The Moho Structure in The Western Eger Rift: A Receiver Function Experiment     

Geissler  Wolfram  Plenefisch  Thomas  Kind  Reiner  Klinge  Klaus  Kämpf  Horst  Boušková  Alena  Nehybka  Vladimír  Skácelová  Zuzana  Jacob  Brian 《Studia Geophysica et Geodaetica》2000,44(2):188-194

We used teleseismic recordings of a temporary deployment of seismic stations and of permanent short period stations in the western Eger Rift system to study the lithosphere with the help of Receiver Functions. The crust-mantle boundary (Moho) is observed at almost all stations by strong P-to-S converted phases. The Moho is basically flat between about 26 – 30 km depth in the entire region. At one station in the Eger Rift (BOH-1, Loket castle) no Moho is observed. We interpret this with the existence of a broad gradient zone there, instead of a sharp discontinuity. This observation, however, needs to be confirmed by more data.  相似文献   

Sewer model development under minimum data requirements   总被引：1，自引：1，他引：0  

Frank Blumensaat  Martin Wolfram  Peter Krebs 《Environmental Earth Sciences》2012,65(5):1427-1437

Planning, design and operation of urban drainage systems is often based on hydraulic sewer modelling. Sewer models are also increasingly used to quantify pollution loads discharged to aquatic ecosystems (e.g. via combined sewer overflows), which ultimately allows an estimation of the ecological impact emanating from urban drainage systems. The establishment of such network models, however, requires detailed and accurate information about the sewer network structure and the connected surface area. This infrastructure data is often unavailable, confidential or available in ‘paper’ format only. The present paper outlines a novel approach to develop a hydraulic sewer model constrained by a minimum amount of data. The approach combines the application of a surface flow accumulation algorithm to a selectively manipulated Digital Elevation Model (DEM) with a routine for hydraulic network dimensioning to generate a close-to-reality sewer network ready to be implemented in a hydraulic modelling platform. The method is tested for three real-life catchments of which characteristics vary in scale, topography, state of development and network complexity. For all cases the generated network is implemented on the EPA-SWMM platform to allow hydrodynamic simulations. Model performance is assessed by (1) evaluating the spatial match of existing and generated network layout, (2) comparing the estimated hydraulic dimension with real-life infrastructure data and (3) benchmarking simulated runoff with measured data for a defined validation period. The analysis shows that the presented method is capable of reproducing the original network layout, network length and corresponding discharge rates based on little, freely available information. Further research potential is identified to improve the hydraulic dimensioning and the application to complex systems that include control structures. The presented approach is useful to estimate the scope of drainage networks including layout and design (e.g. for preliminary planning in emerging areas) to screen existing networks and to identify critical spots where more precise information is required.  相似文献   

Commodity conservation: The restructuring of community conservation in South Africa and the Philippines     

Bram Büscher  Wolfram Dressler 《Geoforum》2012,43(3):367-376

The world over, neoliberal modes of conservation are hybridising with, or even replacing, other forms of conservation. Under the banner of ‘win–win’ policies, planners actively work to commoditize natural resources and the social relations that determine the use and conservation of these resources. While these general processes seem to hold sway globally, it is crucial not to lose sight of the context specific ways in which neo-liberalism influences conservation practice and local outcomes. The paper examines how neo-liberalism’s global pervasiveness becomes manifest across different levels and scales in South Africa and the Philippines. The conclusion suggests that as a result of these neoliberal pressures, emphasis is shifting from local constructions of ‘nature’ by communities to what the environment should mean for communities in terms of commodified resources and growing capitalist markets.  相似文献   

Darss Sill as a biological border in the fossil record of the Baltic Sea: evidence from diatoms   总被引：1，自引：0，他引：1  

Andrzej Witkowski  Anja Broszinski  Ole Bennike  Beata Janczak-Kostecka  Jrn Bo Jensen  Wolfram Lemke  Rudi Endler  Antoon Kuijpers 《Quaternary International》2005,130(1):97

Biostratigraphical and palaeoecological analyses of cores along a transect from Femer Belt to the Arkona Basin reveal that North Sea waters began to enter the western Baltic Sea between 8600 and 8400 calibrated years BP. Studies of diatoms indicate that Mecklenburg Bay was characterised by slightly brackish-water conditions between 8400 and 8000 cal. years BP. At around 8000 cal. years BP increasing salinity is indicated by a strong dominance of the diatoms Paralia sulcata and Dimeregramma minor. Some centuries later another diatom assemblage appeared and became dominant in Mecklenburg Bay. This assemblage includes Hyalinella lateripunctata and Pravifusus hyalinus species typical of shallow water areas along the Atlantic coast today. At this time the first marine molluscs made their appearance. The oldest shell of a marine mollusc found in our material is dated to 7600 cal. years BP. The associated assemblage that includes adult specimens of the gastropod Aporrhais pespelicani indicates higher salinities than today.During the Littorina Sea stage a marine diatom flora with P. sulcata, Catenula adhaerens and D. minor crossed the Darss Sill and became widely distributed in the Arkona Basin, Pomeranian Bay and the Baltic Sea proper. In contrast, taxa indicative of the Hyalinella lateripunctata/P. hyalinus assemblage are only found west of the Darss Sill in Femer Belt and Mecklenburg Bay. Apparently, the Darss Sill threshold has been acting as an important salinity border from around 7800 cal. years BP until today.  相似文献   

Diel Activity Patterns and Foraging Dynamics of the Sea Urchin Tripneustes ventricosus in a Tropical Seagrass Community and a Reef Environment (Virgin Islands)     

Wolfram P. Tertschnig 《Marine Ecology》1989,10(1):3-21

Abstract. Feeding and movement activity patterns and the foraging behavior of the sea urchin Tripneustes ventricosus were investigated in a Thalassia testudinum seagrass bed and on a patch reef at St. Croix, U.S. Virgin Islands.
Most of T. ventricosus in the seagrass bed fed during both the day and night. Consumption of seagrass blades amounted to 1.4 g dw · individual^-1· d^-1 (mean sea urchin size 12.1 cm ambitus diameter). The population consumed approximately 3.6% of the daily seagrass production.
The movement of T. ventricosus was diel with high nocturnal activity levels and rates of locomotion, and little activity during daylight hours. Foraging activity was reduced under turbulent conditions. Movement rates were not governed by food availability. T. ventricosus travelled 3.7 m · d^-1 on the patch reef. Individuals in the seagrass bed moved 8.8 m · d^-1, most of which was accomplished during the night. The area traversed contained more than one hundred times the amount of food consumed daily. It is assumed that this behavior requires high energy expenditures for locomotion, thus yielding a low net energy profit from feeding.
The high rate of movement in seagrass beds may represent an innate behavioral adaptation to predation by night-active helmet conchs ( Cassis spp.). Fitness optimization by T. ventricosus may have been achieved by minimizing the predation risk during night hours. In an evolutionary context, survival by means of an increased energy expenditure for locomotion may compensate for the lower net energy gain from foraging.  相似文献   

An Observational Case Study on the Influence of Atmospheric Boundary-Layer Dynamics on New Particle Formation     

Andreas Platis  Barbara Altstädter  Birgit Wehner  Norman Wildmann  Astrid Lampert  Markus Hermann  Wolfram Birmili  Jens Bange 《Boundary-Layer Meteorology》2016,158(1):67-92

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Waste Heat Balance in Aquifers Calculated by a Computer Programme     

Wolfram Kley  Winfried Heekmann 《Ground water》1981,19(2):144-148

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Modeling insulated borehole heat exchangers     

Daniel Otto Schulte  Bastian Welsch  Anke Boockmeyer  Wolfram Rühaak  Kristian Bär  Sebastian Bauer  Ingo Sass 《Environmental Earth Sciences》2016,75(10):910

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Loughlinit (Na-Sepiolith) und Analcim in neogenen Sedimenten Anatoliens     

Wolfram Echle 《Contributions to Mineralogy and Petrology》1967,14(2):86-101

Zusammenfassung Der Mineralbestand von Proben aus einem miozänen Tonhorizont der anatolischen Neogenformation bei Killik, Vilayet Eskiehir (Türkei), wird beschrieben und genetisch gedeutet. Hauptkomponenten bilden die Assoziationen Loughlinit-Analcim und Sepiolith-Analcim. Daneben sind Montmorillonit, Dolomit, Pyrit, Gips und — bei Anwesenheit von Loughlinit — wasserlösliche Na-Salze unbekannter Zusammensetzung vorhanden. Der Ton stellt das zweite bisher bekannte Loughlinitvorkommen dar. Analcim, Loughlinit und Sepiolith werden als diagenetische Bildungen im Sediment unter maßgeblicher Beteiligung Na- und Mg-reicher Porenwässer gedeutet. Die Möglichkeiten der Genese dieser Minerale werden durch Vergleich mit anderen Vorkommen und unter Berücksichtigung der geologischen Gegebenheiten diskutiert. Voraussetzung für die Bildung dieser Silikate ist ein enormes Na-Angebot aus einem eindampfenden Meeresbecken und/oder aus der Zersetzung sauren vulkanischen Materials und gleichzeitige Anlieferung von Mg, Al, Si in Form von Lösungen oder Detritus. Als wichtigste Liefergesteine werden die an den ehemaligen Beckenrändern verbreitet auftretenden Serpentinite betrachtet.

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The mineral content of specimens from a miocene clay horizon of the Anatolic Neogen formation near Killik, Vilayet Eskiehir (Turkey), has been described and a genetic interpretation has been given. The main components are the associations loughlinite-analcime and sepiolite-analcime. There are further montmorillonite, dolomite, pyrite, gypsum and watersoluble sodium salts of unknown composition, but the last ones apperently only if there is loughlinite. This clay is the second known occurrence of loughlinite. Analcime, loughlinite and sepiolite may have formed during diagenesis with an intensive interaction of sodium and magnesium rich pore solutions. The possibilities of the origin of these minerals have been discussed by comparing this occurrence with others and considering the geological environment.

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Frau Prof. Dr. D. Schachner danke ich für die Förderung der Arbeit und die Erlaubnis, die von der Deutschen Forschungsgemeinschaft zur Verfügung gestellte Röntgenapparatur benutzen zu können.  相似文献   

Upper mantle and lithospheric heterogeneities in central and eastern Europe as observed by teleseismic receiver functions     

Wolfram H. Geissler  Rainer Kind  Xiaohui Yuan 《Geophysical Journal International》2008,174(1):351-376

Data from 90 permanent broad-band stations spread over central and eastern Europe were analysed using Ps receiver functions to study the crustal and upper-mantle structure down to the mantle transition zone. Receiver functions provide valuable information on structural features, which are important for the resolution of European lithospheric dynamics. Moho depths vary from less than 25 km in extensional areas in central Europe to more than 50 km at stations in eastern Europe (Craton) and beneath the Alpine–Carpathian belt. A very shallow Moho depth can be observed at stations in the Upper Rhine Graben area ( ca. 25 km), whereas, for example, stations in the SW Bohemian Massif show a significantly deeper Moho interface at a depth of 38 km. V_p / V_s ratios vary between 1.60 and 1.96, and show no clear correlation to the major tectonic units, thus probably representing local variations in crustal composition. Delayed arrivals of converted phases from the mantle transition zone are observed at many stations in central Europe, whereas stations in the cratonic area show earlier arrivals compared with those calculated from the IASP91 Earth reference model. Differential delay times between the P₄₁₀s and P₆₆₀s phases indicate a thickened mantle transition zone beneath the eastern Alps, the Carpathians and the northern Balkan peninsula, whereas the transition zone thickness in eastern and central Europe agrees with the IASP91 value. The thickening of the mantle transition zone beneath the eastern Alps and the Carpathians could be caused by cold, deeply subducted oceanic slabs.  相似文献