness of the sea surface. The theoretical results are compared with experiments already published by other workers. Fairly good agreements are shown. HmOTA REImHIRO and TAKUO ESDO, 1964. On primary production in Bingo-Nada of Seto Inland Sea. II. Primary production and plankton. (In Japanese; English abstract). J. Fac. Fish. and Animal Husbandry, Hiroshima Univ., 5 (2): 519-535. Also in: Contrib. Mukaishima Mar. Biol. Sta., Hiroshima Univ., 1963-1965 (77). Quantitative examination of living plankton was carried out at two stations (BG-1 and BG-2) in Bingo-nada (central part of the Seto Inland Sea). This paper considers the quantitative relationship between the primary production and the standing crop of planktonic diatoms. The total cell number of diatoms increased remarkably in and after April, 1963 at BG-2 (especially at the 0-5 m depth). Species composition of diatoms varied so much from month to month that dominant species alternated frequently. Acartia clausi and Oithona nana dominantly occurred only at BG-2. From the difference of dominant copepod species the environmental conditions at BG-2 seems to he more inshore in character than those at BG-1. The quantitativ~ relationship b&ween primary production and living planktonic diatoms was discussed by correlating the following variables : the total cell number, the total photosynthesis, the photosynthesis per cell, the chlorophyll a content per cell, and the photosynthesis per unit chlorophyll a. There is tendency for the chlorophyll a content per cell to drop as the total cell number increases. The chlorophyll a content per cell is high when the total number of cells is sparse. The photosynthetic activity of chlorophyll a seems to be greater in the warmer season, and less in the colder season. The photosynthetic activity per cell fluctuates according to the variations in both the chlorophyll a content per cell and the photosynthetic activity of chlorophyll a. In most cases, however, its fluctuation was cause by the variation in the chlorophyll a content per cell. Accordingly, there a tendency was observed indicating that the photosynthetic activity per cell is less when the total cell number increases and becomes greater when the diatom cells are sparse. In most examples, an increase in total photosynthesis was observed concurrently with a marked increase in the total cell number. In such cases, the photosynthetic activity per cell was comparatively weak, but the cumulative photosynthesis was high because of the large number of cells. On the other hand, there were cases in which an increase in total photosynthesis was observed despite a rather scanty cell number; in such cases the photosynthetic activity per cell was very strong. These several interrelationships persisted irrespective of the species composition o f planktonic diatoms. Accordingly, it seems that an increase or