Water source characterization through spatiotemporal patterns of major,minor and trace element stream concentrations in a complex,mesoscale German catchment     

Holger L. Fröhlich  Lutz Breuer  Hans‐Georg Frede  Johan A. Huisman  Kellie B. Vaché 《水文研究》2008,22(12):2028-2043

The link between spatiotemporal patterns of stream water chemistry and catchment characteristics for the mesoscale Dill catchment (692 km²) in Germany is explored to assess the catchment scale controls on water quality and to characterize water sources. In order to record the spatiotemporal pattern, ‘snapshot sampling’ was applied during low, mean and high flow, including 73 nested sites throughout the catchment. Water samples were analysed for the elements Li, B, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Mo, Ba, Pb and U using inductively‐coupled‐plasma mass spectrometry, and for electric conductivity and pH. Principle component analysis and hierarchical cluster analysis were used to find typical element associations and to group water samples according to their hydrochemical fingerprints. This revealed regional hydrochemical patterns of water quality which were subsequently related to catchment attributes to draw conclusions about the controls on stream chemistry. It was found that various lithologic signals and anthropogenic point source inputs controlled the base flow hydrochemistry. During increased flows, stream waters were diluted causing additional hydrochemical variability in response to heterogeneous precipitation inputs and differences in aquifer storage capacities. The hydrochemical patterns further displayed in‐stream mixing of waters. This implied, that stream waters could be apportioned to the identified water sources throughout the catchment. The basin‐wide hydrochemical variability has the potential to outrange the tracer signatures typically inferred in studies at the hillslope scale and is able to strongly influence the complexity of the catchment output. Both have to be considered for further catchment scale tracer and modelling work. Despite the likelihood of non‐conservative behaviour, the minor and trace elements enhanced the rather qualitative discrimination of the various groundwater types, as the major cations were strongly masked by point source inputs. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Observations of active galactic nuclei with the GT-48 CrAO gamma-ray telescope in 2004     

Yu. I. Neshpor  V. S. Eliseev  N. A. Jogolev  E. M. Nehay  Z. N. Skiruta  V. V. Fidelis  V. P. Fomin 《Bulletin of the Crimean Astrophysical Observatory》2007,103(1):16-20

Observations of several active galactic nuclei were performed with the GT-48 gamma-ray telescope at CrAO in 2004: 3C 66A, Mk 421, Mk 501, 1H 1426, 1ES 1959, and BL Lac. Very-high-energy (E ≥ 10¹² eV) gamma-ray fluxes were recorded from 3C 66A, Mk 421, Mk 501, and 1H 1426 at a confidence level of more than 4σ. Upper limits for the flux of very-high-energy gamma rays are presented for 1ES 1959 and BL Lac. The 2004 observational data for 3C 66A (z = 0.44) confirm the results obtained previously at CrAO.  相似文献   

The drift model of “magnetars”     

I. F. Malov  G. Z. Machabeli 《Astrophysics and Space Science》2007,308(1-4):467-469

It is shown that the drift waves near the light cylinder can cause the modulation of emission with periods of order several seconds. These periods explain the intervals between successive pulses observed in AXPs, SGRs and radio pulsars with long periods. The model under consideration gives the possibility to calculate real rotation periods P of host neutron stars. It is shown that P≤1 s for the investigated objects. The magnetic fields at the surface of the neutron star are of order 10¹¹–10¹³ G and equal to the fields usual for the known radio pulsars.   相似文献   

δ13C signature of early graphite and subsequently formed microdiamond from the Saxonian Erzgebirge,Germany     

Hans‐Joachim Massonne  Wenmao Tu 《地学学报》2007,19(6):476-480

Microdiamond and graphite occur in quartzofeldspathic rocks (saidenbachites) of the central Erzgebirge in Saxony. Zircon from such rocks contains not only relatively high but also variable amounts of early formed graphite and later crystallized diamond, however no carbonate. Six purified zircon concentrates were analysed by mass spectrometry for δ₁₃C(PDB) values which were between −24 and −33‰. The carbon inclusions resulted in C contents of the concentrates as high as 0.5 wt%. It is hypothesized that the observed δ₁₃C signature results from organic material in the sedimentary protoliths of the saidenbachites probably deposited not earlier than Mid‐Devonian. This material was transformed to graphite during early metamorphism and subsequently to diamond after an anatectic event at great depths (>150 km). During these processes, the δ₁₃C signature of the carbon did not (significantly) change.  相似文献   

Book reviews     

R. Herold  O. Müller  W. E. Petrascheck 《Mineralium Deposita》1976,11(2):246-247

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Klastische und pyroklastische Sedimente des Südharzer Rotliegenden     

Dr. Georg Müller 《Contributions to Mineralogy and Petrology》1962,8(6):440-490

Ohne Zusammenfassung  相似文献   

Investigation of groundwater residence times during bank filtration in Berlin: a multi‐tracer approach     

Gudrun Massmann  Jürgen Sültenfuß  Uwe Dünnbier  Andrea Knappe  Thomas Taute  Asaf Pekdeger 《水文研究》2008,22(6):788-801

Berlin relies on induced bank filtration from a broad‐scale, lake‐type surface water system. Because the surface water contains treated sewage, wastewater residues are present in surface water and groundwater. Multiple environmental tracers, including tritium and helium isotopes (³H, ³He, ⁴He), stable isotopes (δ¹⁸O and δ²H) and a number of persistent sewage indicators, such as chloride, boron and a selection of pharmaceutical residues (phenazone‐type analgesics and their metabolites, carbamazepine and anthropogenic gadolinium, Gd_excess), were used to estimate travel times from the surface water to individual production and observation wells at two sites. The study revealed a strong vertical age stratification throughout the upper aquifer, with travel times varying from a few months to several decades in greater depth. Whereas the shallow bank filtrate is characterized by the reflection of the time‐variant tracer input concentrations and young ³H/³He ages, the deeper, older bank filtrate displays no tracer seasonality, ³H/³He ages of a few years to decades and strongly deviating concentrations of several pharmaceutical residues, reflecting concentrations of the source surface water over time. The phenazone‐type pharmaceuticals persist in the aquatic environments for decades. Bank filtration in Berlin is only possible at the sandy lakeshores. In greater water depth, impermeable lacustrine sapropels inhibit infiltration. The young bank filtrate originates from the nearest shore, whereas the older bank filtrate infiltrates at more distant shores. This paper illustrates the importance of using multiple tracer methods, capable of resolving a broad range of residence times, to gain a comprehensive understanding of time‐scales and infiltration characteristics in a bank filtration system. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Reflection experiment on a floating ice platform     

Z. Hajnal  A. Overton 《Geophysical Journal International》1987,89(1):201-208

Summary. Preliminary analysis of a multifold seismic survey on a floating ice platform, northwest of Axel Heiberg Island, along the Canadian portion of the continental margin of the Arctic Ocean revealed a structurally complex basement at a depth beyond 4000 m. The basement is covered with high velocity (5000 m/sec) rock types. The results conform to the anticipated geologic model for regions of passive margins.  相似文献   

Le volcanisme aux Nouvelles Hébrides (Mélanésie)     

E. Aubert de la Rüe 《Bulletin of Volcanology》1937,2(1):79-142

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Further improvements to the higher-order Boussinesq equations: Bragg reflection     

Z.L. Zou  Z.B. Liu  K.Z. Fang 《Coastal Engineering》2009,56(5-6):672-687

Enhancements for the Bragg reflection are introduced for three sets of 2D higher order Boussinesq equations to improve the prediction of the Bragg reflection. The extension of the approach to other sets of Boussinesq equations is discussed. The analytical solutions for the Bragg reflection over an infinite number of sinusoidal bars are derived for these Boussinesq models and compared to the exact theoretical solution in order to determine the optimized values of the parameters in the new enhancement terms. Numerical simulations are also carried out for the Bragg reflection over a finite number of sand bars and compared with corresponding measurements to validate the enhancements. Comparisons with other forms of Boussinesq models are made to discuss the applicability of different forms of Boussinesq models to rapidly varying topography with sand bars. The effects of the mild slope assumption on the prediction of Bragg reflection and of wave reflection on a plane self are also discussed.  相似文献