Rapid climate change in the Upper Palaeolithic: the record of charcoal conifer rings from the Gravettian site of Dolní Vĕstonice,Czech Republic     

David Beresford-Jones  Sean Taylor  Clea Paine  Alexander Pryor  Jiří Svoboda  Martin Jones 《Quaternary Science Reviews》2011,30(15-16):1948-1964

Precisely how Upper Palaeolithic human ecology was shaped by changing climate during the Pleniglacial remains a matter of debate, for while this generally cold period is now understood to include complex and often rapid flux in climate, there are still considerable difficulties in resolving climatic variations at particular times and places — derived from various lines of proxy evidence — with the high-resolution proxy record of temperature changes from oxygen isotope analysis of the Greenland ice-cores.In this paper we apply the methodology of large-scale flotation to newly excavated contexts from the Upper Palaeolithic (Gravettian) site of Dolní V?stonice II, Czech Republic, to explore the potential of charcoal — as a natural archive of environmental information — to offer information on environmental change towards the end of the middle pleniglacial during Oxygen Isotope Stage 3, between c. 32,500 and 31,200 Cal yr BP. The results of an analysis of ring widths and other anatomical features — interpreted alongside micromorphological data — indicate that this charcoal may capture a higher-resolution record of the changing climatic conditions during which humans were first expanding into these hitherto marginal ecologies and, consequently, shed new light upon the complexity of the lifeways that enabled them to do so.  相似文献   

On some of the properties of the discrete model of turbulent diffusion     

Jiří Horák  Reviewer J. Navrátil 《Studia Geophysica et Geodaetica》1973,17(2):149-164

Zusammenfassung Den Prozess der Übertragung passiver Substanz im Felde der turbulenten Strömung untersuchen wir an einem Modell der zufälligen Bewegung. Es besteht eine enge Beziehung zwischen der geometrischen Struktur des gewählten stochastischen Modells und den Invarianten isomorpher Abbildungen, von denen die eine als ein Bewegungsgesetz der Evolution des Systems gilt und die zweite die sog. K-adische Abbildung darstellt. Diese Invarianten werden durch die Ergodizität des Systems, sein Durchmischen (die Durchmischungs-Eigenschaft) und durch die Entropie charakterisiert. Die Existenz des Durchmischungs bei der Bewegung des Systems bildet eine unerlässliche Bedingung für die Erklärung des Begriffes der Irreversibilität und des Relaxations-prozesses.

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Dedicated to 90th Birthday of Professor Frantiek Fiala  相似文献   

Station Correction of the seismic station Kašperské Hory for short-periodP waves     

Carmen Sobotová  Jiří Vaněk  Reviewer K. Pěč 《Studia Geophysica et Geodaetica》1973,17(3):260-261

Summary The magnitude station correction of the seismic station Kaperské Hory, related to Prhonice, was determined for the vertical component of short-period P waves.  相似文献   

Fitting the amplitude curves of seismic waves by numerical methods     

Karel Klíma  Jiří Vaněk 《Studia Geophysica et Geodaetica》1969,13(3):267-275

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Influence of geological factors on seismic ground-motions (seismic microzoning of Prague)     

Jiří Zahradník  Vlastislav Červený  Vladimír Barták  Reviewer V. Kárník 《Studia Geophysica et Geodaetica》1981,25(4):343-355

Summary Seismic microzoning of Prague was performed using geological data and seismic response (ground shaking) computations. The Prague territory was covered by a square grid, each square 250 m×250 m being characterized by a simplified geological cross-section from the Earth's surface to the bedrock boundary. The data were obtained from detailed engineering-geological maps 1:5000. The geological cross-sections were transformed into a set of layered models, specified by the thicknesses of individual layers and corresponding compressional and shear-wave velocities, densities and parameters of the causal absorption. The seismic responses were computed by the matrix method. The main amplitude and frequency characteristics of the responses are demonstrated in the form of microzoning maps. The maps do not depend on the specific type of seismic excitation. They make it possible to predict the relative amplification of P and S waves, with respect to the bedrock outcrop, all over the city.  相似文献   

Amplitude curves ofP waves for the region of central Asia     

Jiří Vaněk  Aleksander Tskhakaya  Reviewer J. Janský 《Studia Geophysica et Geodaetica》1977,21(3-4):259-267

Summary The amplitude-distance curves of P waves, valid for the region of Central Asia, were derived in the distance range between 13° and 36° using observations of a network of eight Caucasian seismic stations. The curves are characterized by an anomalous increase of amplitudes between 13° and 20° followed by a large decrease of amplitudes in the distance range between 20° and 35°. Both the increase and decrease of amplitudes are interrupted by several local maxima. A comparison of the present amplitude curves with those derived for the regions of South-Eastern Europe and Asia Minor enabled us to correlate the individual local maxima of amplitude curves and to investigate the variation of their position due to the lateral inhomogeneity of the upper mantle structure in Eurasia.A. Tskhakaya deceased in 1970.  相似文献   

Model of medium with cracks and its parameters obtained by observing longitudinal waves     

Jiří Jech  Reviewer V. Červený 《Studia Geophysica et Geodaetica》1983,27(4):366-371

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Distribution of radioactive elements in three progressively metamorphosed pelite series of the Bohemian Massif     

Jiří Fiala  Věra Vaňková  Milan Krešl  Werner Franke  Reviewer M. Chlupáčová  J. Losert 《Studia Geophysica et Geodaetica》1980,24(1):65-87

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Conditions of generation of a stationary dipole magnetic field     

Jiří Trešl  Reviewer G. Siráň 《Studia Geophysica et Geodaetica》1979,23(2):160-167

Summary With the aid of the selected spherical model the conditions of generation of a stationary magnetic dipole field in a fluid electrically conducting spherical region, bounded by an outer unconducting region, are derived. It is assumed that there exist turbulent motions in the conducting medium, as well as differential rotation. The induction MHD equation is solved under appropriate boundary conditions. It was found that a stationary dipole field may only be generated at a certain positive value of the coefficient G which characterizes the geometric and physical parameters of the conducting region. If this coefficient is zero, the amplitudes of the magnetic fields decrease exponentially with time.  相似文献   

Elastic properties of garnet solid-solution series     

Vladislav Babuška  Jiří Fiala  Mineo Kumazawa  Ichiro Ohno  Yoshio Sumino 《Physics of the Earth and Planetary Interiors》1978,16(2):157-176

The elastic constants of sixteen garnet specimens of wide variety in chemical composition are accurately determined by means of the rectangular parallelpiped resonance method. The dependence of the elastic properties on chemical composition is analyzed using the present data and those for seven garnets investigated by other authors. The property X_i of a garnet solid solution i is given by a linear addition law in terms of the mole fraction n_ij of component j; X_i = Σn_ijX_j where the X_j's are the properties of the end-members j (j = pyrope, almandine, spessartine, grossular and andradite). The X_j's are determined for density ρ, bulk modulus K, and shear moduli C_s = (C₁₁ ? C₁₂)/2 and C₄₄. No systematic deviation is observed from the linear addition law for the elastic moduli nor for other quantities such as the elastic wave velocities. The extrapolated elastic moduli (Mbar) of the end-members are: