Results 251 to 260 of about 174,256 (296)

Secular Variation in Scandinavia

Nature Physical Science, 1971
This article discusses the considerable differences between the variations of the geomagnetic field given by the International Geomagnetic Reference Field at locations in Scandinavia and the variations derived from data obtained at Scandinavian observatories. The reasons for the discrepancies remain obscure.
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Dynamics of the secular variation

Physics of the Earth and Planetary Interiors, 1991
Abstract There have been many calculations of core motions from secular variation data using the induction equation in the frozen-flux approximation. The induction equation does not allow unique flows to be determined and additional constraints are required.
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The analysis of the geomagnetic secular variation

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1951
Abstract After some discussion of the general properties of the secular variation field, a graphical method is described of analyzing it in terms of separate dipoles of arbitrary direction. The analysis shows that the major part of the field for epoch 1922.5 is explained by about twelve vertical dipoles below the surface of the core ...
F. J. Lowes, S. J. Runcorn
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Secular Gravity Variations

1993
Detailed analysis of repeated absolute gravity determinations that have been carried out during last 15 years using ballistic gravimeters at stations located in Europe (Potsdam, Sevres), and Northern America (Denver) permits to suspect the existence of global gravity variations with amplitudes of about 30–40 microgal which seem to be correlated with ...
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Secular Variation in Economic Geology

Economic Geology, 2010
The temporal pattern of ore deposits on a constantly evolving Earth reflects the complex interplay between the evolving global tectonic regime, episodic mantle plume events, overall changes in global heat flow, atmospheric and oceanic redox states, and even singular impact and glaciation events. Within this framework, a particular ore deposit type will
R. J. Goldfarb, D. Bradley, D. L. Leach
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Secular variation magnetostratigraphy

1986
This chapter concentrates on secular variation magnetostratigraphic dating applications within the past 10 000 years. It describes collection and measurement techniques which have been found useful in investigating lake sediments and presents type palaeomagnetic secular variation records of both declination and inclination, from seven regions of the ...
Roy Thompson, Frank Oldfield
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III. On a secular variation in the rainfall in connexion with the secular variation in amount of sun-spots

Proceedings of the Royal Society of London, 1876
Abstract In this paper the author sums up the principal results obtained by his Investigations as follows:— (1.) Taking for the individual years of maximum and minimum sunspot those given in par. 4, it is found that the rainfall in the maxima exceeds the rainfall in the minima years in each country or district, and therefore in all ...
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Geomagnetic secular variations and surveys

Proceedings of the Physical Society, 1946
The secular variations of the Earth's field call for frequent determinations of the geomagnetic elements at many selected stations on land and at sea. So far, general world magnetic surveys have of necessity been restricted to the surface of the Earth.
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secular variation

2014
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