Secular variation of the Late Archean–Early Proterozoic geodynamo
نویسندگان
چکیده
منابع مشابه
High-resolution record of geomagnetic secular variation from Late Pleistocene Lake Lisan sediments (paleo Dead Sea)
We measured geomagnetic secular variation in Lake Lisan sediments (paleo Dead Sea). More than 1500 oriented samples were collected from a 27.3-m section of alternating aragonite and detritus laminae in the Dead Sea basin ranging in age from 67 to 32 ka. The natural remanent magnetization (NRM) is carried by titanomagnetite in the detrital laminae whereas the aragonite is diamagnetic. The NRM is...
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A structural and petrological study of the Late Proterozoic rocks in the Wadi Kid area, Sinai, Egypt indicates the presence of an extensional metamorphic core complex in the northern Arabian–Nubian Shield. Gneissic domes throughout the Arabian–Nubian Shield resemble the core complex of the Wadi Kid area and as a result, they are interpreted as extensional metamorphic core complexes. The presenc...
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to reach sexual maturity [7] and is thus absent from its natal area for much longer than animals such as salmon and elephant seals [2,3]. Given this long absence, the Kemp’s ridley appears to be particularly susceptible to effects of secular variation if it relies on magnetic imprinting. The modeling results we report here show that the magnetic imprinting hypothesis can account for how the Kem...
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Knowledge of solar variability and its effects on the Earth is essential since the Sun affects almost every aspect of our lives. Direct observations of the Sun, usually of sunspots, with some continuity, exist only since about 1700. Understanding of long-term solar variability must then depend on proxy data, such as visual auroral observations, measurements of magnetic activity, and the radioca...
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Three-dimensional numerical simulations of convection and magnetic ®eld generation in the Earth’s core now span several hundred thousand years; the magnetic ®eld created during most of this time has an intensity, structure and time dependence similar to the present geomagnetic ®eld. Five models are described here. The ®rst is a homogeneous Boussinesq model, driven steadily by heat sources on th...
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ژورنال
عنوان ژورنال: Geophysical Research Letters
سال: 2004
ISSN: 0094-8276
DOI: 10.1029/2004gl020333