Milankovic’s theory: multidimensional visualisation of the change of insolation and indicators of climatic change from 100000 before present to 100000 after present (in intervals of 1,000 years)     

Ulrich Wieczorek 《International Journal of Earth Sciences》2010,99(1):201-205

The deviation of the insolation on the earth’s surface from the past to the present and the present to the future for cloudless days is calculated in intervals of 1,000 years from 100000 years before present (BP) to 100000 years after present (AP), its basis being Milankovic’s theory. But the result are not the well-known Milankovic-curves, which are calculated for different latitudes and in which the x-axis represents years and the y-axis represents the insolation difference to present during the North-summer half-year. The calculations are made for each day of the selected years from the South Pole to the North Pole. Thus, two temporal dimensions are represented, that of a year and that of a day, furthermore the spatial dimension “latitude” and the dimension “energy” (insolation deviation). The performance of modern PCs allows the results of the calculations to be presented by a graphical animation. A determined deviation pattern of the insolation is obtained for each year. δ¹⁸O data, the mean global temperature and the additional ice volume on the continents are added to the graphic representations of those patterns for the period from 100000 years BP to the present. During that period insolation deviation patterns can be recognised which correlate with cool climates or climates getting cooler, and others which correlate with relatively warm climates or climates getting warmer. Correlations between the patterns are calculated and groups of similar patterns can be composed which can be associated in most cases with specific climatic conditions or specific climatic change. Comparison of patterns between 100000 years and present BP with patterns between present and 100000 years AP can help to estimate climatic change during the 100000 years ahead.  相似文献   

A new method in palaeoecology: fish community structure indicates environmental changes     

Ulrich Schmölcke  Kenneth Ritchie 《International Journal of Earth Sciences》2010,99(8):1763-1772

A new method to reconstruct aquatic palaeoenvironments is presented. It is based on a non-metrical ‘fish environment reconstruction index’ (FERI), calculated for the total fish community recorded at an archaeological site. As an example, a FERI is generated for the Baltic Sea using the ecological requirements of northern European fish species. The present study evaluates the proposed method by using fish bone assemblages from a region (the middle Holocene Baltic Sea coast) with well-studied hydrographic history. The bones originate from consecutive human riparian and coastal settlements of hunter-gatherers. The results obtained for the parameters salinity and sediment structure correlate well with geological knowledge. The new method shows a successive change from freshwater to brackish and finally to nearly marine conditions before, during, and towards the end of the marine transgression that created the present Baltic Sea. Additionally, a shift in the sediment structure from muddy to sandy/rocky conditions is recognisable.  相似文献   

Crater floor topography and impact melt sheet geometry of the Sudbury impact structure,Canada     

René Dreuse  Daniel Doman  Tasca Santimano  Ulrich Riller 《地学学报》2010,22(6):463-469

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Letter to the Editor: Comment on “Logratio Analysis and Compositional Distance” by J. Aitchison, C. Barceló-Vidal, J. A. Martín-Fernández, and V. Pawlowsky-Glahn     

Sönke Rehder  Ulrich Zier 《Mathematical Geology》2001,33(7):845-848

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Limnological description of the Lakes Zürich, Lucerne, and Cadagno     

Peter Bossard  Sonja Gammeter  Christine Lehmann  Ferdinand Schanz  Reinhard Bachofen  Hans-Rudolf Bürgi  Daniel Steiner  Ulrich Zimmermann 《Aquatic Sciences - Research Across Boundaries》2001,63(3):225-249

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Über das Vorkommen verschiedener Arten der GattungCyclops (s. restr.) in schweizerischen Seen     

Friedrich Kiefer  Ulrich Einsle 《Aquatic Sciences - Research Across Boundaries》1962,24(1):44-48

Ohne Zusammenfassung  相似文献   

Heavy metal accumulation in river sediments: A response to environmental pollutionSchwermetall-anreicherung in fluviatilen sedimenten als ausdruck der verschmutzung unserer umwelt     

Ulrich Förstner  German Müller 《Geoforum》1973,4(2):53-61

As evidenced by catastrophic cadmium and mercury poisonings in japan, heavy metals belong to the most toxic environmental pollutants. Through the investigation of sediments, the extent, distribution and provenance of heavy metal contamination in rivers and lakes can be determined and traced. Eight heavy metals from the clay fraction of sediments from major rivers within the Federal Republic of Germany were determined by means of atomic adsorption spectrometry. Heavy metals especially known for their high toxicity are enriched most: mercury, lead and zinc by a factor of 10; cadmium by a factor of 50, as compared with the natural background of these elements. A mobilisation of heavy metals from the suspended load and from the sediments, as to be observed in rivers approaching the marine enviromment, could endanger marine organisms, thus negatively influencing the acquatic food chain. With a further increase of heavy metal pollution, a threat to the drinking water supplied by rivers and lakes cannot be excluded.  相似文献   

Untersuchungen zur Morphologie des Schelfrandes vor Mozambique nordöstlich der Sambesi-Mündung     

Dr. Johannes Ulrich  Dr. Horst Pasenau 《Ocean Dynamics》1973,26(5):216-225

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Structural phase transition in titanite,CaTiSiO5: A ramanspectroscopic study     

Ekhard Salje  Claudia Schmidt  Ulrich Bismayer 《Physics and Chemistry of Minerals》1993,19(7):502-506

The structural phase transition in titanite is correlated with a strong temperature dependence of Raman scattering cross sections and, to a somewhat lesser extent, with shifts of the phonon frequencies. Their quantitative temperature evolution in the low-symmetry phase (P2₁/a) is compatible with a nearly 2D Ising behaviour with β≈0.12 and T _c = 497 K. At temperatures above 860 K, the phonon signals agree with A 2/a symmetry but not in the temperature interval between 497 K and 860 K. In this temperature range new structural states give rise to additional phonon signals. A model based on mobile APBs between slabs of P2₁/a material, first proposed by van Heurck et al. (1991), is in qualitative agreement with our experimental observations.  相似文献   

An experimental study of the titanomagnetite solid solution series     

Ulrich Bleil 《Pure and Applied Geophysics》1976,114(2):165-175

Summary Analysis of saturation magnetization measurements and data from the literature indicate that the cation distribution in the titanomagnetite solid solution series is temperature dependent. The ionic configuration of ferric and ferrous ions on both lattice sites of their spinel structure can be described by a modified Boltzmann relation in agreement with theoretical consideratios. Thermodynamic equilibrium isotherms for the cation distribution and the resulting variation of saturation magnetization are calculated on the basis of the experimental values. These results should be especially valuable for the interpretation of magnetic properties of rapidly cooled igneous rock units where a respective high-temperature metastable state may exist in the magnetic ore component.Further measurements of the Curie temperature and lattice constant did not confirm a similar effect. Both these parameters should therefore be qualified for the identification of naturally occurring titanomagnetites.  相似文献