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Petrishchevsky A. M. Izosov L. A. Emelyanova T. A. Vasileva M. A. Lee N. S. 《Oceanology》2021,61(1):104-118
Oceanology - The geological-structural, magmatic, seismic, and thermometric models of the Earth’s crust and upper mantle of the Sea of Japan region are considered in relation to... 相似文献
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The elements Al, Cd, Co, Cu, Ni and Zn were concentrated from seawater using tetraethylenepentamine resin and analysed by atomic absorption spectrophotometry. The spatial distribution of these elements in the northwest Atlantic Ocean is discussed with respect to possible riverine inputs to the area from Puerto Rico. 相似文献
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This paper discusses remote sensing (RS) of the major types of water bodies by means of microwave radiometry. The analysis is based on theoretical models and experimental data taken under laboratory conditions, in a pool, from a shore, and over the oceans using aircraft and satellites. The radiation is found to depend on wind speed and the geometry of ripples, gravity waves, swell, foam, and some physical and chemical parameters of water such as its temperature, salinity, and concentration of some types of polutants. The estimates of the effectiveness of the microwave radiometric method for determining the above mentioned water-surface parameters are given. Examples of the application of microwave radiometry to obtaining operational information about some of them are also presented. The types of water observed are the inland waters, fresh or with a high concentration of salts, clean or polluted, and the oceans. The paper is based on the theoretical and experimental investigations conducted by the author and his colleagues at the Institute of Radio Engineering and Electronics of the Academy of Sciences in the USSR over the last 20 years. It also draws upon well-known Soviet and foreign publications. 相似文献
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J. David Smith Lorraine Plues Mireille Heyraud Robin D. Cherry 《Marine environmental research》1984,13(1):55-68
Ag, Al, Ca, Cd, Cu, Fe, Mg, Mn, Pb and Zn concentrations and 210Po and 210Pb activities were measured in 26 specimens of the squid Nototodarus gouldi taken from the waters of Bass Strait in one jigging operation. All the elements show wide ranges in concentrations in specimens apparently subject to the same environmental conditions. Copper concentration was 27-1 200 μg/g, and 210Po activity 4·8–24·2 Bq/g. The animal wet weights, the elements Ag, Al, Cd, Fe and Zn, and the radionuclide 210Po have coefficients of variation in the range 40–60%; Ca, Mg and Mn show the smallest variability (CV = < 30%), and Cu the greatest (CV = 12%). Significant correlations (p < 0·001) were found between the following pairs of elements: Cd-Zn, Cd-Cu, Zn-Cu, Mg-Mn, Fe-Mn, Ca-Mg and Fe-210Po. 相似文献
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Soil-sized particulates have been collected on board ship by a mesh technique from the lower troposphere of the North, Equatorial and South Atlantic Ocean, northern and southern Indian Ocean, South and East China Sea and various coastal localities.Spectrographic analysis reveals that, on average, the particulates have concentrations of Mn, Ni, Co, Ga, Cr, V, Ba, and Sr which are of the same order of magnitude as those in average crustal material. In contrast, the average concentrations of Pb, Sn, and Zn are one order of magnitude higher than those in average crustal material.Within this “world-wide” average there are significant geographical variations in the distributions of Pb, Sn, and Zn which may be related to anthropogenic sources.On the basis of trace-element distributions lower tropospheric soil-sized marine particulates have been divided into four genetic components; local, zonal, inter-zonal, and global. The proportions of these components vary geographically, and each component may have both a natural and an anthropogenic fraction. 相似文献
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The current methods used in world practice for the determination of the basic parameters of the vital functions of bacterioplankton
(the number, biomass, and production) are discussed. While comparing the different methods and their modifications, the peculiarities
of their application for particular natural or laboratory environments are emphasized. The specificity of applying different
microbiological methods for field research is examined. When choosing the methodological base for describing the characteristics
of a bacterial community, one should proceed from the specific problem facing the researcher. In the case of routine monitoring,
the following techniques are convenient and widely used: direct counts of DAPI fluorochrome-stained bacteria using a fluorescence
microscope; the calculation of the biomass of the microorganisms on the basis of the relationship between the cell’s mass
and its size; the estimation of the bacteria production via labeled leucine incorporation. 相似文献
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D. G. Masson 《Marine Geophysical Researches》1984,6(4):365-382
The northern Mascarene Basin, lying between Madagascar and the Seychelles Plateau in the north-west Indian Ocean, is marked at its north-western end by the Amirante Arc, an enigmatic ridge-trench complex superficially resembling an island arc. Structural trends in the area have been mapped using GLORIA sidescan sonar data, seismic reflection profiles and bathymetric maps. It is concluded that the north-west Mascarene Basin was created during the Late Cretaceous by sea-floor spreading about a north-west trending spreading axis cut by northeast trending transform faults. A major transform fault between the northern tip of Madagascar and the western margin of the Seychelles Plateau is proposed as a boundary between the Late Cretaceous Mascarene basin and the older Somali Basin to the north-west. The northern segment of the Amirante Ridge may mark part of the transform. The southern segment of the Ridge and its associated trench are, however, wholly contained within the Late Cretaceous ocean floor of the Mascarene Basin, and are best explained as compressional features related to a change in sea-floor spreading geometry in the Late Cretaceous or earliest Tertiary. Two models for the evolution of the Mascarene Basin are proposed, the major differences between them being the amount of subduction at the southern Amirante Arc and the timing of the initial separation between India and the Seychelles. 相似文献
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20 0 0年 10月～ 2 0 0 1年 12月 ,对青岛太平角养殖海区的贻贝寄生中华豆蟹的感染情况进行了调查。以肥满指数为指标 ,通过对感染和未感染贻贝的比较 ,分析了中华豆蟹对贻贝的危害程度。结果表明 ,中华豆蟹对贻贝的感染率为 2 .0 %～ 2 0 .4 %。2 0 0 0年 11月和 2 0 0 1年 11月出现 2次感染高峰 ,分别为 9.7%和 2 0 .4 % ;最低感染率出现于 2 0 0 1年 1月和 3月 (均为 2 .0 % )。感染强度为 1～ 5 ,多数为 1(占感染个体的 83.2 % )。贻贝所感染的豆蟹的性别及感染强度与宿主的大小有关。小个体贻贝仅见雄豆蟹感染 ,绝大多数雌豆蟹见于壳长大于 2 cm的贻贝。未发现同一宿主体内同时感染 2只或以上的雌豆蟹。在调查的 15个月中 ,有 11个月被感染贻贝的肥满度显著低于未感染的贻贝 ,且雌豆蟹对宿主肥满度的影响大于雄豆蟹 相似文献
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The Mediterranean margin of Libya can be divided into three physiographic provinces, the Pelagian Shelf, the Sirt Embayment, and Offshore Cyrenaica. The petroleum potential of the Pelagian Shelf has been investigated but the Sirt Embayment and Offshore Cyrenaica are almost unexplored. During 2004–2005, new 2D pre-stack time-migrated seismic data were acquired and used to examine the large-scale structural, depositional, and salt tectonic features of the Libyan shelf and slope. The data cover approximately 38,000 line kilometers in water depths ranging from under 50 to over 3000 m.Cenozoic strata along much of the Libyan margin have a demonstrable progradational character punctuated by surfaces of erosion and margin failure. Within the Sirt Embayment the most visible retrogradational surface becomes seismically coincident with the top of Messinian unconformity. This retrogradational surface extends for over 700 km along strike and cuts both sides of the Sirt Embayment. Over 5000 cubic kilometers of material are missing from above this surface. There are two ideas for how retrogradation occurred. One idea relates the retrogradation to margin erosion during the Messinian salinity crisis. The other idea suggests that a large part of the Libyan margin experienced a cataclysmic failure during the late Miocene.Some existing models for offshore Libya have interpreted a widespread layer of halite lying within the Messinian which thickens basinward. This interpretation was probably based on the fact seismic reflection continuity was lost over much of the Sirt Embayment on older data beneath the top Messinian unconformity. The loss of good reflection character adversely affected exploration efforts by obscuring deep structures. Recent seismic data and a current understanding of salt behavior do not support the interpretation of thick halite within the Messinian section. Regional observations do not indicate any mobile halite present in the Sirt Embayment. There is a relatively thin, high amplitude and high velocity layer of non-halite evaporites (mainly anhydrite) which caps the Messinian section. Where this high amplitude and high velocity layer is absent or eroded, seismic continuity within the Messinian interval is restored. Limited available well data support this interpretation.True mobile halite is interpreted to exist in offshore Libya only in the far west of the Pelagian Shelf near the Tunisian border. Beneath the Pelagian Shelf are a series of tight contractional folds that are interpreted to be salt cored. Basins adjacent to the folds display geometries characteristic of salt withdrawal. The fold crests formed bathymetric highs which served as nucleation sites for nummulitic shoal development. These shoals are the principal reservoirs of the Pelagian Shelf. 相似文献
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Abstract
Oncaea venusta Philippi, 1843 has been known as having some different size groups, but recent genetic study for cyt b and ITS 1 (Elverset al. 2006) suggests that these size groups can be considered as different species. Of these size groups, the largestO. venusta Philippi and the smallestO. venella Farran, 1929 were first described in Korean waters. The latter is easily distinguishable from the former in the following
characteristics in addition to its small size: (1) length to width ratio of genital double somite of two genders smaller,
and (2) female second pediger bearing inconspicuous dorso-posterior swelling.Oncaea venusta andO. venella co-occur in Korean waters during spring to fall, but their occurrence patterns seasonally differ: the former shows higher
density in fall while the latter does in summer. 相似文献
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Reliable methods have been developed for the quantitative estimation of chitin, chitosan and chitin deacetylase in sediment samples, as well as two methods for the estimation of chitinase in these samples. The differing substrates used in the latter two methods have produced distinct ‘depth profiles’ for chitinase activity which suggest the presence of more than one chitinolytic system in the sediments of the Ythan estuary. Studies on the mineralization of chitin in these sediments have revealed a complex system with a number of unexpected features. The rate of chitin degradation was reduced in late summer, possibly due to the heavy seaweed growth which covers the mud flats at this time, although the potential degradative activities of the enzymes chitinase and chitin deacetylase were higher in summer than in winter. The proportional rates of degradation of chitin, chitosan and cellulose were similar in both the absence and presence of seaweed overgrowth, although the apparent rates of degradation of these substrates were higher in the absence of seaweeds. Core samples have indicated that the major input of chitin to the sediment ecosystem occurs via deposition at the surface, while the input of chitosan (the deacetylated polymer) occurs via its production within the sediment, primarily within the upper 5 cm of sediment. The concentrations of both these polymers decreased sharply below an ‘interface’ between aerobic and anoxic sediments. 相似文献
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Cross-Calibration and Long-Term Monitoring of the Microwave Radiometers of ERS,TOPEX, GFO,Jason, and Envisat 总被引：1，自引：1，他引：0
The radiometers on board the satellites ERS-1, TOPEX/Poseidon, ERS-2, GFO, Jason-1, and Envisat measure brightness temperatures at two or three different frequencies to determine the total columnal water vapor content and wet tropospheric path delay, a major correction to the altimeter range measurements. In order to asses the long-term stability of the path delay, the radiometers are calibrated against vicarious cold and hot references, against each other, and against several atmospheric models. Four of these radiometers exhibit significant drifts in at least one of the channels, resulting in yet unmodeled errors in path delay of up to 1 mm/year, thus limiting the accuracy at which global sea level rise can be inferred from the altimeter range measurements. 相似文献
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The radiometers on board the satellites ERS-1, TOPEX/Poseidon, ERS-2, GFO, Jason-1, and Envisat measure brightness temperatures at two or three different frequencies to determine the total columnal water vapor content and wet tropospheric path delay, a major correction to the altimeter range measurements. In order to asses the long-term stability of the path delay, the radiometers are calibrated against vicarious cold and hot references, against each other, and against several atmospheric models. Four of these radiometers exhibit significant drifts in at least one of the channels, resulting in yet unmodeled errors in path delay of up to 1 mm/year, thus limiting the accuracy at which global sea level rise can be inferred from the altimeter range measurements. 相似文献
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Abstract. The production of the hymenosomatid crab Elamenopsis kempi was calculated for a period of 18 months from a subtidal area of the Garmat-Ali river, southern Iraq. The highest average individual somatic energy was attained in spring. Maximum population biomass and production were attained by the summer cohort and the minimum values were exhibited by the overwintering cohort. The fluctuations of the average population biomass were followed throughout the sampling period. Average total annual population production was 13.2 g DW · m-2 · a-1 and the P/B ratio was 5.9. These values were compared with those of the most common crustaceans in the region. 相似文献
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