The southeastern border of the Upper Rhine Graben: a 3D geological model and its importance for tectonics and groundwater flow     

Ina Spottke  Eric Zechner  Peter Huggenberger 《International Journal of Earth Sciences》2005,94(4):580-593

A 3D geological model of the area east of Basel on the southeastern border of the Upper Rhine Graben, consisting of 47 faults and six stratigraphic horizons relevant for groundwater flow, was developed using borehole data, geological maps, geological cross sections, and outcrop data. This model provides new insight into the discussions about the kinematics of the area between the southeastern border of the Upper Rhine Graben and the Tabular Jura east of Basel. A 3D analysis showed that both thin-skinned and thick-skinned tectonic elements occur in the modeled area and that the Anticline and a series of narrow graben structures developed simultaneously during an extensional stress-field varying from E–W to SSE–NNW, which lasted from the Middle Eocene to Late Oligocene. In a new approach the faults and horizons of the 3D geological model were transferred into discrete elements with distributed hydrogeological properties in order to simulate the 3D groundwater flow regime within the modeled aquifers. A three-layer approach with a horizontal regularly spaced grid combined with an irregular property distribution of transmissivity in depth permitted the piezometric head of the steady-state model to be automatically calibrated to corresponding measurements using more than 200 piezometers. Groundwater modeling results demonstrated that large-scale industrial pumping affected the groundwater flow field in the Upper Muschelkalk aquifer at distances of up to 2 km to the south. The results of this research will act as the basis for further model developments, including salt dissolution and solute transport in the area, and may ultimately help to provide predictions for widespread land subsidence risks.  相似文献   

The diameter and albedo of 1943 Anteros     

G.J. Veeder  E.F. Tedesco  D.J. Tholen  A. Tokunaga  G. Kowal  K. Matthews  G. Neugebauer  B.T. Soifer 《Icarus》1981,46(2):281-284

We report the results of broadband visual and infrared photometry of the Apollo-Amor asteroid 1943 Anteros during its 1980 apparition. By means of a radiometric model, we calculate a diameter of 2.3 ± 0.2 km and a visual geometric albedo of 0.13 ± 0.03. The albedo and reflectance spectrum of Anteros imply that it is a type S asteroid. Thus, Anteros may have a silicate surface similar to other Apollo-Amor asteroids as well as some stony-iron meteorites.  相似文献   

Mariner 10 infrared radiometer results: Temperatures and thermal properties of the surface of Mercury     

S.C. Chase  E.D. Miner  D. Morrison  G. Münch  G. Neugebauer 《Icarus》1976,28(4):565-578

Mariner 10 infrared brightness temperatures of the surface of Mercury at 11 and 45 μm are presented. The data were obtained during the first flyby along a nera-equatorial swath extending from 17 hours local time through local midnight to 9 hours local time. For an assumed emissivity of 0.9, derived surface thermal inertias are between $\text{0.0031}\text{and}\text{0.0031}\text{cal cm}{}^{\mathrm{?2}}\text{sec}{}^{\mathrm{<mtext>?1</mtext><mtext>2</mtext>}}\text{K}{}^{\mathrm{?1}}$ and the implied minimum predawn surface kinetic temperature for the warm pole at longitude 270° is near 93 K. Several pronounced thermal inhomogeneities were seen, one of which appears to coincide with a region of high radar reflectivity. The derived thermal properties and the electrical skin depth and loss tangent fall within the range of values found on the Moon.  相似文献   

Cryptotephras in the Lateglacial ICDP Dead Sea sediment record and their implications for chronology     

Ina Neugebauer  Daniela Müller  Markus J. Schwab  Simon Blockley  Christine S. Lane  Sabine Wulf  Oona Appelt  Achim Brauer 《Boreas: An International Journal of Quaternary Research》2021,50(3):844-861

Due to a lack of visible tephras in the Dead Sea record, this unique palaeoenvironmental archive is largely unconnected to the well-established Mediterranean tephrostratigraphy. Here we present first results of the ongoing search for cryptotephras in the International Continental Drilling Program (ICDP) sediment core from the deep Dead Sea basin. This study focusses on the Lateglacial (~15–11.4 cal. ka BP), when Lake Lisan – the precursor of the Dead Sea – shrank from its glacial highstand to the Holocene low levels. We developed a glass shard separation protocol and counting procedure that is adapted to the extreme salinity and sediment recycling of the Dead Sea. Cryptotephra is abundant in the Dead Sea record (up to ~100 shards cm^-3), but often glasses are physically and/or chemically altered. Six glass samples from five tephra horizons reveal a heterogeneous geochemical composition, with mainly rhyolitic and some trachytic glasses potentially sourced from Italian, Aegean and Anatolian volcanoes. Most shards likely originate from the eastern Anatolian volcanic province and can be correlated using major element analyses with tephra deposits from swarm eruptions of the Süphan Volcano ~13 ka BP and with ashes from Nemrut Volcano, presumably the Lake Van V-16 volcanic layer at ~13.8 ka BP. In addition to glasses that match the TM-10-1 from Lago Grande di Monticchio (15 820±790 cal. a BP) tentatively correlated with the St. Angelo Tuff of Ischia, we further identified a cryptotephra with glass analyses which are chemically identical with those of the PhT1 tephra in the Philippon peat record (13.9–10.5 ka BP), and also a compositional match for the glass analyses of the Santorini Cape Riva Tephra (Y-2 marine tephra, 22 024±642 cal. a BP). These first results demonstrate the great potential of cryptotephrochronology in the Dead Sea record for improving its chronology and connecting the Levantine region to the Mediterranean tephra framework.  相似文献   

Spectroscopic study of the Chemically Peculiar star HD 5797     

Ilian Kh. Iliev  Ina S. Barzova 《Astrophysics and Space Science》1993,206(2):249-257

Based on 19 spectrograms with a dispersion of 17.5 Å/mm, line spectrum variations in the CP2 star HD 5797 are studied. Equivalent width and central depth measurements show that intensities of 34 unblended lines vary with an amplitude of about 2 times for Fe, Ti and Sr lines, and 2.5 times for Cr lines. A search for improved period of the star has been carried out. The obtained new value is:P = 68.255 ± 0.004 days. An attempt to give a qualitative explanation of the photometric behaviour is made.  相似文献   

Solar wind interaction with Comet Bennett (1969i)     

L. F. Burlaga  J. Rahe  B. Donn  M. Neugebauer 《Solar physics》1973,30(1):211-222

This paper examines the relations between the solar-wind and Comet Bennett during the period March 23 to April 5, 1970. A large kink was observed in the ion tail of the comet on April 4, but no solar-wind stream was observed in the ecliptic plane which could have caused the kink. Thus, either there was no correlation between the solar wind at the Earth and that at Comet Bennett (which was 40° above the ecliptic) or the kink was caused by something other than a high-speed stream. The fine structure visible in photographs of the kink favors the second of these alternatives. It is shown that a shock probably passed through Comet Bennett on March 31, but no effect was seen in photographs of the comet. A stream preceded by another shock and a large abrupt change in momentum flux might have intercepted the comet between March 24 and March 28, but again no effect was seen in photographs of the Comet. In view of these results, one must seriously consider the possibility that a large, abrupt change in momentum flux of the solar-wind (such as that at a shock wave or ahead of a stream) is neither necessary nor sufficient to cause a large kink in a comet tail.On leave from Institute für Astrophysik Technische Universität Berlin West Germany.  相似文献   

On the ascent and emplacement of granitoid magma bodies dynamic-thermal numerical models     

Nina Kukowski  Horst J. Neugebauer 《International Journal of Earth Sciences》1990,79(2):227-239

The intrusion of granitoid magmas is understood as a lower and mid crustal process. Field observations and laboratory experiments give strong reason that most granitoid plutons are formed by diapiric ascent and emplacement of large magma bodies.On this basis, the ascent and emplacement of granitoid magmas is modelled by two-dimensional finite element calculations. The physical concept for this process provides convective transport of matter and heat, an isolated finite source region, variable source temperatures as well as variable density and viscosity contrasts.The model calculations show that the structural development of the model intrusion bodies is highly dependent on the physical properties of the magma and its surroundings. The most important among them are density and viscosity. Due to the different initial conditions, stocks of several plutons in the case of high viscosity contrast or flat magma sources as well as nappe-shaped intrusion structures as a result of low viscosity contrast can be understood by the intrusive mode of emplacement. The enlargement of the negative density contrast leads to an increase of the rate of ascent, so that more advanced intrusion structures are developed.

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Zusammenfassung Die Intrusion granitoider Magmen ist ein Prozeß der unteren und mittleren Kruste. Feldbefunde und Laboruntersuchungen geben Hinweise darauf, daß die meisten granitoiden Plutone durch diapirischen Aufstieg und Platznahme ausgedehnter Magmenkörper entstehen.Auf dieser Grundlage werden der Aufstieg und die Platznahme granitoider Magmen mit Hilfe von zweidimensionalen Finite Elemente Rechnungen modelliert. Das physikalische Konzept beinhaltet den konvektiven Transport von Masse und Energie, eine isolierte finite Quellregion, veränderliche Quelltemperaturen sowie einen variablen Dichte- und Viskositätskontrast.Die Modellrechnungen zeigen, daß die strukturelle Entwicklung der Modellmagmenkörper in hohem Maße von den physikalischen Parametern des Magmas und seiner Umgebung, vor allem Dichte und Viskosität, abhängt. Gemäß den unterschiedlichen Anfangsbedingungen können sowohl einige stockförmige Plutone im Falle eines hohen Viskositätskontrastes oder flacher Magmaquellen als auch deckenförmige Intrusionsstrukturen als Folge eines geringen Viskositätskontrastes mit Hilfe des intrusiven Einlagerungskonzeptes verstanden werden. Die Erhöhung des negativen Dichtekontrastes führt zu einer Erhöhung der Aufstiegsrate, so daß fortgeschrittenere Platznahmestrukturen erreicht werden können.

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Résumé L'intrusion des magmas granitoïdes est un processus qui intéresse la croûte inférieure et moyenne. Les observations de terrain et les expériences en laboratoire fournissent des arguments très sérieux en faveur de la formation des plutons par montée diapirique et mise en place de corps magmatiques de grandes dimensions.Sur base de cette conception, la montée et la mise en place de magmas granitoïdes a fait l'objet d'une modélisation par éléments finis à deux dimensions. Un tel modèle fait appel à un transport convectif de matière et de chaleur, à une région-source isolée de dimension finie, à une source de température variable ainsi qu' à divers contrastes de densité et de viscosité.Les calculs montrent que le développement structural des corps intrusifs ainsi modélisés dépend essentiellement des propriétés physiques du magma et de son encaissant, en particulier de la densité et de la viscosité. Etant données diverses conditions initiales, la modélisation rend compte de plusieurs types de culots plutoniques dans le cas de contrastes de viscosité élevés ou de sources de magma d'extension horizontale, ainsi que d'intrusions en forme de nappe dans le cas de faibles contrastes de viscosité. L'accroissement des contrastes de viscosité négatifs contribue à augmenter la vitesse d'ascension, ce qui permet le développement de structures d'intrusion plus évoluées.

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— , . , . . : , , . , , , . , , . .

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Notation a thermal expansion coefficient - C_p specific heat capacity - Di dissipation number (model specific) - g gravity acceleration - dynamic viscosity - h heigth of model - thermal diffusivity - Q heat flow - Ra Rayleigh number - R(v) differential operator - p density - t time - T absolute temperature - v velocity - V volume - w vertical component of velocity - x horizontal coordinate - stream function - z vertical coordinate  相似文献   

Drei Probleme der Echinodermendiagenese: Innere Zementation,Mikroporenbildung und der übergang von Magnesiumcalcit zu Calcit     

Prof. Dr. Joachim Neugebauer 《International Journal of Earth Sciences》1979,68(3):856-875

Zusammenfassung Die Echinodermen werden nach dem Konzept der Arbeitsrichtung Fossildiagenese auf drei Echinodermen-spezifische Probleme untersucht: 1. Syntaxiale Zementation: Der Beginn des Zementwachstums und die komplexe Verfüllung des inneren Hohlraums der Echinodermenkristalle wird anhand von Modellen, Experimenten und Geländeproben analysiert. 2. Mikroporen: Zementierte Echinodermenkristalle weisen im Innern Mikroporen auf, von denen es drei Typen mit verschiedener Entstehung gibt. Der Haupttyp der Mikroporen zeigt an, daß Lösungsprozesse bei der Fossilisation der Echinodermen verbreitet sind. 3. Magnesiumverlust: Mit Hilfe von Rasterelektronenmikroskopie und energiedispersiver Röntgenanalyse wird die mikroräumliche Verteilung des Magnesiums während des übergangs von Magnesiumcalcit zu Calcit untersucht. Es lassen sich nebeneinander Bereiche verschiedener Magnesiumverarmung nachweisen. Die Ergebnisse sprechen für den Prozeß der Calcitisierung (Lösung — Fällung) des Magnesiumcalcits bei seiner Umbildung.

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This study follows the concept of Fossildiagenese and examines specific diagenetic problems of systematic groups such as the echinoderms. Three problems are explored: 1. Syntaxial cementation: The beginning of the growth of cement and the complex filling of the inner space of the skeletal crystals is analysed using models, experiments, and field material. 2. Micropores: Cemented crystals of the echinoderms contain many small cavities called micropores. Three types of micropores formed by different processes are distinguished. One type of them gives evidence that dissolution occurs commonly in echinoderms during fossilization. 3. Loss of magnesium: BySem andEdax methods the microspatial distribution of the magnesium is examined during the transition from magnesian calcite to calcite and domains of different magnesium concentration close to each other are demonstrated. These domains are only compatible with the process of calcitization (dissolution — precipitation) of the magnesian calcite.

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Résumé Les échinodermes, ici étudiés suivant le concept de la «Diagénèse des fossiles», sont examinés par rapport aux trois problèmes qui leur sont spécifiques: 1. La cimentation syntaxiale: le commencement de la croissance du ciment et le remplissage complexe des vides internes du cristal que sont les échinodermes sont analysés à l'aide de modèles, d'expériences et d'échantillons du terrain. 2. Les micropores: les cristaux cimentés d'échinodermes montrent dans leur intérieur des micropores présentant trois types de formation différente. Le type principal montre que les processus de dissolution sont très répandus au cours de la fossilisation des échinodermes. 3. La perte de magnésium: la microscopie électronique à balayage et la methode «EDAX» permettent d'étudier la répartition microspatiale du magnésium pendant la transition de calcite magnésienne en calcite, montrant ainsi la juxtaposition de milieux à différents degrés d'appauvrissement en magnésium. Les résultats plaident en faveur d'un processus de calcitisation (solution-précipitation) de la calcite magnésienne au cours de la transformation.

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Long-term changes in physical and chemical conditions of nutrient-poor lakes along a latitudinal gradient: is there a coherent phytoplankton community response?     

Ina Bloch  Gesa A. Weyhenmeyer 《Aquatic Sciences - Research Across Boundaries》2012,74(1):77-85

To evaluate climate and atmospheric deposition induced physical and water chemical changes and their effects on phytoplankton communities, we used complete time series (14 years, monthly measurements during the growing season) of 18 physical and chemical variables and phytoplankton data from 13 nutrient-poor Swedish reference lakes along a latitudinal gradient. We found numerous strong significant changes over time that were most coherent among lakes for sulfate concentrations, conductivity, calcium, magnesium, chloride, potassium, water color, surface water temperature and the intensity of thermal stratification. Despite these pronounced coherent physical and water chemical changes over Sweden, the phytoplankton biomass and species richness of six phytoplankton groups, measured at the same time as the water chemical variables, showed only few and weak significant changes over time. The only coherent significant change over Sweden, occurring in seven lakes, was observed in the species richness of chlorophytes. The number of chlorophyte taxa significantly declined over Sweden. Using a partial least square model for each lake, we attributed the decline primarily to an increase in water temperatures and water color, which were among the most important variables for the model performance of each lake. All other taxonomic groups were driven primarily by non-coherent changes in nutrient concentrations, pH and probably also non-coherent grazing pressure. We concluded that coherent phytoplankton responses can only be achieved for taxonomic groups that are driven primarily by coherent physical/chemical changes. According to our study, chlorophytes belong to such a group, making them possible global change indicators. Our findings give new insights into global change effects on different phytoplankton taxonomic groups in nutrient-poor lakes.  相似文献   

The 1895 Ljubljana earthquake: can the intensity data points discriminate which one of the nearby faults was the causative one?     

Lara Tiberi  Giovanni Costa  Petra Jamšek Rupnik  Ina Cecić  Peter Suhadolc 《Journal of Seismology》2018,22(4):927-941

The earthquake (Mw 6 from the SHEEC defined by the MDPs) that occurred in the central part of Slovenia on 14 April, 1895, affected a broad region, causing deaths, injuries, and destruction. This event was much studied but not fully explained; in particular, its causative source model is still debated. The aim of this work is to contribute to the identification of the seismogenic source of this destructive event, calculating peak ground velocity values through the use of different ground motion prediction equations (GMPEs) and computing a series of ground motion scenarios based on the result of an inversion work proposed by Juki? in 2009 and on various fault models in the surroundings of Ljubljana: Vi?, ?elimlje, Borovnica, Vodice, Ortnek, Mi?jedolski, and Dobrepolje faults. The synthetic seismograms, at the basis of our computations, are calculated using the multi-modal summation technique and a kinematic approach for extended sources, with a maximum peak ground velocity value of 1 Hz. The qualitative and quantitative comparison of these simulations with the macroseismic intensity database allows us to discriminate between various sources and configurations. The quantitative validation of the seismic source is done using ad hoc ground motion to intensity conversion equations (GMICEs), expressly calculated for this study. This study allows us to identify the most probable causative source model of this event, contributing to the improvement of the seismotectonic knowledge of this region. The candidate fault that has the lowest values of average differences between observed and calculated intensities and chi-squared is a strike slip fault with a toward-north rupture as the Ortnek fault.  相似文献