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31.
V. M. Kushnir 《Oceanology》2007,47(1):33-41
Measurements of 14 vertical profiles of currents and hydrological parameters in the near-bottom layer with a depth resolution of 0.1 m were carried out in several regions of the Black Sea shelf, at five points over the continental slope, and in three deep water regions. The upper boundary of the benthic boundary layer (BBL) was reliably determined at a point at a distance from 5–7 to 35–40 m from the bottom where the gradients of the density and the velocity of the currents changed. The experimental data obtained were used to determine the coefficient of the bottom friction, the friction velocity, the coefficients of the vertical diffusion of momentum and density, and the vertical fluxes of temperature and salinity in the BBL. 相似文献
32.
We present a method for the determination of the trajectory of a sounding instrument and its drift velocity in the field of
currents nonuniform in depth and develop special software for IBM/PC compatible computers. The proposed method and software
are checked by using the well-known analytic solution of a similar problem given by Academician A. N. Krylov. We also consider
some special examples of application of the developed method to the processing of the data of an OLT profilometer.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
33.
Jacob Kushnir 《Geochimica et cosmochimica acta》1980,44(10):1471-1482
The coprecipitation of Sr2+, Mg2+, Na+, K+ and Cl? into gypsum was studied as a function of temperature, brine concentration and growth rate. The concentrations of the studied cations in the gypsum increase with growth rate (kinetic effect), with a tendency to reach a limiting value at high growth rates. The partition coefficients of Sr tend to increase with brine concentration and decrease with temperature. The partition coefficients of the other cations also decrease with temperature but depend only very slightly on brine concentration. The concentrations of coprecipitated chloride are negligibly small.The coprecipitation behavior is explained in terms of the relation between the rate of desorption of the coprecipitating ions from the surface of the growing crystal, and the rate of growth. The studied cations may substitute for Ca2+ in its normal lattice sites and/or reside in interstitial positions among the structural water molecules. The relative amount of foreign cations occupying interstitial positions increases with increasing growth rate.The elucidation of the behavior of coprecipitated ions in gypsum given here forms a basis for the utilization of these ions as geochemical indicators for the environment of deposition of gypsum. These indicators may help in reconstructing important parameters such as temperature, brine concentration and growth rate. 相似文献
34.
I. Ya. Chebotareva A. F. Kushnir M. V. Rozhkov 《Izvestiya Physics of the Solid Earth》2008,44(12):1002-1017
Emission tomography used in passive seismic monitoring of hydrocarbon deposits enables regular inspection of development of hydraulic fracturing and relaxation processes in volumes of fracturing, tracing of fluid migration paths, redistribution of stresses due to field development accompanied by seismic emission from volumes of structural defects and stress concentration, and localization of fractured and faulted structures from emission and scattering data. Intensive man-made seismic noise in the areas of oil field development produces a strong screening effect in identification of weak deep seismic sources. On the basis of experiments with simulated and real data of surface seismic arrays in regions of oil deposits in Western Siberia (carried out in the framework of the passive monitoring program of the SYNAPSE Science Center), it is shown that the use of algorithms of adaptive optimal and rejection spatial filtering with the estimation of the spectral density matrix of multichannel observations in the framework of multivariate autoregressive-moving average modeling is effective for eliminating the influence of anthropogenic noise and revealing (in oil production areas) both deep seismic sources supposedly active in scattering regions of the lower part of the sedimentary cover and the crystalline basement. The projection of the scattering regions onto the horizontal plane correlates well with the position of faults in the area of in situ observations. 相似文献
35.
A. F. Kushnir A. V. Varypaev M. V. Rozhkov A. G. Epiphansky I. Dricker 《Izvestiya Physics of the Solid Earth》2014,50(3):334-354
The world experience shows that hydraulic fracturing (fracking) is an efficient tool for increasing oil and gas production of low-permeable reservoirs in hydrocarbon fields. The fracking-induced fractures in the rock, which are hydrodynamically connected with the wells, significantly enhance the volumes of extracted hydrocarbons. Controlling the processes of fracture formation and propagation is a vital question in the oil and gas reservoir management. A key means to implement this control is provided by microseismic monitoring of fracking, which makes it possible to promptly reconstruct the geometry of the fractures from the data on seismic waves from the microearthquakes induced by the formation and propagation of fractures. 相似文献
36.
The main relationships for the design of the equilibrium of the sub-surface mooring (SM) are given based on the general equations describing the equilibrium of the elastic heavy cable under gravity and hydrodynamic loading. A computation system for the numerical modelling of SM under the effect of steady currents has been developed. Computations have been performed for conditions close to those in the main Black Sea current. The main parameters of the SM equilibrium under variation of the steady velocity profiles were estimated.Translated by Mikhail M. Trufanov. 相似文献
37.
Jacob Kushnir 《Geochimica et cosmochimica acta》1982,46(3):433-446
The coprecipitation of Sr, Mg, Na and K with anhydrite during the dehydration of gypsum was studied in laboratory experiments. The partition coefficients of Mg and Sr between anhydrite and solution decrease with increasing temperature. The partition coefficients of the alkali-ions do not depend upon temperature, but are affected by the brine composition.The mechanism of the phase transformation gypsum → anhydrite occurs via dissolution and precipitation, when the coprecipitated-ions are repartitioned between the new phase and the solution. The partition coefficients established in this study are applicable also for primary anhydrite.During the dehydration of gypsum at elevated temperatures metastable bassanite may form as an intermediate stage. The amount of cations coprecipitated with bassanite is much larger than the amount coprecipitated with anhydrite or gypsum. This phenomenon may have an influence on the partitioning of cations during the dehydration of gypsum, particularly on Sr.The partition coefficients of seawater cations between anhydrite and the brine are similar to those between gypsum and the brine. For this reason the coprecipitated-ions are not expected to be good indicators to distinguish between primary and secondary calcium sulfate minerals.The temperature effect on the coprecipitation of Mg and Sr with anhydrite makes these ions possible indicators for the temperature at which the phase transformation occurred. This temperature corresponds to the depth of burial of the gypsum at the stage of dehydration.The coprecipitation of seawater cations with anhydrite in the natural environment was studied in two systems: A small Pleistocene evaporite lens from the Sinai Peninsula and the Triassic anhydrite of the Mohilla Formation, Israel. The coprecipitated-ion composition of these samples was used to derive the conditions under which the anhydrite was formed. 相似文献