Results 151 to 160 of about 519 (182)
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Shape analysis of paleosecular variation data
Journal of Geophysical Research, 1974Shape analysis of paleosecular variation (PSV) data, if it is properly used, can determine the statistical character of a PSV data set in many cases. Existing statistical techniques, such as the χ2 goodness of fit test, the ‘dipole moment,’ and eigenvalue methods, are reviewed with this point in mind.
Czang-Go Baag, C. E. Helsley
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Anisotropic paleosecular variation models: implications for geomagnetic field observables
Physics of the Earth and Planetary Interiors, 1999Abstract We present a family of statistical models for paleosecular variation (PSV) of the geomagnetic field that are compatible with paleodirectional and paleointensity variations in lava flows sampling the last 5 Ma, and explore what paleomagnetic observables might be used to discriminate among the various family members. We distinguish statistical
C G Constable, Catherine L Johnson
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Paleosecular variation of field intensities and dipole moments
Earth and Planetary Science Letters, 1996Abstract In order to use paleointensity data for paleosecular variation studies, we first obtain analytical for the intensity of the geomagnetic field and the corresponding dipole moment in terms of Gauss coefficients. Next, statistical parameters for these quantities are derived under the assumption that Gauss coefficients vary randomly with time ...
Masaru Kono, Osamu Hiroi
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Model of geomagnetic paleosecular variations for the Northern Hemisphere
Studia Geophysica et Geodaetica, 1991A model of radial drifting and oscillating dipoles to represent geomagnetic palaeosecular variations, which showed to be appropriate for the Southern Hemisphere, is evaluated for the Northern Hemisphere. After a new fitting of some involved parameters, its theoretical results are compared with the palaeomagnetic data of Lake de Bouchet (France) and the
Ana M. Sinito, Juan F. Vilas
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Geomagnetic paleosecular variation in Easter Island, the southeast Pacific
Physics of the Earth and Planetary Interiors, 1998Abstract We collected more than 250 samples from 45 sites in lava flows of the three volcanoes on Easter Island. The K–Ar whole rock dating was attempted on 13 sites. All of the ages obtained are younger than 0.8 Ma. Reliable paleomagnetic directions were obtained from 34 sites.
Masako Miki +6 more
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Quantifying paleosecular variation: Insights from numerical dynamo simulations
Earth and Planetary Science Letters, 2013Abstract Thanks to advances in dynamo modelling, it is now possible to produce numerical sequences of magnetic polarity reversals over periods of time equivalent to several tens of millions of years. Using a set of five numerical models integrated over the equivalent of 40–50 Myr, we generated synthetic data analogous to paleomagnetic data derived ...
F Lhuillier, Stuart A Gilder
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Physics of the Earth and Planetary Interiors, 2011 : High-resolution paleo- and rock magnetic studies were performed on a group of four sediment cores from Laguna Potrok Aike (Santa Cruz, Argentina) representing the time period AD 1300-2000. The rock magnetic analyses show that the main magnetic mineral
Claudia S G Gogorza +2 more
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A 10,000 yr record of high-resolution Paleosecular Variation from a flowstone of Rio Martino Cave, Northwestern Alps, Italy [PDF]
Earth and Planetary Science Letters, 2018 Speleothems are potentially excellent archives of the Earth’s magnetic field, capable of recording its past variations. Their characteristics, such as the continuity of the record, the possibility to be easily dated, the almost instantaneous remanence ...
Elena Zanella +2 more
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A new method to determine paleosecular variation
Physics of the Earth and Planetary Interiors, 1994Abstract This study is based on synthetic virtual geomagnetic pole distributions simulated by the sum of a Fisherian distribution characteristic of paleosecular variation (PSV) and a uniform distribution representing transitional data resulting from reversals and excursions of the geomagnetic field. Using such simulations, the optimum cutoff angle to
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Paleosecular variation during sequential geomagnetic reversals from Hawaii
Earth and Planetary Science Letters, 1999Abstract Paleomagnetic directions measured from 175 flows in four volcanic sequences on the island of O'ahu (Hawaii) cover about 0.3 m.y. of geomagnetic field changes and include detailed records of the successive Gilbert-Gauss (3.57 Ma) and Lower Mammoth reversals (3.33 Ma).
Emilio Herrero-Bervera +1 more
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