Dynamic manifestations of the geomagnetic field in the Quaternary continental sediments of Czechoslovakia     

Václav Bucha  Josef Horáček  Reviewer A. Janáčková 《Studia Geophysica et Geodaetica》1973,17(4):321-336

Summary The paper brings a brief geological asessment of the sedimentational cycles, analyses the methods of collection and investigation of samples and the representativeness of the results obtained. Problems of magnetic cleaning and the types of demagnetization curves investigated are discussed. The continuous nature of the variations of the magnetic declination, inclination and remanent magnetization, determined by palaeomagnetic investigation of Quaternary sediments, is also discussed. The conclusion contains the principal facts about the dynamics of the geomagnetic field in the Quaternary and points out the possibility of applying them to the theory of the geomagnetic field, as well as to geological correlations.  相似文献   

The Effect of Geomagnetic and Solar Activity on the Distribution of Controlling Pressure Formations in the Northern Hemisphere in Winter     

Bochníček  Josef  Hejda  Pavel  Pýcha  Josef 《Studia Geophysica et Geodaetica》1999,43(4):390-398

The distribution of controlling pressure formations, occurring in the Northern Hemisphere during the winters (January and February) of the years 1952 – 1996, has been analysed. It was found that the deepening of the Icelandic and Aleutian pressure lows is connected not only with a particular QBO phase and level of geomagnetic activity (Bochníek et al., 1999) but also with a particular level of solar activity.  相似文献   

Approximate spectral analysis by least-squares fit   总被引：4，自引：0，他引：4  

Petr Vaníček 《Astrophysics and Space Science》1969,4(4):387-391

An approximate method of spectral analysis called successive spectral analysis based upon the mean-quadratic approximation of an empirical function by generalised trigonometric polynomial with both unknown frequencies and coefficients is developed. A few quotations describing some properties of the method as well as one of the possible methods for numerical solution are given.  相似文献   

Climate in the Czech Lands during the 1780s in Light of the Daily Weather Records of Parson Karel Bernard Hein of Hodonice (Southwestern Moravia): Comparison of Documentary and Instrumental Data   总被引：1，自引：1，他引：0  

Rudolf Brázdil  Hubert Valášek  Jarmila Macková 《Climatic change》2003,60(3):297-327

  相似文献   

On the Integrability of Limited-Area Numerical Weather Prediction Model ALADIN over Extended Time Periods     

Huth  Radan  Mládek  Richard  Metelka  Ladislav  Sedlák  Pavel  Huthová  Zuzana  Kliegrová  Stanislava  Kyselý  Jan  Pokorná  Lucie  Halenka  Tomáš  Janoušek  Martin 《Studia Geophysica et Geodaetica》2003,47(4):863-873

This note summarizes results of the first integration of regional numerical weather prediction model ALADIN in a climate mode. The ALADIN model, developed in an international cooperation led by Météo France, is operationally used for weather prediction. The grid step of the model is 12 km; the integration domain covers a major part of Europe. A one-month-long run has been performed with this model on observed boundary conditions (represented by assimilations by the global model ARPEGE). It is demonstrated that no excessive error is generated and accumulated in the model during the integration; hence the model is integrable for extended time periods and may serve a basis for a development towards a regional climate model.  相似文献   

Geochemistry and mineralogy of Platinum-group elements in the Ransko gabbro–peridotite massif,Bohemian Massif (Czech Republic)     

Jan?Pa?avaEmail author  Ivan?Vav?ín  Ji?í?Fryda  Vojtěch?Janou?ek  Emil?Jelínek 《Mineralium Deposita》2003,38(3):298-311

The Ransko gabbro-peridotite massif in Eastern Bohemia is a strongly differentiated intrusive complex of Lower Cambrian age. The complex hosts low grade Ni-Cu ores mainly developed close to the contact of olivine-rich rocks with gabbros, in troctolites and, to a much lesser extent, in both pyroxene and olivine gabbros and plagioclase-rich peridotites. The ore zone is characterized by strong serpentinization and uralitization. The total Ni + Cu locally reaches up to 4 wt%. Anomalous concentrations of platinum-group elements (PGE's) (maximum 532 ppb Pd, 182 ppb Pt, 53 ppb Rh, 15 ppb Ru, 41 ppb Ir) were detected in samples of Cu-Ni and Ni-Cu ores (maximum 2.63 wt% Ni and 2.31 wt% Cu) from the Jezírka orebody. The main ore paragenesis includes pyrrhotite, pentlandite, chalcopyrite, cubanite, pyrite, magnetite, mackinawite, valleriite, ilmenite and sphalerite. During this work, michenerite, froodite, sperrylite, gold, native bismuth, altaite, tsumoite, hessite, an unnamed Bi-Ni telluride, cobaltite-gersdorffite and galena were newly identified. The host rocks originated through partial melting of a slightly depleted mantle source with noble metals scavenged from this primitive magma prior to the development of these rocks.  相似文献   

Monitoring of fault healing after the 1999 Kocaeli, Turkey, earthquake     

Keiichi Tadokoro  Masataka Ando  Şerif Bariş  Kin'ya Nishigami  Mamoru Nakamura  S. Balamir Ücer  Akihiko Ito  Yoshimori Honkura  A. Mete Işikara 《Journal of Seismology》2002,6(3):411-417

The North Anatolian fault zone that ruptured during the mainshock of theM 7.4 Kocaeli (Izmit) earthquake of 17 August 1999 has beenmonitored using S wave splitting, in order to test a hypothesisproposed by Tadokoro et al. (1999). This idea is based on the observationof the M 7.2 1995 Hyogo-ken Nanbu (Kobe) earthquake, Japan.After the Hyogo-ken Nanbu earthquake, a temporal change was detectedin the direction of faster shear wave polarization in 2–3 years after the mainshock (Tadokoro, 1999). Four seismic stations were installed within andnear the fault zone at Kizanlik where the fault offset was 1.5 m, about80 km to the east of the epicenter of the Kocaeli earthquake. Theobservation period was from August 30 to October 27, 1999. Preliminaryresult shows that the average directions of faster shear wave polarization attwo stations were roughly parallel to the fault strike. We expect that thedirection of faster shear wave polarization will change to the same directionas the regional tectonic stress reflecting fault healing process. We havealready carried out a repeated aftershock observation at the same site in2000 for monitoring the fault healing process.  相似文献   

Pre‐ and post‐test mathematical modelling of a plan‐asymmetric reinforced concrete frame building     

Peter Fajfar  Matja Dol&#x;ek  Damjan Maru&#x;i&#x;  Aurel Stratan 《地震工程与结构动力学》2006,35(11):1359-1379

Pre‐ and post‐test analyses of the structural response of a three‐storey asymmetric reinforced concrete frame building were performed, aimed at supporting test preparation and performance as well as studying mathematical modelling. The building was designed for gravity loads only. Full‐scale pseudo‐dynamic tests were performed in the ELSA laboratory in Ispra. In the paper the results of initial parametric studies, of the blind pre‐test predictions, and of the post‐test analysis are summarized. In all studies a simple mathematical model, with one‐component member models with concentrated plasticity was employed. The pre‐test analyses were performed using the CANNY program. After the test results became available, the mathematical model was improved using an approach based on a displacement‐controlled analysis. Basically, the same mathematical model was used as in pre‐test analyses, except that the values of some of the parameters were changed. The OpenSees program was employed. Fair agreement between the test and numerical results was obtained. The results prove that relatively simple mathematical models are able to adequately simulate the detailed seismic response of reinforced concrete frame structures to a known ground motion, provided that the input parameters are properly determined. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

The relation between rigorous and Helmert’s definitions of orthometric heights     

M. C. Santos  P. Vaníček  W. E. Featherstone  R. Kingdon  A. Ellmann  B. -A. Martin  M. Kuhn  R. Tenzer 《Journal of Geodesy》2006,80(12):691-704

Following our earlier definition of the rigorous orthometric height [J Geod 79(1-3):82–92 (2005)] we present the derivation and calculation of the differences between this and the Helmert orthometric height, which is embedded in the vertical datums used in numerous countries. By way of comparison, we also consider Mader and Niethammer’s refinements to the Helmert orthometric height. For a profile across the Canadian Rocky Mountains (maximum height of ~2,800 m), the rigorous correction to Helmert’s height reaches ~13 cm, whereas the Mader and Niethammer corrections only reach ~3 cm. The discrepancy is due mostly to the rigorous correction’s consideration of the geoid-generated gravity disturbance. We also point out that several of the terms derived here are the same as those used in regional gravimetric geoid models, thus simplifying their implementation. This will enable those who currently use Helmert orthometric heights to upgrade them to a more rigorous height system based on the Earth’s gravity field and one that is more compatible with a regional geoid model.  相似文献   

Long-term changes (1980–2003) in total ozone time series over Northern Hemisphere midlatitudes     

Małgorzata Białek 《Acta Geophysica》2006,54(1):60-70

Long-term changes in total ozone time series for Arosa, Belsk, Boulder and Sapporo stations are examined. For each station we analyze time series of the following statistical characteristics of the distribution of daily ozone data: seasonal mean, standard deviation, maximum and minimum of total daily ozone values for all seasons. The iterative statistical model is proposed to estimate trends and long-term changes in the statistical distribution of the daily total ozone data. The trends are calculated for the period 1980–2003. We observe lessening of negative trends in the seasonal means as compared to those calculated by WMO for 1980–2000. We discuss a possibility of a change of the distribution shape of ozone daily data using the Kolmogorov-Smirnov test and comparing trend values in the seasonal mean, standard deviation, maximum and minimum time series for the selected stations and seasons. The distribution shift toward lower values without a change in the distribution shape is suggested with the following exceptions: the spreading of the distribution toward lower values for Belsk during winter and no decisive result for Sapporo and Boulder in summer.  相似文献