Late Cretaceous structural control and Alpine overprint of the high-sulfidation Cu–Au epithermal Chelopech deposit, Srednogorie belt, Bulgaria     

Isabelle Chambefort  Robert Moritz 《Mineralium Deposita》2006,41(3):259-280

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Helmut Moritz 《Journal of Geodesy》1986,60(4):II

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Singularna izravnanja—Singular adjustment computations     

Helmut Moritz 《Journal of Geodesy》1986,60(4):II-II

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A general theory of gravity processing     

Helmut Moritz 《Studia Geophysica et Geodaetica》1970,14(2):221-222

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Sur la repartition de densite a l'interieur de l'ellipsoide equipotentiel     

H. Moritz 《Journal of Geodesy》1969,43(1):81-93

Résumé Une solution générale du problème de la répartition de densité à l'intérieur de l'ellipso?de équipotential est appliquée à quelques modèles spéciaux.

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A general solution of the problem of density distribution for the equipotential ellipsoid is applied to obtain some special models.

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Zusammenfassung Eine allgemeine L?sung des Problems der Massenverteilung für das Niveauellipsoid wird auf einige spezielle Modelle angewendet.

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A variational principle for Moledensky’s liquid-core problem     

Helmut Moritz 《Journal of Geodesy》1982,56(4):364-380

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The distribution of nitrate N/N in marine sediments and the impact of benthic nitrogen loss on the isotopic composition of oceanic nitrate     

Moritz F. Lehmann  Daniel M. Sigman  Julie Granger  Greg Cane 《Geochimica et cosmochimica acta》2007,71(22):5384-5404

We report ¹⁵N/¹⁴N ratios of porewater nitrate in sediments from the Bering Sea basin, where microbial nitrate reduction has been identified as a significant sink for fixed nitrogen (N). Strong ¹⁵N enrichment in porewater nitrate is observed as one goes deeper in the sediments and nitrate concentration decreases (δ¹⁵N generally reaches 25-35‰). Analysis of profiles with a one-dimensional diffusion-reaction model yields organism-scale isotope effects for dissimilatory nitrate reduction (ε_cell) of 11‰ to 30‰, in the same range as measured in previous studies of cultures and the marine and lacustrine water column. Estimates of ε_cell, while uncertain, show a negative correlation with bottom water [O₂]; we propose that this relates to the at the depth of denitrification. The N isotope effect at the scale of nitrate sediment-water exchange (ε_app) is ∼0‰ in two unreactive deep sites and is typically <3‰ at more reactive sites at various depths. ε_app is much lower than ε_cell because nitrate consumption is nearly complete at the sediment depth of denitrification, minimizing the escape of ¹⁵N-enriched nitrate from the sediments. In reactive sediments, this is due to rapid denitrification, while in less reactive sediments, it is due to greater diffusive distances for nitrate to the depth of denitrification. The data suggest that low bottom water [O₂] tends to yield more complete expression of ε_cell at the sediment-water scale, due to higher at the depth of denitrification. While porewater ammonium-N isotopes were not measured, our porewater model suggests that, in sediments with high organic matter supply and/or low-[O₂] bottom waters, the efflux and subsequent oxidation of ammonium enriched in ¹⁵N by incomplete nitrification can significantly enhance the total net isotope effect of sedimentary N loss (ε_sed, equivalent to ε_app but including ammonium fluxes). Model analysis of representative sedimentary environments suggests a global mean ε_sed of ∼4‰ (∼2‰ if restricted to seafloor below 1 km depth).  相似文献   

Evaluation of the third- and fourth-generation GOCE Earth gravity field models with Australian terrestrial gravity data in spherical harmonics   总被引：1，自引：1，他引：0  

Moritz Rexer  Christian Hirt  Roland Pail  Sten Claessens 《Journal of Geodesy》2014,88(4):319-333

In March 2013, the fourth generation of European Space Agency’s (ESA) global gravity field models, DIR4 (Bruinsma et al. in Proceedings of the ESA living planet symposium, 28 June–2 July, Bergen, ESA, Publication SP-686, 2010b) and TIM4 (Migliaccio et al. in Proceedings of the ESA living planet symposium, 28 June–2 July, Bergen, ESA, Publication SP-686, 2010), generated from the Gravity field and steady-state Ocean Circulation Explorer (GOCE) gravity observation satellite was released. We evaluate the models using an independent ground truth data set of gravity anomalies over Australia. Combined with Gravity Recovery and Climate Experiment (GRACE) satellite gravity, a new gravity model is obtained that is used to perform comparisons with GOCE models in spherical harmonics. Over Australia, the new gravity model proves to have significantly higher accuracy in the degrees below 120 as compared to EGM2008 and seems to be at least comparable to the accuracy of this model between degree 150 and degree 260. Comparisons in terms of residual quasi-geoid heights, gravity disturbances, and radial gravity gradients evaluated on the ellipsoid and at approximate GOCE mean satellite altitude ( $h=250$  km) show both fourth generation models to improve significantly w.r.t. their predecessors. Relatively, we find a root-mean-square improvement of 39 % for the DIR4 and 23 % for TIM4 over the respective third release models at a spatial scale of 100 km (degree 200). In terms of absolute errors, TIM4 is found to perform slightly better in the bands from degree 120 up to degree 160 and DIR4 is found to perform slightly better than TIM4 from degree 170 up to degree 250. Our analyses cannot confirm the DIR4 formal error of 1 cm geoid height (0.35 mGal in terms of gravity) at degree 200. The formal errors of TIM4, with 3.2 cm geoid height (0.9 mGal in terms of gravity) at degree 200, seem to be realistic. Due to combination with GRACE and SLR data, the DIR models, at satellite altitude, clearly show lower RMS values compared to TIM models in the long wavelength part of the spectrum (below degree and order 120). Our study shows different spectral sensitivity of different functionals at ground level and at GOCE satellite altitude and establishes the link among these findings and the Meissl scheme (Rummel and van Gelderen in Manusrcipta Geodaetica 20:379–385, 1995).  相似文献   

Trace element diffusion and incorporation in quartz during heating experiments     

B.?RottierEmail author  H.?Rezeau  V.?Casanova  K.?Kouzmanov  R.?Moritz  K.?Schl?glova  M.?W?lle  L.?Fontboté 《Contributions to Mineralogy and Petrology》2017,172(4):23

Heating of quartz crystals in order to study melt and high-temperature fluid inclusions is a common practice to constrain major physical and chemical parameters of magmatic and hydrothermal processes. Diffusion and modification of trace element content in quartz and its hosted melt inclusions have been investigated through step-heating experiments of both matrix-free quartz crystals and quartz crystals associated with sulfides and other minerals using a Linkam TS1500 stage. Magmatic and hydrothermal quartz were successively analyzed after each heating step for Cu, Al, and Ti using electron probe micro-analyzer. After the last heating step, quartz crystals and their hosted melt inclusions were analyzed by laser ablation inductively coupled plasma mass spectrometry and compared to unheated samples. Heated samples reveal modification of Cu, Li, Na, and B contents in quartz and modification of Cu, Li, Ag, and K concentrations in melt inclusions. Our results show that different mechanisms of Cu, Li, and Na incorporation occur in magmatic and hydrothermal quartz. Heated magmatic quartz records only small, up to a few ppm, enrichment in Cu and Na, mostly substituting for Li. By contrast, heated hydrothermal quartz shows enrichment up to several hundreds of ppm in Cu, Li, and Na, which substitute for originally present H. This study reveals that the composition of both quartz and its hosted melt inclusions may be significantly modified upon heating experiments, leading to erroneous quantification of elemental concentrations. In addition, each quartz crystal also becomes significantly enriched in Cu in the sub-surface layer during heating. We propose that sub-surface Cu enrichment is a direct indication of Cu diffusion in quartz externally sourced from both the surrounding sulfides as well as the copper pins belonging to the heating device. Our study shows that the chemical compositions of both heated quartz and its hosted inclusions must be interpreted with great caution to avoid misleading geological interpretations.  相似文献   

Finite locally resonant Metafoundations for the seismic protection of fuel storage tanks     

Francesco Basone  Moritz Wenzel  Oreste S. Bursi  Marinella Fossetti 《地震工程与结构动力学》2019,48(2):232-252

This paper introduces a novel seismic isolation system based on metamaterial concepts for the reduction of ground motion-induced vibrations in fuel storage tanks. In recent years, the advance of seismic metamaterials has led to various new concepts for the attenuation of seismic waves. Of particular interest for the present work is the concept of locally resonant materials, which are able to attenuate seismic waves at wavelengths much greater than the dimensions of their unit cells. Based on this concept, we propose a finite locally resonant Metafoundation, the so-called Metafoundation, which is able to shield fuel storage tanks from earthquakes. To crystallize the ideas, the Metafoundation is designed according to the Italian standards with conservatism and optimized under the consideration of its interaction with both superstructure and ground. To accomplish this, we developed two optimization procedures that are able to compute the response of the coupled foundation-tank system subjected to site-specific ground motion spectra. They are carried out in the frequency domain, and both the optimal damping and the frequency parameters of the Metafoundation-embedded resonators are evaluated. As case studies for the superstructure, we consider one slender and one broad tank characterized by different geometries and eigenproperties. Furthermore, the expected site-specific ground motion is taken into account with filtered Gaussian white noise processes modeled with a modified Kanai-Tajimi filter. Both the effectiveness of the optimization procedures and the resulting systems are evaluated through time history analyses with two sets of natural accelerograms corresponding to operating basis and safe shutdown earthquakes, respectively.  相似文献