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41.
M. Mejías J. Garcia-Orellana J. L. Plata M. Marina E. Garcia-Solsona B. Ballesteros P. Masqué J. López C. Fernández-Arrojo 《Environmental Geology》2008,54(3):521-536
A methodology for the characterization of deep carbonate aquifers has been developed and applied to El Maestrazgo Jurassic
aquifer in Castellón, Spain. Characterization of these aquifer formations, located at more than 300 m deep, consisted of a
previous phase of compilation, analysis and synthesis of the existing information about the area, followed by a coordinated
combination of different speciality studies: geology, stratigraphy, structural analysis, hydrogeology, hydrochemistry, geophysics
and remote sensing. Geological studies included geological mapping, definition of stratigraphical units and facies and structural
analysis. The aim of the hydrogeology study was to define aquifer formations, recharge area, aquifer points inventory and
groundwater flow directions for the establishment of piezometric and water quality observation nets. Special techniques were
applied, like thermal infrared aerial images and the evaluation of submarine groundwater discharge by means of natural radium
isotopes. Hydrochemical techniques, including majority elements characterization and stable isotopes (18O, 2H and 3H) determination, allowed classifying hydrochemical facies and establishing a renewal pattern for water within the system.
Geophysics was useful in determining the aquifer geometry, the features of the basement and the petrophysical characteristics
of the geological formations. Preliminary results show an important tectonic complexity and the possibilities for groundwater
uses in the area of study. 相似文献
42.
43.
44.
Antonín Papež 《Studia Geophysica et Geodaetica》1964,8(2):200-204
Резюме Дабление воздуха, переснитанное иа уровень моря по стандартной атмосфере в Q-коде обозчачается через QNH. Давление воздуха
пересчитанное на уровень моря по высотной барометрической формуле обознаеается через QFF. Для целей авиационной службы погоды
должны быть известны значения QNH, однако Зе барическое поле на синоптических картах выражается через QFF. С помощью рис.
1 для соответствующей температуры воздуха на станцин и ее высоты н. у. м. можно определить разность значений QFF—QNH при давленин
QFF=1000мб. Далее по табл. 2 можно определить поправку для каждого значения QFF отличного от значения QFF при ином давлении, чем 1000мб путем умножения табулированного значения ва разность QFF—1000мб и его алгебраического сложения со значением, полученным по рис. 1.
相似文献
45.
46.
Резюме С помощью принятия простых кинематических предположений и на основании ω—уравнения выла определена конфигурация полос облаков
в полностью окклюдированном циклоне без фронтов. Облачная система определяется полем скрытой теплоты, выделяемой в процессах
конденсации. Полосы облаков теоретически представляют собой в основном листы синусоидальной спирали.
Address: Boční II, Praha 4-Spořilov. 相似文献
Address: Boční II, Praha 4-Spořilov. 相似文献
47.
48.
Jesús M. Mercado Teodoro Ramírez Dolores Corts Marta Sebastin Andreas Reul Begoa Bautista 《Estuarine, Coastal and Shelf Science》2006,69(3-4):459
The changes in the phytoplankton absorption properties during a diurnal cycle were investigated at one station located in the north-western area of the Alborán Sea. The experiment was performed in spring when the water column was strongly stratified. This hydrological situation permitted the establishment of a deep chlorophyll a (chl a) fluorescence maximum (DFM) which was located on average close to the lower limit of the mixed layer and the nutricline. The relative abundance of pico-phytoplankton (estimated as its contribution to the total chl a) was higher in the surface, however, micro-phytoplankton dominated the community at the DFM level. Chl a specific absorption coefficient (a*(λ)) also varied with optical depth, with a* (the spectrally average specific absorption coefficient) decreasing by 30% at the DFM depth with respect to the surface. A significant negative correlation between the contribution of the micro-phytoplankton to the total chl a and a* was obtained indicating that a* reduction was due to changes in the packaging effect. Below the euphotic layer, a* increased three-fold with respect to the DFM, which agrees with the expected accumulation of accessory pigments relative to chl a as an acclimation response to the low available irradiance. The most conspicuous change during the diurnal cycle was produced in the euphotic layer where the chl a concentration decreased significantly in the afternoon (from a mean concentration of 1.1 μg L−1 to 0.7 μg L−1) and increased at dusk when it averaged 1.4 μg L−1. In addition, a* and the blue-to-red absorption band ratio increased in the afternoon. These results suggest that a*(λ) diurnal variability was due to increase in photo-protective and accessory pigments relative to chl a. The variation ranges of a*(λ) at 675 and 440 nm (the absorption peaks in the red and blue spectral bands, respectively) in the euphotic layer were 0.01–0.04 and 0.02–0.10 m2 mg−1 chl a, respectively. Approximately 30% out of this variability can be attributed to the diurnal cycle. This factor should therefore be taken into account in refining primary production models based on phytoplankton light absorption. 相似文献
49.
C. Riedel A. Tryggvason B. Brandsdottír T. Dahm R. Stéfansson M. Hensch R. Böðvarsson K. S. Vogfjord S. Jakobsdottír T. Eken R. Herber J. Holmjarn M. Schnese M. Thölen B. Hofmann B. Sigurdsson S. Winter 《Marine Geophysical Researches》2006,27(4):267-281
Between June 2004 and September 2004 a temporary seismic network was installed on the northern insular shelf of Iceland and onshore in north Iceland. The seismic setup aimed at resolving the subsurface structure and, thus, the geodynamical transition from Icelandic crust to typical oceanic crust along Kolbeinsey Ridge. The experiment recorded about 1,000 earthquakes. The region encloses the Tjörnes Fracture Zone containing the Husavik–Flatey strike-slip fault and the extensional seismic Grimsey Lineament. Most of the seismicity occurs in swarms offshore. Preliminary results reveal typical mid-ocean crust north of Grimsey and a heterogeneous structure with major velocity anomalies along the seismic lineaments and north–south trending subsurface features. Complementary bathymetric mapping highlight numerous extrusion features along the Grimsey Lineament and Kolbeinsey Ridge. The seismic dataset promises to deliver new insights into the tectonic framework for earthquakes in an extensional transform zone along the global mid-ocean ridge system. 相似文献
50.
Determinations of copper consumption capacity (CuCs.C) and labile copper concentrations in surface coastal seawater, using a copper ion selective electrode (Cu-ISE) potentiometric method under predominantly diffusive conditions, are reported. For evaluation of the copper concentrations, the points of the endpoint contiguity zone of the CuCs.C titration curve were treated by an ISE multiple standard addition technique. The results were compared with those obtained by means of a Chelex-100 (calcic form) ‘batch’ procedure-potentiometric stripping analysis.The labile copper of the sample was determined at concentrations down to 10.70 nM with an average RSD of 12%, independent of the Cu-ISE employed. For adjacent subsamples, the mean CuCs.C values obtained for El Way seawater were equivalent to 81.05 and 48.00 nM copper, with an RSD of 4 and 7%, and for Isla Santa Maria seawater the value was equivalent to 70.27 nM copper, with an RSD of 7%. The theoretical approach of the electrode diffusive mechanism proposed, which would depend, fundamentally, on the adsorptive, complexing and reducing properties of the dissolved organic matter in the seawater sample, allows simultaneous analytical determination of CuCs.C and labile copper concentration in seawater. 相似文献