Seismicity of Europe     

Vít Kárník 《Studia Geophysica et Geodaetica》1971,15(2):199-203

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Earthquake swarm in the region of Kraslice in 1962     

Vít Kárník 《Studia Geophysica et Geodaetica》1963,7(3):288-296

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The singularities in quantum cosmology     

A. M. Finkelstein  V. YA. Kreînovich 《Astrophysics and Space Science》1987,137(1):73-76

A cosmological model is proposed, in which quantum effects lead to infinitely many terms nonlinear in curvature, and these terms lead to the following conclusion: the physical singularity (i.e., a state with infinite matter densityp) occurs int10^–43 s, when the curvature is finite. An attempt is made to give physical interpretation of this model from the viewpoint of the foam-like model of space-time.  相似文献   

Long-term changes of the surface air temperature in relation to solar inertial motion   总被引：1，自引：0，他引：1  

Ivanka Charvátová  Jaroslav Střeštík 《Climatic change》1995,29(3):333-352

The inertial motion of the Sun around the barycentre, or centre of mass, of the Solar System has been employed as the base in searching for possible influence of the Solar System as a whole on climatic processes, especially on the changes in surface air temperature. A basic cycle of about 180–200 years and its higher harmonics up to 30 years have been found in surface air temperature of central Europe since 1753, established from 13 continuous instrumental time series. These periods correspond to the periods of solar inertial motion. In the first half of the 19th century, when the solar motion was chaotic, this temperature was about 0.75°C lower than that in the 20th (1940–50) and the 18th (1760–70) centuries. The mentioned decades of long-term temperature maxima coincide with the central decades of the ordered (trefoil) motion of the Sun. The temperatures in coastal Europe have been found to have slightly different properties, especially on a long-time scale. The periods of 35–45 years are significantly pronounced in the coastal Europe temperature spectrum. The chaotic motion of the Sun in the next decades could decrease both the solar forcing and global surface air temperature.This research was performed with support of the Grant Agency of the Czech Republic, Grant No. 205/93/0417, I. Charvátová: Prognosis of climate development in central Europe.  相似文献   

Significance of High-Frequency Wind Forcing in Modelling the Kuroshio   总被引：1，自引：0，他引：1  

Takuji?WasedaEmail author  Humio?Mitsudera  Bunmei?Taguchi  Kunio?Kutsuwada 《Journal of Oceanography》2005,61(3):539-548

Motivated by an analysis of a satellite sea surface temperature image suggesting that a train of extra-tropical cyclones induces amplification of the Kuroshio meander, a regional Kuroshio/Oyashio general circulation model was used to investigate the impact of high-frequency wind on the Kuroshio path variations. Near Japan, the standard deviation of the wind stress curl can be 10 times larger than the monthly mean, so the synoptic variations of the wind stress curl cannot be neglected. With the bimodal Kuroshio case realized in the model, sensitivity tests were conducted using monthly and daily mean QuikSCAT-derived wind stress forcings. The comparison showed that the high-frequency local wind perturbed the Shikoku recirculation gyre (SRG) and caused a transition of the path from straight to meander. The strong anticyclonic eddy within the SRG triggered the meander in the latter case. The high-frequency wind perturbed the motion of the eddy that would have otherwise detached from the Kuroshio, migrated south and terminated the meandering state. The result reinforces the suggestion from previous studies that the anticyclonic eddy within the SRG plays an active role in controlling the Kuroshio path variations.  相似文献   

Reproduction in two deep-sea anemones (Actiniaria); Phelliactis hertwigi and P. robusta     

M. van Praët  A.L. Rice  M.H. Thurston 《Progress in Oceanography》1990,24(1-4)

Bathymetric distribution, abundance, substrate choice and gametogenesis have been investigated in two species of deep-sea actiniarians found in the northeast Atlantic Ocean. Phelliactis hertwigi occurs at 719–1448m in the Porcupine Seabight, usually encloses a bolus of sediment within its highly concave pedal disc (79.7%), and has abundances of up to 14.5 individuals 1000m⁻². Phelliactis robusta occurs at 1600–2173m in the Porcupine Seabight, but extends deeper in the Bay of Biscay. In areas of soft sediment it is associated strongly with clinker (92.7%) and attains densities of 2.9 individuals 1000m⁻².Both species are dioecious. Their sperm appear similar to those of the related intertidal Calliactis spp. Previtellogenesis and vitellogenesis of the oocytes have been defined by ultrastructural and histochemical studies. In P. hertwigi mature oocytes measure up to 180μm, and to 210μm in P. robusta. In P. hertwigi oogenesis takes 8–9 months, with spawning in October/November, whereas in the deeper-living P. robusta oogenesis occupies 15 to 19 months and spawning occurs in April/ May. Evidence is produced to suggest that these two contrasting cycles are related to the rate and seasonality of deposition of organic matter to the deep-sea floor.  相似文献   

Amplitude-distance curves of surface waves at short epicentral distances (Δ<2000 km)     

Vít Kárník 《Studia Geophysica et Geodaetica》1962,6(4):340-346

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Geomorphological research of large-scale slope instability at Machu Picchu, Peru     

Vít Vilímek  Ji&#x;í Zvelebil  Jan Klime&#x;  Zdenk Patzelt  Fernando Astete  Vclav Kachlík  Filip Hartvich 《Geomorphology》2007,89(3-4):241-257

A multidisciplinary approach has been adopted to study the slope movements and landscape evolution at the archaeological site of Machu Picchu and its immediate surroundings. The basic event in the paleogeomorphological evolution of the area was the large-scale slope movement, which destroyed the originally higher ridge between Mt. Machupicchu and Mt. Huaynapicchu. Within remnants of that primary deformation, several younger generations of slope movements occurred. The laboratory analyses of granitoids revealed highly-strained zones on the slopes of Mt. Machupicchu, which strongly affect the largest slope deformation. The borders of the largest slope deformation are structurally predisposed by the existence of fault zones. The majority of various types of slope movements on the so-called Front Slope (E facing) and Back Slope (W facing) are influenced by the alignment between topography and joints. Along with slope movements, fluvial erosion and tectonic disturbance of the rocks have been affecting the evolution of the landscape. A monitoring network for dilatometric and extensometric measurements was used to detect the present-day activity of rock displacements within the archaeological site. In addition to standard mapping of surface hydrogeological phenomena, eleven express slug tests were conducted to verify the infiltration potential of precipitation. The results of these surveys indicate that recent large-scale slope movement as suggested by some previous studies is doubtful, and the detected movements can be explained by individual movements of rock blocks or several other mechanisms including sinking of archaeological structures, subsurface erosion and annual changes in the water content of the soils.  相似文献   

First results of DORIS data analysis at Geodetic Observatory Pecný     

Petr Štěpánek  Urs Hugentobler  Karine Le Bail 《Journal of Geodesy》2006,80(8-11):657-664

In a cooperation between the Astronomical Institute, University of Bern (AIUB), the Geodetic Observatory Pecný (GOPE), and the Institut Géographique National (IGN), DORIS data analysis capabilities were implemented into a development version of the Bernese GPS software. The DORIS Doppler observables are reformulated such that they are similar to global navigation satellite system (GNSS) carrier-phase observations, allowing the use of the same observation models and algorithms as for GNSS carrier-phase data analysis with only minor software modifications. As such, the same algorithms may be used to process DORIS carrier-phase observations. First results from the analysis of 3 weeks of DORIS data (September 2004, five DORIS-equipped satellites) at GOPE are promising and are presented here. They include the comparison of station coordinates with coordinate estimates derived by the Laboratoire d’Etudes en Géophysique et Océanographie Spatiale/Collecte Localisation Satellites analysis centre (LCA) and the Institut Géographique National/Jet Propulsion Laboratory (IGN/JPL), and the comparison of Earth orientation parameters (EOPs) with the International Earth Rotation and Reference Frames Service (IERS) C04 model. The modified Bernese results are of a slightly lower, but comparable, quality than corresponding solutions routinely computed within the IDS (International DORIS Service). The weekly coordinate repeatability RMS is of the order of 2–3 cm for each 3D station coordinate. Comparison with corresponding estimates of station coordinates from current IDS analysis centers demonstrates similar precision. Daily pole component estimates show a mean difference from IERS-C04 of 0.6  mas in X _p and  ? 0.5  mas in Y _p and a RMS of 0.8  mas in X _p and 0.9  mas in Y _p (mean removed). An automatic analysis procedure is under development at GOPE, and routine DORIS data processing will be implemented in the near future.  相似文献   

Grain size dependency in the occurrence of sand waves     

Hennie Henriët van der Veen  Suzanne Jacqueline Marie Hélène Hulscher  Michiel Adrianus Frederik Knaapen 《Ocean Dynamics》2006,56(3-4):228-234

Sandy shallow seas, like the North Sea, are very dynamic. Several morphological features are present on the bed, from small ripples to sand waves and large tidal sandbanks. The larger patterns induce significant depth variations that have an impact on human activities taking place in this area. Therefore, it is important to know where these large-scale features occur, what their natural behaviour is and how they interact with human activities. Here, we extend earlier research that compares the results of an idealized model of large-scale seabed patterns with data of seabed patterns in the North Sea. The idealized model is extended with a grain size dependency. The adaptations lead to more accurate predictions of the occurrence of large-scale bed forms in the North Sea. Therefore, grain size dependency and, in particular, critical shear stress are important to explain the occurrence of sand waves and sandbanks in the North Sea. Responsible Editor: Alejandro Souza  相似文献