共查询到20条相似文献，搜索用时 62 毫秒
1.
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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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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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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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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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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Izvestiya, Atmospheric and Oceanic Physics - In order to develop astromineralogy, an emerging new research area, the results of studying the features of mineral genesis and geochemistry of native... 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
10.
H.A. van der Sloot D. Hoede J. Wijkstra J.C. Duinker R.F. Nolting 《Estuarine, Coastal and Shelf Science》1985,21(5):633-651
Oxy-anionic species of V, As, Se, Mo, Sb, Te and W were measured in solution and suspension in samples obtained during several cruises in the Dutch Wadden Sea, the offshore region of the Southern Bight (North Sea) and in the estuaries of the Rhine and Scheldt. Dissolved concentrations at salinities above 34·5 × 10?3 ( = 34·5%. S) agreed generally well with published open ocean values. It is suggested that Se speciation differs from the open ocean.In the Wadden Sea, concentrations of V, Se, Mo and Sb were linearly related to salinity (10–35 × 10?3). The good agreement between measured and extrapolated values at a salinity of 0·5 × 10?3 suggests conservative behaviour in the Rhine estuary (with residence time of freshwater in the order of a few days).Dissolved concentration vs. salinity plots in the Scheldt estuary (residence time 2–3 months) showed pronounced minima and maxima. These occurred in the low or medium salinity range for V, As and Sb. Linear behaviour was observed for Se and Mo (in some cases, relatively large differences between cruises were detected). Deviations from linearity in the plots are interpreted in terms of thermodynamic equilibrium conditions involving species with different solubilities (V), local input from land (As, Se, Sb, Te) and removal from solution (As), probably through coprecipitation with Fe(OH)3.In the offshore samples, the contributions of particulate forms to the total element concentrations were small (<15%). At higher SPM concentrations (about 30 mg dm?3), this percentage remained small for Se, Mo and Sb (<15%); it was substantial for V and As (25–50%). 相似文献
11.
《Marine Policy》2017
In recent years, clusters of industry have attracted multilateral attention, from academia and practice, alike. Clusters of industry relate to harbouring regional competitiveness; as such, they have come to be considered as important constructs for strategy and policy, that can be deemed as complementary domains. At the same time, maritime clusters are regarded as dynamic cases from a multitude of viewpoints. The concepts of strategic policy, particularly as they pertain to maritime clusters, require deeper understanding and more thorough analysis. In this context, cluster typologies surface as a useful instrument that can offer valuable insight. While this field instils the eventuality of facilitating policy and strategy within clusters, it remains relatively barren. This instance may present the opportunity to better elaborate on the formulation of models and frameworks that address the intricacies within maritime clusters. The research conducted introduces a three-tier framework for the generation of maritime cluster typologies, that bears the potential to enrich strategic management and its eventual policy implications, towards a more streamlined and informed manifestation. 相似文献
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Economics, fisheries, and the marine environment 总被引：1，自引：2，他引：1
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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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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
18.
The Magdalena Fan can be divided into: upper fan—1:60–1:110 gradients, channels with well-developed levees, generally several
subbottom reflectors on 3.5-kHz records, and fine-grained sediments; middle fan—1:110–1:200 gradients, channels with very
subdued levees, several to few subbottom reflectors on 3.5-kHz records, and chaotic and discontinuous reflections on multichannel
seismic (MCS) records; lower fan—<1:250 gradients, small channels and relatively smooth seafloor, generally coarsegrained
sediments, few or no subbottom reflectors on 3.5-kHz records, and flat continuous reflections on MCS records. In addition
to the turbidity currents, slumping along the continental slope and elsewhere also influenced sedimentation in the fan.
Margin setting represents fan and/or source area 相似文献
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The Magdalena Fan can be divided into: upper fan—1:60–1:110 gradients, channels with well-developed levees, generally several subbottom reflectors on 3.5-kHz records, and fine-grained sediments; middle fan—1:110–1:200 gradients, channels with very subdued levees, several to few subbottom reflectors on 3.5-kHz records, and chaotic and discontinuous reflections on multichannel seismic (MCS) records; lower fan—<1:250 gradients, small channels and relatively smooth seafloor, generally coarsegrained sediments, few or no subbottom reflectors on 3.5-kHz records, and flat continuous reflections on MCS records. In addition to the turbidity currents, slumping along the continental slope and elsewhere also influenced sedimentation in the fan. 相似文献