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Diapric structures in the eastern Mediterranean Herodotus basin
Oceanographic Abstracts
215
SINGH S. S. and KSHUDIRAM SAHA, 1976. Numerical experiments with a primitive equation barotropic model for the prediction of movement of monsoon depressions and tropical cyclones. J. appL Met., 15 (8): 805-810. A limited-area primitive equation barotropic model with wind as input has been integrated up to 72 h to predict the movement of a monsoon depression and a tropical cyclone in the Indian region. The forecast up to 48 h is satisfactory in both cases whereas that beyond this period appears to deteriorate rapidly. SMART P.L., B. L. FINLAYSON, W. D. RYLANDS and C. M. BALL, 1976. The relation of fluorescence to dissolved organic carbon in surface waters. Wat. Res., 10 (9): 805-811. A rapid method for the estimation of organic carbon in natural waters which could be adapted to continuous measurement is needed to improve water quality monitoring. The fluorescent properties of natural organic molecules offer such a method. The'fluorescence of natural waters from a variety of surface sources, using an excitation wavelength of 365 nm and emission wavelengths in the range 400-600 nm have been correlated with total organic carbon levels. The results are highly significant statistically and show that fluorescence can be used as a predictor of "FOC over a wide range of concentrations. SMITH L.R., C. B. MILLER and R. L. HOLTON, 1976. Small-scale horizontal distribution of coastal copepods. Z exp. mar. Biol. Ecol., 23 (3): 241-253. The horizontal spatial distribution of four species of coastal copepods was investigated by pumping two continuous series of samples and subjecting the data collected to statistical analysis. Sampling was conducted 1.5 km offshore of Moolack Beach, Oregon, at a depth of 7 m. Two small boats, each equipped with a pump of 280 1. min -1 capacity, were anchored 40 m apart and collected a series of 50 consecutive, paired zooplankton samples. Current speed and direction were measured at the beginning of each sampling interval. The amplitude and frequency of the fluctuations in copepod densities indicate large changes in density over linear distances of 30 m to a few hundreds of meters. Maxima of abundance occurred simultaneously for most categories of copepods counted. Time series analysis showed that there was a lag of 12 rain (equivalent to 159 m) between the occurrence of abundance maxima at the seaward and shoreward boats. This suggests that the variations in zooplankton density occurred in a pattern which is oblique to the direction of the current. SMITH S.G., 1976. Diapiric structures in the eastern Mediterranean Herodotus basin. Earth planet. ScL Letts, 32 (1): 62-68. A 45-km square seismic reflection profiling grid survey was made in the part of the Herodotus basin where there is a large thickness of strongly deformed sediment, to determine the nature and cause of the deformation. The survey showed that the area has sediment ponded between highs in the underlying deformed sedimentary sequence, which becomes more deformed with increasing depth. The deepest continuous reflector that can be seen is probably reflector M. The seismic velocity above this is 3.2 km s -~ ; a velocity could not be obtained from below this reflector. A map of depth to reflector M shows small rises superimposed on a strong linear north-south rise. There are no magnetic anomalies associated with any of these rises, so they are not caused by doming above igneous intrusions. The structures could be caused by syn-depositional folding, or sedimentary diapirism, of which sedimentary diapirism seems the most probable. SOURNIA A., 1976. Primary production of sands in the lagoon of an atoll and the role of foraminiferan symbionts. Mar, Biol., 37 (1): 29-32. Chlorophyll content and in situ oxygen production of sands were measured in the lagoon of Takapoto Atoll, Tuamotu Islands (French Polynesia). Stations were spaced from a depth of 17 m to the water limit on the beach. Photosynthetic pigments and net primary production for the top 3 cm of sediment ranged from 56 to 907 mg chlorophyll a m -2 and from 115 to 354 mg 02 m -2 h -~ , respectively. Responsible organisms were mostly Foramiriifera, among which Amphistegina lessoni, containing unicellular symbionts, dominated. The sands are thus significant contributors to the lagoon's primary production, while the role of phytoplankton is comparatively negligible. SPOHR MARGRET y J. CORRAL, 1976. Primeros datos sobre la sistem~itica y ecologia de los cop6podos de la rfa dc Muros (NW de Espana). Boln. Inst. esp. Oceanogr., 2 0 6 : 2 5 pp. Copepod samples taken in the Rfa de Muros (NW of Spain) in November 1975 show: (1) The number of species was 24. Dominant species were Temo'ra longicornis and Acartia clausi which contributed 78% and 63%. (2) The composition of the community and its diversity showed significant changes in only four days. (3) Values of copepods/cubic meter ranged from 36 to 169. The mouth of Ensenada de Muros had the highest concentrations. (4) An analysis of variance for estimating the effect of two factors "time" and "space" on abundance of each species was made. The values were not ever significant at the 95% level, but they do allow a grouping of species where there is (i) a higher influence of "space" than "time", (ii) a higher influence of "time" than "space", and (iii) a balance of the two factors. (5) The plotting of the species for both factors showed that T. longicornis and A. clausi are the most distant. (6) The change of slope of the straight lines of regression is explained by a growth in the structural complexity of the community because of the appearance of new species and a better balance of abundances among them.
215
SINGH S. S. and KSHUDIRAM SAHA, 1976. Numerical experiments with a primitive equation barotropic model for the prediction of movement of monsoon depressions and tropical cyclones. J. appL Met., 15 (8): 805-810. A limited-area primitive equation barotropic model with wind as input has been integrated up to 72 h to predict the movement of a monsoon depression and a tropical cyclone in the Indian region. The forecast up to 48 h is satisfactory in both cases whereas that beyond this period appears to deteriorate rapidly. SMART P.L., B. L. FINLAYSON, W. D. RYLANDS and C. M. BALL, 1976. The relation of fluorescence to dissolved organic carbon in surface waters. Wat. Res., 10 (9): 805-811. A rapid method for the estimation of organic carbon in natural waters which could be adapted to continuous measurement is needed to improve water quality monitoring. The fluorescent properties of natural organic molecules offer such a method. The'fluorescence of natural waters from a variety of surface sources, using an excitation wavelength of 365 nm and emission wavelengths in the range 400-600 nm have been correlated with total organic carbon levels. The results are highly significant statistically and show that fluorescence can be used as a predictor of "FOC over a wide range of concentrations. SMITH L.R., C. B. MILLER and R. L. HOLTON, 1976. Small-scale horizontal distribution of coastal copepods. Z exp. mar. Biol. Ecol., 23 (3): 241-253. The horizontal spatial distribution of four species of coastal copepods was investigated by pumping two continuous series of samples and subjecting the data collected to statistical analysis. Sampling was conducted 1.5 km offshore of Moolack Beach, Oregon, at a depth of 7 m. Two small boats, each equipped with a pump of 280 1. min -1 capacity, were anchored 40 m apart and collected a series of 50 consecutive, paired zooplankton samples. Current speed and direction were measured at the beginning of each sampling interval. The amplitude and frequency of the fluctuations in copepod densities indicate large changes in density over linear distances of 30 m to a few hundreds of meters. Maxima of abundance occurred simultaneously for most categories of copepods counted. Time series analysis showed that there was a lag of 12 rain (equivalent to 159 m) between the occurrence of abundance maxima at the seaward and shoreward boats. This suggests that the variations in zooplankton density occurred in a pattern which is oblique to the direction of the current. SMITH S.G., 1976. Diapiric structures in the eastern Mediterranean Herodotus basin. Earth planet. ScL Letts, 32 (1): 62-68. A 45-km square seismic reflection profiling grid survey was made in the part of the Herodotus basin where there is a large thickness of strongly deformed sediment, to determine the nature and cause of the deformation. The survey showed that the area has sediment ponded between highs in the underlying deformed sedimentary sequence, which becomes more deformed with increasing depth. The deepest continuous reflector that can be seen is probably reflector M. The seismic velocity above this is 3.2 km s -~ ; a velocity could not be obtained from below this reflector. A map of depth to reflector M shows small rises superimposed on a strong linear north-south rise. There are no magnetic anomalies associated with any of these rises, so they are not caused by doming above igneous intrusions. The structures could be caused by syn-depositional folding, or sedimentary diapirism, of which sedimentary diapirism seems the most probable. SOURNIA A., 1976. Primary production of sands in the lagoon of an atoll and the role of foraminiferan symbionts. Mar, Biol., 37 (1): 29-32. Chlorophyll content and in situ oxygen production of sands were measured in the lagoon of Takapoto Atoll, Tuamotu Islands (French Polynesia). Stations were spaced from a depth of 17 m to the water limit on the beach. Photosynthetic pigments and net primary production for the top 3 cm of sediment ranged from 56 to 907 mg chlorophyll a m -2 and from 115 to 354 mg 02 m -2 h -~ , respectively. Responsible organisms were mostly Foramiriifera, among which Amphistegina lessoni, containing unicellular symbionts, dominated. The sands are thus significant contributors to the lagoon's primary production, while the role of phytoplankton is comparatively negligible. SPOHR MARGRET y J. CORRAL, 1976. Primeros datos sobre la sistem~itica y ecologia de los cop6podos de la rfa dc Muros (NW de Espana). Boln. Inst. esp. Oceanogr., 2 0 6 : 2 5 pp. Copepod samples taken in the Rfa de Muros (NW of Spain) in November 1975 show: (1) The number of species was 24. Dominant species were Temo'ra longicornis and Acartia clausi which contributed 78% and 63%. (2) The composition of the community and its diversity showed significant changes in only four days. (3) Values of copepods/cubic meter ranged from 36 to 169. The mouth of Ensenada de Muros had the highest concentrations. (4) An analysis of variance for estimating the effect of two factors "time" and "space" on abundance of each species was made. The values were not ever significant at the 95% level, but they do allow a grouping of species where there is (i) a higher influence of "space" than "time", (ii) a higher influence of "time" than "space", and (iii) a balance of the two factors. (5) The plotting of the species for both factors showed that T. longicornis and A. clausi are the most distant. (6) The change of slope of the straight lines of regression is explained by a growth in the structural complexity of the community because of the appearance of new species and a better balance of abundances among them.