IAG Newsletter     

Ole Baltazar Andersen 《Journal of Geodesy》1996,70(9):591-598

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IAG Newsletter     

Ole Baltazar Andersen 《Journal of Geodesy》1996,70(8):529-531

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Organochlorine compound and trace metal contaminants in fish near Sydney's ocean outfalls     

Martin Krogh  Peter Scanes 《Marine pollution bulletin》1996,33(7-12):213-225

Sydney's inshore sewage outfalls were significant contributors to organochlorine contamination of inshore sedentary fish such as red morwong. Diversion of the sewage to deepwater outfalls has resulted in marked declines in the concentrations of these compounds in inshore red morwong. Apart from lead, however, similar trends did not occur for concentrations of trace metals. A wide variety of trace metals and organochlorine compounds were found in the flesh and/or livers of a variety of fish species caught at sites associated with the present deepwater ocean outfalls off Sydney. Fish caught at locations remote from Sydney also contained a wide variety of trace metals although organochlorine compounds were usually at lower levels. The mean contaminant levels in all species of offshore fish were generally found to be low when compared to the Australian National Food Authority's Maximum Residue Limit (NFA MRL). No fish analysed was found to have levels of an organochlorine compound above the MRL and no fish was found to have levels of zinc or lead above the MRL. When detected, fish with levels of a trace metal above the MRL appeared to be distributed throughout New South Wales, independent of the deepwater ocean outfalls off Sydney. There is no evidence as yet that the commissioning of the deepwater outfalls has led to an increase in levels of contaminants in the fish examined to the extent that they are of concern relative to the NFA MRLs.  相似文献   

Climatic change and design criteria in water resources management a regional case study     

Gerd Frch  Friedhelm Garbe  Jürgen Jensen 《Atmospheric Research》1996,42(1-4)

As a result of the anthropogenic greenhouse effect there is fear of alterations of the world climate, which also may result in hydrological changes and consequently in water resources management. In a case study it was investigated if such changes could be identified for a regional catchment area. Summarized it may be said that the regional analysis of hydro-meteorological data in the catchment area of the Sieg showed the expected effects of the anthropogenic climate change on the regional water cycle. Rises in annual mean temperature and precipitation could be observed over a period from 1892 until 1993. However, a significant relation between evident changes and greenhouse effect could not be stated. Changes in discharge do not show consistent behavior. Especially apparent contradictions show that additional examinations are necessary in order to make the complex natural inter-relationships between climate and regional water cycle with the impacts of existing anthropogenetic interferences visible and applicable for practical engineering tasks.  相似文献   

Comparison of surface meteorological measurements in TRACT database 4     

R. J. Barthelmie  N. O. Jensen 《Annales Geophysicae》1996,14(5):574-583

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Fracture induced emission of alkali atoms from feldspar     

J. T. Dickinson  L. C. Jensen  S. C. Langford  P. E. Rosenberg 《Physics and Chemistry of Minerals》1992,18(7):453-459

Emission of neutral atoms (K and Na) and molecules (H₂O and KOH) observed during fracture of K-feldspar have been accounted for by two independent mechanisms. H₂O and KOH emissions are attributed to the venting of fluid-filled inclusions, while emission of atomic K is due to surface effects accompanying cleavage of crystalline feldspar. The intensity of emitted potassium, at least 6 × 10¹⁴ atoms/cm² of surface area, is sufficient to affect K activities in solution during microbrecciation in the presence of rock-dominated fluids.  相似文献   

Phytoplankton and zooplankton of some lakes in northeastern Norway     

Ole A. Sæther 《Aquatic Sciences - Research Across Boundaries》1971,33(1):200-220

During the summer of 1966 some limnological aspects of thirteen lakes and one pond in the most northeasterly part of Norway were studied. A total of 418 taxa of algae including 104 genera, and 70 taxa of zooplankton including 46 genera are identified. The composition of the plankton in all the waters is shown to be typical for fundamentally oligotrophic lakes. A few of the lakes show some humic influence. This is in agreement with the hydrographic results from these waters (Bøyum [1]).  相似文献   

Sulfur isotopes of the Nairne Pyrite deposit,South Australia     

M. L. Jensen  A. W. G. Whittles 《Mineralium Deposita》1969,4(3):241-247

The Nairne Pyrite deposit occurs in at least five horizons in a succession of graywackes, quartzites, and siltstones of Cambrian age. Pyrite and pyrrhotite have been traced along bedding planes for almost 100 km suggesting, of course, a syngenetic origin for the sulfides. Sulfur isotopic analyses of samples from the Nairne Pyrite open-cut project provide S³⁴ values ranging from –12.8 to –20.6 permil. Such enrichment in S³², even though the spread in S³⁴ values is comparatively narrow, is suggestive of bacteriogenic sulfur which corroborates the geological evidence that the deposit is bacteriogenic — syngenetic in origin.

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Zusammenfassung Die Pyrit-Lagerstätte Nairne umfaßt wenigstens fünf Horizonte cambrischer Grauwacken, Quartzite und feine Sand- bis Tonsteine. Pyrit und Magnetkies sind über eine Distanz von fast 100 km schichtgetreu, was auf einen syngenetischen Ursprung der Sulfide hinweist. Schwefelisotop-Analysen von Pyrit aus dem Tagebau-Projekt erstrecken sich über einen S³⁴-Bereich von –12,8 bis –20,6 Promille. Diese Anreicherung weist auf einen bakteriellen Ursprung des Schwefels hin, obgleich die Spannweite der Resultate sehr eng ist. Somit ist die Feldvermutung einer syngenetisch-bakteriellen Entstehung bekräftigt.

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The isotopic analyses included in this paper were supported through the U. S. Atomic Energy Commission Contract AT (11-1) 1553, for which we are most grateful.  相似文献   

Geo-electrical investigations of Manganese ore bodies in India   总被引：1，自引：0，他引：1  

Jensen  K. D. 《Pure and Applied Geophysics》1954,28(1):91-108

Summary The Manganese ore-bodies in India are producing certain electrical potential-fields on the surface, which are typical for those deposits and which can exactly be surveyed by combined Potentiometer- and Resistivity-Method. The range of the relative Potentials, recorded so far, are generally varying between 150 to 200 millivolts, near deeper burried deposits accordingly lower but not lower than 100 millivolts, the relative resistivities varying from 50 to 400 megohms. The electrical surface indications are so clear that the respective position of an ore body can be located with an evident exactness as it is proved in this paper. Furthermore it is demonstrated how vaste geological areas can be prospected in a minimum of time by this method for the benefit of the mining industry.

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Zusammenfassung Die Manganerzkörper in Indien erzeugen an der Erdoberfläche elektrische Potentialfelder, die für die Lagerstätten typisch sind und durch kombinierte Potentiometer- und Widerstandsmessungen exakt aufgenommen werden können. Die bisher ermessenen Werte der relativen Potentiale bewegen sich zwischen allgemein 150 bis 200 Millivolt, bei tieferer Lage entsprechend niedriger, jedoch nicht unter 100 m V. Die scheinbaren Widerstände schwanken zwischen 50 und 400 megohm. Die elektrischen Oberflächenindikatoren sind so ausgeprägt, dass das Einschieben der Erzkörper mit beachtlicher Genauigkeit bestimmt werden kann wie in diesem Aufsatz nachgewiesen wird. Des weiteren wird dargetan, wie mittels dieses Verfahrens grosse geologische Räume in kürzester Zeit zum Nutzen des Erz-Bergbaues prospektiert werden können, wofür bislang noch keine geeignete Methode erprobt war.

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Two types of extremely short lasting decimetric bursts and their possible relation to processes in solar magnetic traps     

Øystein Elgarøy  Ole P. Sveen 《Solar physics》1973,32(1):231-240

High resolution spectral observations between 500 MHz and 550 MHz on 1972 October 25, revealed an emission event of special interest. The main feature was bursts with a single frequency duration of about 0.09 s and with a bandwidth of the same order of magnitude as the band covered by the spectrograph. The bursts occurred in showers' which lasted for one or two minutes and which were separated by quiet intervals of roughly the same length. Frequently the activity assumed a periodic nature. Periods between 0.1 s and 0.3 s were found. The most remarkable feature of the records was a very large number of bursts with the same duration as the wide band bursts, but showing a bandwidth of a mere 1–2 MHz.The wide band bursts may be plasma waves excited by proton streams trapped in coronal magnetic fields and the narrow band bursts may possibly be explained as perpendicular electrostatic electron cyclotron waves.  相似文献