Results 181 to 190 of about 6,743 (215)
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Geomagnetic secular variation in the Indian Ocean
Earth and Planetary Science Letters, 2003Abstract Annual repeat stations in Australia and in South Africa show that secular variation may change rapidly and over short geographical distances in the Indian Ocean area. Satellite models show large secular variations in the center of the Indian Ocean where there are few island geomagnetic observatories.
J.R. Heirtzler, K. Nazarova
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Archaeomagnetic investigations of geomagnetic secular variations
Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1982Bulgarian archaeomagnetic directions and intensities show a satisfactory agreement with those for Ukraine and Paris. Bauer plots of declination against inclination show both clockwise and anticlockwise looping through the last eight millennia. The necessity for accurate dating of samples studied is stressed.
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Varying geomagnetic anomalies and secular variation
Journal of Geophysical Research: Solid Earth, 1983The time variations of the geomagnetic field at 10 European observatories were examined in detail. Fourier analyses were made for three field components at each of the observatories. Curves for each component were synthesized for three passbands: A low passband for periods greater than 30 years, a mid passband for periods equal to or less than 30 years
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Some morphological aspects of geomagnetic secular variation
Planetary and Space Science, 1965Abstract Analysis of geomagnetic secular variation data, in the three elements X, Y and Z at five observatories distributed over the Earth, shows that amplitudes obtained for a 50 year cycle by harmonic analysis are highly significant. Amplitudes of higher order harmonics are found to be either not as significant or not significant, indeed, the cycle
L. Slaucitajs, D.E. Winch
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On the unpredictability of geomagnetic secular variation
Physics of the Earth and Planetary Interiors, 1985Abstract Various methods for the prediction of secular variation are tested by applying them to data for a single element at a single station. None of them is of any use for more than a few years.
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Historical Secular Variation and Geomagnetic Theory
1989The historical record of magnetic observations from AD 1695 has been analyzed to give maps of the magnetic field at the core-mantle boundary for the last 300 yr. These maps have been interpreted qualitatively in terms of a stationary dynamo field with hemispheric symmetry and a pattern of secular variation linked to the base of the solid mantle by ...
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Bottom-up control of geomagnetic secular variation by the Earth’s inner core
Nature, 2013Julien Aubert +2 more
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Geomagnetic polarity reversals: A connection with secular variation and core-mantle interaction?
Reviews of Geophysics, 1994David Gubbins
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The geomagnetic secular‐variation timescale in observations and numerical dynamo models
Geophysical Research Letters, 2011Florian Jl Lhuillier +2 more
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