Feasibility of utilizing wavelet phase to map the CO2 plume at the Ketzin pilot site,Germany          下载免费PDF全文

Fei Huang  Christopher Juhlin  Li Han  Daniel Sopher  Monika Ivandic  Ben Norden  Wubing Deng  Fengjiao Zhang  Thomas Kempka  Stefan Lüth 《Geophysical Prospecting》2017,65(2):523-543

Spectral decomposition is a powerful tool that can provide geological details dependent upon discrete frequencies. Complex spectral decomposition using inversion strategies differs from conventional spectral decomposition methods in that it produces not only frequency information but also wavelet phase information. This method was applied to a time‐lapse three‐dimensional seismic dataset in order to test the feasibility of using wavelet phase changes to detect and map injected carbon dioxide within the reservoir at the Ketzin carbon dioxide storage site, Germany. Simplified zero‐offset forward modelling was used to help verify the effectiveness of this technique and to better understand the wavelet phase response from the highly heterogeneous storage reservoir and carbon dioxide plume. Ambient noise and signal‐to‐noise ratios were calculated from the raw data to determine the extracted wavelet phase. Strong noise caused by rainfall and the assumed spatial distribution of sandstone channels in the reservoir could be correlated with phase anomalies. Qualitative and quantitative results indicate that the wavelet phase extracted by the complex spectral decomposition technique has great potential as a practical and feasible tool for carbon dioxide detection at the Ketzin pilot site.  相似文献   

Evaluating the Precise 39Ar/40Ar Dating of Multiple Mineral Potassic Phases in Ultra-alkaline Rocks: Applications to Mantle Systematics     

Simon A. WILDE  Fred JOURDAN  Lynda FREWER  Monika A. KUSIAK 《《地质学报》英文版》2020,94(Z1):50-50

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Mineral fibres and environmental monitoring:A comparison of different analytical strategies in New Caledonia     

Jasmine Rita Petriglieri  Christine Laporte-Magoni  Peggy Gunkel-Grillon  Mario Tribaudino  Danilo Bersani  Orietta Sala  Monika Le Mestre  Ruggero Vigliaturo  Nicola Bursi Gandolfi  Emma Salvioli-Mariani 《地学前缘(英文版)》2020,11(1):189-202

Covered by ultrabasic units for more than a third of its surface,the New Caledonia(South West Pacific)is one of the largest world producers of Ni-ore from lateritic deposits.Almost all outcrops of geological units and open mines contain serpentine and amphibole,also as asbestos varieties.In this geological context,in which weathering processes had a great contribution in the production and dispersion of mineral fibres into the environment,the development of a routinely analytical strategy,able to discriminate an asbestiform fibre from a non-harmful particle,is a pivotal requisite.However,the acquisition of all these parameters is necessary for determining the risk associated to fibres exposition.A multidisciplinary routinely approach,based on the use of complementary simply-to-use but reliable analytical methods is the only possible strategy.In addition,the instrumental apparatus must be easily transportable on the field,directly on the mining site.The employment of specialized tools such as Polarized Light Microscopy associated to Dispersion Staining method(PLM/DS)and portable Raman spectroscopy for identification of environmental asbestos,are proved extremely effective in the improvement of the performance and rapidity of data acquisition and interpretation.Both PLM/DS and handheld Raman devices confirmed to be discriminant in the detection and characterization of asbestos fibres for both serpentine and amphibole.Furthermore,these techniques proved extremely effective even in the presence of strongly fibrous and altered samples.  相似文献   

Phosphorus input by upwelling in the eastern Gotland Basin (Baltic Sea) in summer and its effects on filamentous cyanobacteria     

Monika Nausch  Günther Nausch  Hans Ulrich Lass  Volker Mohrholz  Klaus Nagel  Herbert Siegel  Norbert Wasmund   《Estuarine, Coastal and Shelf Science》2009,83(4):434-442

In July 2007, phosphorus input by an upwelling event along the east coast of Gotland Island and the response of filamentous cyanobacteria were studied to determine whether introduced phosphorus can intensify cyanobacterial bloom formation in the eastern Gotland Basin. Surface temperature, nutrient concentrations, phytoplankton biomass and its stoichiometry, as well as phosphate uptake rates were determined in two transects between the coasts of Gotland and Latvia and in a short grid offshore of Gotland. In the upwelling area, surface temperatures of 11–12 °C and average dissolved inorganic phosphorus (DIP) concentrations of 0.26 μM were measured. Outside the upwelling, surface temperatures were higher (15.5–16.6 °C) and DIP supplies in the upper 10 m layer were exhausted. Nitrite and nitrate concentrations (0.01–0.22 μM) were very low within and outside the upwelling region. Abundances of filamentous cyanobacteria were highly reduced in the upwelling area, accounting for only 1.4–6.0% of the total phytoplankton biomass, in contrast to 18–20% outside the upwelling. The C:P ratio of filamentous cyanobacteria varied between 32.8 and 310 in the upwelling region, most likely due to the introduction of phosphorus-depleted organisms into the upwelling water. These organisms accumulate DIP in upwelling water and have lower C:P ratios as long as they remain in DIP-rich water. Thus, diazotrophic cyanobacteria benefit from phosphorus input directly in the upwelling region. Outside the upwelling region, the C:P ratios of filamentous cyanobacteria varied widely, between 240 and 463, whereas those of particulate material in the water ranged only between 96 and 224. To reduce their C:P ratio from 300 to 35, cyanobacteria in the upwelling region had to take up 0.05 mmol m⁻³ DIP, which is about 20% of the available DIP. Thus, a larger biomass of filamentous cyanobacteria may be able to benefit from a given DIP input. As determined from the DIP uptake rates measured in upwelling cells, the time needed to reduce the C:P ratio from 300 to 35 was too long to explain the huge bloom formations that typically occur in summer. However, phosphorus uptake rates increased significantly with increasing C:P ratios, allowing phosphorus accumulation within 4–5 days, a span of time suitable for bloom formation in July and August.  相似文献   

Festkontaktierte potentiometrische Elektroden für Sulfatbestimmungen in wässrigen Lösungen     

Monika Berthold  Heimo Jahn  Heiner Kaden 《洁净——土壤、空气、水》2001,29(4):219-226

Solid‐contacted Potentiometric Electrodes for Measurements of Sulfate Ions in Aqueous Solutions A solid‐contact electrode for potentiometric measurement of sulfate ions in aqueous solutions was developed and examined. The electrode is based on a PVC membrane which contains the ionophore 3‐decyl‐1,5,8‐triazacyclodecan‐2,4‐dione (DTADD). Instead of the usual inner fluid junction, a polypyrrole layer applied on the inner side of the PVC membrane was employed as inner solid contact. The performance of this electrode was compared to solid‐state sulfate‐selective electrodes with the ionophore α,α′‐bis(N′‐phenylthioureylene)‐m‐xylene (BTH) and to electrodes in the coated‐wire configuration. For the parameters sensitivity, selectivity, and long‐term stability, electrodes with the DTADD ionophore show improved properties. In the sulfate concentration range of 5·10^–5...10^–2 mol L^–1 the slope of the response is –(26.8 ± 0.5) mV/decade. The new solid contact sulfate electrodes showed a very low drift of the electrode potential within a period of 150 days when the electrode was stored in 10^–2 M Na₂SO₄. In Na2SO4 solutions of the pH range of 4...9 the electrode potentials were constant. The 95% response time was about 10 s when the sulfate concentration was changed from 10^–4 mol L^–1 to 10^–3 mol L^–1. The selectivity with DTADD ionophore relating to the nitrate ions is higher than the selectivity with BTH. Improvements are also made in comparison with sulfate‐selective electrodes described in the literature which contain other ionophores with fluid inner reference electrolytes.  相似文献   

High-resolution seabed imagery as a tool for biodiversity conservation planning on continental margins     

Thomas A. Schlacher  Alan Williams  Franziska Althaus  & Monika A. Schlacher-Hoenlinger 《Marine Ecology》2010,31(1):200-221

Submarine canyons increase seascape diversity on continental margins and harbour diverse and abundant biota vulnerable to fishing. Because many canyons are fished, there is an increasing emphasis on including them in conservation areas on continental margins. Here we report on sponge diversity and bottom cover in three canyons of South-eastern Australia, test the performance of biological and abiotic surrogates, and evaluate how biological data from detailed seabed surveys can be used in conservation planning in these habitats. The biological data on sponge assemblage structure and species richness were obtained from 576 seafloor images taken between 148 and 472 m depth, yielding 65 morphospecies. Seafloor characteristics were similar within and between canyons, being almost exclusively composed of sediments with very few rocky substrates of higher relief. This environmental homogeneity did not, however, translate into biological uniformity of the megabenthos, and environmental factors were consequently poor predictors of biological features. By contrast, total bottom cover of sponges was highly correlated with species richness and served as a good proxy for species-level data in this situation. Design strategies that employ information on cover or richness of sponges provided a large dividend in conservation effort by dramatically reducing the number of spatial units required to achieve a specified conservation target of 50–90% of species to be included in reserves. This demonstrates that image-derived data are useful for the design of reserves in the deep sea, particularly where extractive sampling is not warranted. Using biological data on the sponge megabenthos to identify conservation units can also minimise socio-economic costs to fisheries because of a smaller geographic and bathymetric ambit of conservation areas.  相似文献   

An automated full waveform logging system for high-resolution P-wave profiles in marine sediments     

Monika Breitzke  Volkhard Spieβ 《Marine Geophysical Researches》1993,15(4):297-321

An automated, PC-based logging system has been developed to investigate marine sediment cores by full waveform transmission seismograms. High-resolution P-wave velocity and amplitude attenuation profiles are simultaneously derived from the transmission data to characterize the acoustic properties of the sediment column.A pair of ultrasonic, piezoelectric wheel probes is used to generate and record the transmission signals travelling radially through the sediment core. Both unsplit and split cores are allowed. Mounted in a carriage driven by a stepping motor via a shaft the probes automatically move along the core liner, stopping at equidistant spacings to provide a quasi-continuous inspection of the core by the transmission data. The axial travel distance and the core diameter are determined by digital measuring tools.First arrivals are picked automatically from the transmission seismograms using either a threshold in the seismogram's envelope or a cross-correlation algorithm taking the zero-offset signal of both wheel probes into account. Combined with the core diameter these first arrivals lead to a P-wave velocity profile with a relative precision of 1 to 2 m s^–1. Simultaneously, the maximum peak-to-peak amplitudes of the transmission seismograms are evaluated to get a first idea on the amplitude attenuation along the sediment core.Two examples of gravity cores taken during a recent cruise of R.V. METEOR in the Western Equatorial Atlantic are presented. They yield that the P-wave profiles can be used for locating strong and fine-scale lithological changes, e.g. turbidite layers and slight variations in the sand, silt or clay content. In addition, the transmission seismograms and their amplitude spectra obviously seem to reveal a correlation between the relative amount of low-frequency spectral components and the sediment grain size, and thus provide a tool for the determination of additional, related physical or sedimentological parameters in future investigations.  相似文献   

17th International Cartographic Conference 10th General Assembly of ICA     

Frauke Heinzle  Karl-Heinrich Anders  Monika Sester 《GeoJournal》1994,34(2):234-234

Reports

17th International Cartographic Conference 10th General Assembly of ICA  相似文献   

EPMA and PIXE dating of monazite in granulites from Stary Gierałtów, NE Bohemian Massif, Poland     

Monika A. Kusiak  Kazuhiro Suzuki  Daniel J. Dunkley  Janusz Lekki  Nonna Bakun-Czubarow  Mariusz Paszkowski  Bartosz Budzy&#x; 《Gondwana Research》2008,14(4):675

Chemical Th–U–total Pb (CHIME) dating of monazite by electron probe microanalyzer (EPMA) and proton microprobe (PIXE) was carried out on felsic granulites from Stary Gierałtów, Poland, which represent part of the Orlica-Śnieżnik Dome in the NE Bohemian Massif. Analyzed monazite is characterized by mosaic zoning rather than simple core-to-rim growth, and strontium contents of up to 750ppm. An isochron age of 347 ± 13Ma represents timing of amphibolite-facies metamorphism, in agreement with previously published estimates.  相似文献   

An Automated Iridium-Strip Heater for LA-ICP-MS Bulk Analysis of Geological Samples   总被引：1，自引：0，他引：1  

Brigitte Stoll  Klaus Peter Jochum  Kirstin Herwig  Marghaleray Amini  Michael Flanz  Berthold Kreuzburg  Dmitry Kuzmin  Matthias Willbold  Jacinta Enzweiler 《Geostandards and Geoanalytical Research》2008,32(1):5-26

In this paper we describe a flux‐free fusion technique for the highly precise LA‐ICP‐MS bulk analysis of geological samples. For this purpose we have developed an automated iridium‐strip heater with temperature and melt time control. To optimise the homogeneity of the fused glasses and to reduce possible depletion of volatile elements during melting, we undertook experiments with basaltic rock and glass powders using different melting temperatures (1300–1700 °C) and melting times (5‐80 s). Major and trace element microanalysis was performed using EPMA and LA‐ICP‐MS. Homogeneous glasses were obtained for temperatures ≥ 1500 °C and melting times ≥ 10 s. High loss (20‐90%) of highly volatile elements (e.g., Cs, Ge, Sn, Pb) was observed for high melting temperatures (≥ 1600 °C) and long melting times (80 s). Standard melting conditions (1600 °C, 10 s) represent a compromise, as the glasses were homogeneous with respect to major and trace elements and, at the same time, were not depleted in elements with condensation temperatures (at a pressure of 10^?4 bar) higher than about 900 K (e.g., Zr, Hf, Ba, Sr, REE, U, Mo, Ni, Rb, Ga). Several international geological reference materials with SiO₂ ranging between 47% m/m and 59% m/m were prepared using our standard melting conditions (1600 °C, 10 s) and subsequently analysed by LA‐ICP‐MS. These samples also include the new Brazilian basaltic reference material BRP‐1. Matrix‐matched calibration of the LA‐ICP‐MS data was performed using the basaltic reference glasses KL2‐G, ML3B‐G, BCR‐2G and BHVO‐2G. Most analytical data agreed within uncertainty at the 95% confidence level with the GeoReM preferred values published in the GeoReM database for reference materials of geological and environmental interest. To demonstrate routine bulk LA‐ICP‐MS analyses of geochemical and cosmochemical samples using the whole rock fusion technique, we also present trace element data for ocean island basalts from Lanai (Hawaii) and of Martian meteorites.  相似文献