Geomagnetic field from the Earth's core: Its westward drift rate and some probable global-tectonics implications

Summary Sets of virtual poles corresponding to sets of geomagnetic field values at equidistant points, lying along circles of latitude, were defined on the basis of the 1980 IGRF extending to degree and order 8. Certain places on the Earth's surface yield virtual poles lying very close together. The segments of the virtual pole paths, corresponding to these places, have a large curvature. The mentioned places of the Earth's surface are supposed to be areas with a low rate of the westward drift. They form continuous zones that show a certain relation to global-tectonics features.

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uum ¶rt; 8- n¶rt;a ¶rt;a¶rt; aaumu n 1980 u u nmu uma n, mmmu nm uu n ma, a u¶rt;umam ¶rt; naa m ma nmu nua¶rt;am uma n, m uu ¶rt; ¶rt;. amu u, mmmu mu ma, um uu. ¶rt;naam, m nm ma nmu m amu, m m ana¶rt; ¶rt;a ua. u am n na, m naam a m uua mmuu.

     

Statistical analysis of values measured in condensating geodetic nets

Summary Procedure for verifying the agreement between parameters common to the basic and connecting trigonometric net. Procedure of determining the accuracy of the connecting net. This determination concerns not only the relativized accuracy of the points of the connecting network, but also the mutual accuracy of the points of the basic net relative to the points of the connecting net and the global accuracy of the resultant net. The procedure takes into account the accuracy of the points of the basic net which remain unchanged in computing the coordinates of new points.

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m¶rt; ¶rt; nu au u naam¶rt;mu u nu¶rt;u m. m¶rt; ¶rt; u mmu nu¶rt;u mu. a aam m mum nua mmu m nu¶rt; mu, ma au mmu m mu n mu ma nu¶rt;u mu ua mmu mu mu. m¶rt; umam mm m mu, m aa uu ¶rt;uam m mam uu.

     

The Barents Sea Ice Sheet — A model of its growth and decay during the last ice maximum

On the basis of geomorphological and sedimentological data, we believe that the entire Barents Sea was covered by grounded ice during the last glacial maximum. ¹⁴C dates on shells embedded in tills suggest marine conditions in the Barents Sea as late as 22 ka BP; and models of the deglaciation history based on uplift data from the northern Norwegian coast suggest that significant parts of the Barents Sea Ice Sheet calved off as early as 15 ka BP. The growth of the ice sheet is related to glacioeustatic fall and the exposure of shallow banks in the central Barents Sea, where ice caps may develop and expand to finally coalesce with the expanding ice masses from Svalbard and Fennoscandia.The outlined model for growth and decay of the Barents Sea Ice Sheet suggests a system which developed and existed under periods of maximum climatic deterioration, and where its growth and decay were strongly related to the fall and rise of sea level.     

Trends in planetary wave activity in the upper middle atmosphere inferred from the nighttime LF radio wave absorption measurements

Summary The nighttime LF radio wave absorption in the lower ionosphere measured at two frequencies in central Europe over 1963–1985 is used to infer planetary wave activity and its long-term trend in the upper middle atmosphere (∼90–100 km). The observed positive trend is roughly consistent with results based on daytime absorption. Nighttime results are less pronounced and less statistically significant probably due to perturbing effects of geomagnetic activity. The observed trends, which are probably of anthropogenic origin, are together with the daytime results [3,4] the first evidence of long-term trends in planetary wave activity in the upper middle atmosphere.     

The photoelectron spectra of some Tl-Sb sulphosalts

The results of X-ray induced photoelectron spectroscopy (XPS) experiments on several phases of the ternary system Tl-Sb-S are reported. The binding energies of the inner S, Sb and Tl electrons increase with increasing quantities of Sb and decreasing amounts of Tl in these compounds. This is explained by the influences of the proportions of the bonded metals on the effective electron affinity of S. The higher proportions of the more electronegative element bonded to S cause the increase of its effective electron affinity. The results for Tl₂S (carlinite), Tl₃SbS₃, TlSbS₂ (weissbergite), TlAsS₂ (lorandite) and Sb₂S₃ (antimonite) can be interpreted in this way. The results for Tl₄S₃ suggest a predominantly covalent character of bonding for both Tl(III) and Tl(I), which are present in this sulfide. From comparison with Tl₃SbS₄ it could be supposed that Tl(III)-S bond has a more covalent character than Sb(V)-S bond. The results for Tl₃SbS₄ are in agreement with crystal structure data and the results of Moessbauer spectroscopy. For AsS (realgar) the binding energies of the inner electrons of As and S significantly increase, showing that the electrons in molecular orbitals are less strongly bonded to individual atoms, as compared to pure elements. The results for the amorphous TlSb₅S₈ (corresponding in composition to parapierrotite) suggest that in amorphous compound the Tl-S bonding is stronger and the coordination of Tl more regular than in a crystalline one.     

Modelling magnetization processes in single-and multi-domain rock samples using the preisach diagram

Summary The paper presents the results of identifying a model of the Preisach type for haematite grains of the single-domain as well as multi-domain size. Due to the phenomenological conception of the model, the relations between the parameters of the model and actual parameters are very complex, however, impressive accuracy and stability of the modified model indicate the need to resume studies of this problem. The model parameters also confirm the adequate properties of the vibrating-sample magnetometr (VSM) used and developed in our laboratories.     

Radioactive and trace element distribution in basaltic rocks of Lower Silesia

Summary The distribution of radioactive(Th, U, K) and selected trace(Rb, Sr, Ba, Y, Zr, V, Cr, Ni) elements in volcanic rocks from the Opole and Jawor regions of the Lower Silesia has been studied. The behaviour of these elements in the studied rocks indicates that the Lower Silesian volcanic rocks are characterized by less differentiated type than other volcanic rocks of the Bohemian Massif, the Opole rock types probably having a less differentiated character than the Jawor rock types.

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¶rt;a an¶rt;u a¶rt;uamu(Th, U, K) u m ¶rt;u(Rb, Sr, Ba, Y, Zr, V, Cr, Ni) m auu n¶rt;a am n u u uuu. a n mam n¶rt;num, m aum u uuu n¶rt;mam ¶rt; aamuu n¶rt; u ¶rt;uuau, aum u ana¶rt; uu. au a n¶rt;num, m auu n¶rt; amu n ¶rt;uuau ma ua n¶rt; u amu .

     

Expansions of the double product of the global gravity field

Summary Four fundamental forms of expansion of the double product of the gravity function into an infinite series are derived. Two isotropic parts are separated, one is expressed by Legendre polynomials and the other by invariants of Wigner's D-matrices.

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¶rt; m n¶rt;mau ¶rt; au ¶rt; nu¶rt;uaumau uu ¶rt;. ¶rt; ¶rt; umn amu, na aam n nu a¶rt;a u ma n uauam amu ua.