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A preliminary account of wave observations in South African waters
660
Oceanographic Abstracts
Isolated sea mounts are relatively ineffective in converting tidal energy from the surface mode into internal modes. For a sea mount of optimum size the ' conversion w i d t h ' is of the order 1 per cent of the radius of the seamount. The conversion of tidal energy by the irregular bottom of the whole Atlantic Ocean is roughly estimated to provide internal waves with between 9 and 69 per cent of the power of the surface tide. Much of the energy will be transformed into very high modes. CI~AGEIt J. S., D. A. McMANUS and E. E. COLLINS,1962. Electronic data processing in sedimentary size analyses. J. Sediment. Petrol., 32 (4): 833-839. The use of electronic computers must become a standard technique in the processing of data from sedimentary analysis. The efficiency of electronic data computing increases the number of samples that can be processed, permits the use of a wider variety of statistics, eliminates much of the operator error, and frees the geologist for interpretive work. The system is adaptable to an expanded statistical analysis. The total expense of using the electronic computer is less than that of the hand method, when a large number of samples are run. A programme for use with the IBM 650 magnetic-drum processing system has been written which computes phi values of several percentiles, sand-silt-clay relationships, Trask values, Inman values, and Folk and Ward values. The results from this programme are compatible with those obtained using conventional hand methods. CURL H. Jr., 1962. Analyses of carbon in marine plankton organisms. J. Mar. Res., 20 (3): 181-188. Total carbon in nineteen species of marine organisms and mixed collections was analyzed by combustion in an induction furnace and by subsequent measurement of evolved carbon dioxide in a gas burette. A system for trapping unwanted combustion products is described. Carbonate carbon was analyzed by treating samples with acid and measuring evolved carbon dioxide. Carbon concentrations were 6.6-46.8 per cent of dry weight and 20.6-57.0 per cent of organic weight. Cnidaria and ctenophores had the lowest carbon concentrations in organic matter. DAMON M. H., 1963. Recording the sonar environment. Undersea Technol., 4 (1): 32-35. Several systems have been developed to record the complete omnidirectional acoustic history of the sonar environment under operational conditions. One system records omnidirectional information by recording narrow band signal data from preformed beams. Another system is a stave recorder, recording wide-band acoustic information directly from a multitude of hydrophones and serving as a ' virtual' transducer in the playback mode. Various multiplexing techniques are analyzed to establish the most efficient means of storing multi-channel analog signal data on magnetic tape, and the advantages and disadvantages of several modulation and multiplexing techniques are presented. DAS~YSHI~ M., 1962. A preliminary account of wave observations in South African waters.
S. Afric. J. Sci., 58 (12): 353-361. From preliminary work it appears that the seas adjacent to the coast of South Africa are a particularly interesting area for wave study, due to the prevalence of swell generated by the westerly winds in the sub-Antarctic region and by tropical storms in the Indian Ocean. From the examples given here it appears that the prediction method works well on most occasions. Its accuracy is, of course, limited by the accuracy of the weather charts and these in turn suffer from a paucity of information over a wide expanse of ocean. The collection and analysis of a large amount of wave data will provide a check for the prediction method and give the wave conditions to be expected in different areas at different times of year. DIETZ R. S., 1963. A theory of ocean basin origin. Undersea Technol., 4 (1): 26-29. Theories regarding the origin of ocean basins have been a matter of speculation for some time, although it is generally accepted that the formations are entirely related to geologic processes. Lately, however, evidence has pointed out that the earth's mantle apparently undergoes thermal convection which drastically affects the earth's surface and, in fact, seems to genetically account for and control the shape of the ocean basins. The author erttertains, with considerable merit, the idea of ocean basin formation by sea floor spreading. D u s o v V. P., 1958 (Transl. 1962). Model studies of Aral Sea seiches. Mosk. Inst. Inzh. Vod. Khozy. Nauch. Zap., 20: 321-329. Trans. listed in: Tech. Transl., 9 (l): 38. OTS or SLA 62-15474. The status of the Aral Sea seiche problem is considered. A model method for studying seiches is described and its advantages over field observations shown. Seiches are investigated on a specially equipped model of the Aral Sea. Unibi-, and trinodal longitudinal and a uninodal transversal seiche are detected; translating their periods into actual dimensions, their periods are equal to 21 hours 30 minutes, I0 hr 27 min, 6 hr 46 min, and 9 hr 10 min, respectively. The distribution of nodal lines and antinodes are vertical displacements is depicted. All seiches are well defined at the Aral Sea station. A beat phenomenon as the result of the overlapping of the binodal longitudinal and uninodal transversal seiches is detected. It is shown that it is necessary to use great caution in averaging the periods of seiches recorded by the tide gages, since a seiche, assumed to be a pure one, can
Oceanographic Abstracts
Isolated sea mounts are relatively ineffective in converting tidal energy from the surface mode into internal modes. For a sea mount of optimum size the ' conversion w i d t h ' is of the order 1 per cent of the radius of the seamount. The conversion of tidal energy by the irregular bottom of the whole Atlantic Ocean is roughly estimated to provide internal waves with between 9 and 69 per cent of the power of the surface tide. Much of the energy will be transformed into very high modes. CI~AGEIt J. S., D. A. McMANUS and E. E. COLLINS,1962. Electronic data processing in sedimentary size analyses. J. Sediment. Petrol., 32 (4): 833-839. The use of electronic computers must become a standard technique in the processing of data from sedimentary analysis. The efficiency of electronic data computing increases the number of samples that can be processed, permits the use of a wider variety of statistics, eliminates much of the operator error, and frees the geologist for interpretive work. The system is adaptable to an expanded statistical analysis. The total expense of using the electronic computer is less than that of the hand method, when a large number of samples are run. A programme for use with the IBM 650 magnetic-drum processing system has been written which computes phi values of several percentiles, sand-silt-clay relationships, Trask values, Inman values, and Folk and Ward values. The results from this programme are compatible with those obtained using conventional hand methods. CURL H. Jr., 1962. Analyses of carbon in marine plankton organisms. J. Mar. Res., 20 (3): 181-188. Total carbon in nineteen species of marine organisms and mixed collections was analyzed by combustion in an induction furnace and by subsequent measurement of evolved carbon dioxide in a gas burette. A system for trapping unwanted combustion products is described. Carbonate carbon was analyzed by treating samples with acid and measuring evolved carbon dioxide. Carbon concentrations were 6.6-46.8 per cent of dry weight and 20.6-57.0 per cent of organic weight. Cnidaria and ctenophores had the lowest carbon concentrations in organic matter. DAMON M. H., 1963. Recording the sonar environment. Undersea Technol., 4 (1): 32-35. Several systems have been developed to record the complete omnidirectional acoustic history of the sonar environment under operational conditions. One system records omnidirectional information by recording narrow band signal data from preformed beams. Another system is a stave recorder, recording wide-band acoustic information directly from a multitude of hydrophones and serving as a ' virtual' transducer in the playback mode. Various multiplexing techniques are analyzed to establish the most efficient means of storing multi-channel analog signal data on magnetic tape, and the advantages and disadvantages of several modulation and multiplexing techniques are presented. DAS~YSHI~ M., 1962. A preliminary account of wave observations in South African waters.
S. Afric. J. Sci., 58 (12): 353-361. From preliminary work it appears that the seas adjacent to the coast of South Africa are a particularly interesting area for wave study, due to the prevalence of swell generated by the westerly winds in the sub-Antarctic region and by tropical storms in the Indian Ocean. From the examples given here it appears that the prediction method works well on most occasions. Its accuracy is, of course, limited by the accuracy of the weather charts and these in turn suffer from a paucity of information over a wide expanse of ocean. The collection and analysis of a large amount of wave data will provide a check for the prediction method and give the wave conditions to be expected in different areas at different times of year. DIETZ R. S., 1963. A theory of ocean basin origin. Undersea Technol., 4 (1): 26-29. Theories regarding the origin of ocean basins have been a matter of speculation for some time, although it is generally accepted that the formations are entirely related to geologic processes. Lately, however, evidence has pointed out that the earth's mantle apparently undergoes thermal convection which drastically affects the earth's surface and, in fact, seems to genetically account for and control the shape of the ocean basins. The author erttertains, with considerable merit, the idea of ocean basin formation by sea floor spreading. D u s o v V. P., 1958 (Transl. 1962). Model studies of Aral Sea seiches. Mosk. Inst. Inzh. Vod. Khozy. Nauch. Zap., 20: 321-329. Trans. listed in: Tech. Transl., 9 (l): 38. OTS or SLA 62-15474. The status of the Aral Sea seiche problem is considered. A model method for studying seiches is described and its advantages over field observations shown. Seiches are investigated on a specially equipped model of the Aral Sea. Unibi-, and trinodal longitudinal and a uninodal transversal seiche are detected; translating their periods into actual dimensions, their periods are equal to 21 hours 30 minutes, I0 hr 27 min, 6 hr 46 min, and 9 hr 10 min, respectively. The distribution of nodal lines and antinodes are vertical displacements is depicted. All seiches are well defined at the Aral Sea station. A beat phenomenon as the result of the overlapping of the binodal longitudinal and uninodal transversal seiches is detected. It is shown that it is necessary to use great caution in averaging the periods of seiches recorded by the tide gages, since a seiche, assumed to be a pure one, can