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A hydraulically actuated safety device
628
Oceanographic Abstracts
RUSNAK GENE A., ROBERT L. FISHER and FRANCIS P. SHEPARD, 1964. Bathymetry and faults of G u l f o f California. In: Marine geology of the Gulf of California, a symposium, Amer. Ass. Petrol. Geol., Memoir. (Edited by VAN ANDEL T. and GEORGE G. SHOR JR.), 3: 59-75, The numerous cruises of Scripps Institution vessels to the Gulf of CaLifornia between 1957 and 1963 have provided thousands of miles of new sounding lines that have made possible an extensive revision of the earlier bathymetric charts. The fault scarps suggested by earlier soundings are now well confirmed, and also th~ indications of right-lateral movement with resulting tensional fractures. Several newly discovered northeast-trending deeps have been discovered. En echelon faults diagonal to the general trend of the Gulf are apparently a southward extension of the San Andreas system. Displacements of the order of 160 miles appear to have taken place between the two sides of the G u l l with a break in the crust forming the central G u l f with its near-oceanic depths. The end of the Baja California Peninsula is thought to have been located originally in the vicinity of Banderas Bay on the mainland. Two types of elevations occur in the Gulf : Those forming islands and banks along the western margin and consisting largely o f ' granite,' and central highs, most of which do not reach the surface and contain basic volcanics. The continental shelves are very narrow or nonexistent on the west side of the Gulf but fairly broad on the east, especially to the south of Mazatlfin. The eastern shelves appear to be of a depositional character. RUSSELL R. C. H. and J. R. C. DYKE, 1963. The direction of net sediment transport caused by waves passing over a horizontal bed. Int. Ass. Hydraul. Res., Congr., Lurid., 1963: 41-46. Results are presented of experiments to determine when the net transport of sediment comprising the horizontal bed of a laboratory channel is towards, and when away from, the beach. The direction of the net transport and its discharge rate were determined by observations on the movement of fluorescent tracers. It was found that when the bed was rippled, short waves produced transport towards the beach, and long waves transport away from the beach, the tendency to transport away from the beach being greater as the depth of water was reduced. Transport on a bed that was not rippled was invariably towards the beach. It is shown theoretically that it is not possible to make a wave model, with water as the fluid, in which the net transport is correctly reproduced. Every combination of conditions needs to be studied separately. RUSSELL R. C. H., n . E. NEWMAN and K. W. TOMLINSON, 1963. Sediment discharges measured by continuous injection of tracers from a point. Int. Ass. Hydraul Res., Congr., Lond., 1963: 69-76. A method is presented for obtaining the intensity of a sediment discharge by continuous injection of tracer sediment at a point near the bed, followed by sampling for surface concentration on a line across the flow. Experiments are described that were carried out in a wave-basin to determine the accuracy of the method and also to determine how close to the injection point the sampling could be done. A method is suggested for the way in which this minimum distance--3 ft under the particular conditions used~should be scaled up to obtain the prototype figure. SACHS P. L., 1964. A hydraulically actuated safety device, d. Mar. Res., 22 (1): 105-109. A hydraulically-actuated safety device has been built and has proved effective in reducing accidental, premature op~ration of oceanographic samplers. It consists of a cylinder, a piston, and a shear actuated by the piston. Increasing hydrostatic pressure acting on one side of the piston shears a pin at a predetermined depth, thus arming instruments sensitive to sudden motion. SAIJO Y. and T. KAWASHLMA, 1964. Primary production in the Antarctic Ocean. J. Oceanogr. Soc., Japan, 19 (4): 190-196. Studies on primary production were made in the Antarctic Ocean, between 40°W and 100°E, from December 1961 to February 1962. At ten stations, chlorophyll-a and photosynthetic rates were determined for surface samples, as well as the depth of Secchi disk reading. At thirty-five other stations only the chlorophyll-a in surface water was determined. At most of the stations the chlorophyll-a contents were very low (i.e. 0.02 to 0.22 mg/m a) except at a few stations where higher values (i.e. 0-3-0.6 g/m s) were obtained. The photosynthetic rates determined by the 14C technique under optimumlight conditions ranged from 0-06 to 0"80 mg C/m3/hr, and the mean value of photosynthesis per unit amount of chlorophyll was 1.22 mg C/mg chl./hr. The daily primary production beneath a unit surface, calculated from the above results and light data ranged from 0-01 to 0'15 g C/m2/day. After consideration o f t b e high concentration of nutrients in the sample waters and the incidence of radiation during this period, it was concluded that such low values of primary production in the Antarctic Ocean might be caused by the near freezing water temperatures and the deep mixed layer in that area. SASAK[ T., K. OZAWA and I. OKLmO, 1963. 14. On the chemical elements of sea water in the Kuril Trench taken by the bathyscaphe " A r c h i m ~ d e " (Etude chimique de l'eau relev~ de la fosse des Kouriles par le bathyscaphe franeais "Archim/~de ") (In Japanese, French r6sum6). Bull. Hakodate Mar. Obs., (10): 3-6, Reprint from: La Met, 1963, l (l): 3-6. On montre le r6sultat de l'analyse chimique des eaux que le bathyscaphe Archimede a relev6es en diverses profondeurs lors sa p l o n g ~ jusqu'~t 9545 m pros de l'Archipel du Japon, en compara.ison
Oceanographic Abstracts
RUSNAK GENE A., ROBERT L. FISHER and FRANCIS P. SHEPARD, 1964. Bathymetry and faults of G u l f o f California. In: Marine geology of the Gulf of California, a symposium, Amer. Ass. Petrol. Geol., Memoir. (Edited by VAN ANDEL T. and GEORGE G. SHOR JR.), 3: 59-75, The numerous cruises of Scripps Institution vessels to the Gulf of CaLifornia between 1957 and 1963 have provided thousands of miles of new sounding lines that have made possible an extensive revision of the earlier bathymetric charts. The fault scarps suggested by earlier soundings are now well confirmed, and also th~ indications of right-lateral movement with resulting tensional fractures. Several newly discovered northeast-trending deeps have been discovered. En echelon faults diagonal to the general trend of the Gulf are apparently a southward extension of the San Andreas system. Displacements of the order of 160 miles appear to have taken place between the two sides of the G u l l with a break in the crust forming the central G u l f with its near-oceanic depths. The end of the Baja California Peninsula is thought to have been located originally in the vicinity of Banderas Bay on the mainland. Two types of elevations occur in the Gulf : Those forming islands and banks along the western margin and consisting largely o f ' granite,' and central highs, most of which do not reach the surface and contain basic volcanics. The continental shelves are very narrow or nonexistent on the west side of the Gulf but fairly broad on the east, especially to the south of Mazatlfin. The eastern shelves appear to be of a depositional character. RUSSELL R. C. H. and J. R. C. DYKE, 1963. The direction of net sediment transport caused by waves passing over a horizontal bed. Int. Ass. Hydraul. Res., Congr., Lurid., 1963: 41-46. Results are presented of experiments to determine when the net transport of sediment comprising the horizontal bed of a laboratory channel is towards, and when away from, the beach. The direction of the net transport and its discharge rate were determined by observations on the movement of fluorescent tracers. It was found that when the bed was rippled, short waves produced transport towards the beach, and long waves transport away from the beach, the tendency to transport away from the beach being greater as the depth of water was reduced. Transport on a bed that was not rippled was invariably towards the beach. It is shown theoretically that it is not possible to make a wave model, with water as the fluid, in which the net transport is correctly reproduced. Every combination of conditions needs to be studied separately. RUSSELL R. C. H., n . E. NEWMAN and K. W. TOMLINSON, 1963. Sediment discharges measured by continuous injection of tracers from a point. Int. Ass. Hydraul Res., Congr., Lond., 1963: 69-76. A method is presented for obtaining the intensity of a sediment discharge by continuous injection of tracer sediment at a point near the bed, followed by sampling for surface concentration on a line across the flow. Experiments are described that were carried out in a wave-basin to determine the accuracy of the method and also to determine how close to the injection point the sampling could be done. A method is suggested for the way in which this minimum distance--3 ft under the particular conditions used~should be scaled up to obtain the prototype figure. SACHS P. L., 1964. A hydraulically actuated safety device, d. Mar. Res., 22 (1): 105-109. A hydraulically-actuated safety device has been built and has proved effective in reducing accidental, premature op~ration of oceanographic samplers. It consists of a cylinder, a piston, and a shear actuated by the piston. Increasing hydrostatic pressure acting on one side of the piston shears a pin at a predetermined depth, thus arming instruments sensitive to sudden motion. SAIJO Y. and T. KAWASHLMA, 1964. Primary production in the Antarctic Ocean. J. Oceanogr. Soc., Japan, 19 (4): 190-196. Studies on primary production were made in the Antarctic Ocean, between 40°W and 100°E, from December 1961 to February 1962. At ten stations, chlorophyll-a and photosynthetic rates were determined for surface samples, as well as the depth of Secchi disk reading. At thirty-five other stations only the chlorophyll-a in surface water was determined. At most of the stations the chlorophyll-a contents were very low (i.e. 0.02 to 0.22 mg/m a) except at a few stations where higher values (i.e. 0-3-0.6 g/m s) were obtained. The photosynthetic rates determined by the 14C technique under optimumlight conditions ranged from 0-06 to 0"80 mg C/m3/hr, and the mean value of photosynthesis per unit amount of chlorophyll was 1.22 mg C/mg chl./hr. The daily primary production beneath a unit surface, calculated from the above results and light data ranged from 0-01 to 0'15 g C/m2/day. After consideration o f t b e high concentration of nutrients in the sample waters and the incidence of radiation during this period, it was concluded that such low values of primary production in the Antarctic Ocean might be caused by the near freezing water temperatures and the deep mixed layer in that area. SASAK[ T., K. OZAWA and I. OKLmO, 1963. 14. On the chemical elements of sea water in the Kuril Trench taken by the bathyscaphe " A r c h i m ~ d e " (Etude chimique de l'eau relev~ de la fosse des Kouriles par le bathyscaphe franeais "Archim/~de ") (In Japanese, French r6sum6). Bull. Hakodate Mar. Obs., (10): 3-6, Reprint from: La Met, 1963, l (l): 3-6. On montre le r6sultat de l'analyse chimique des eaux que le bathyscaphe Archimede a relev6es en diverses profondeurs lors sa p l o n g ~ jusqu'~t 9545 m pros de l'Archipel du Japon, en compara.ison