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Published byHilda Jenkins Modified over 9 years ago
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Geomagnetism: Earth’s magnetic field Dipole Field
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Strength of Earth’s magnetic field (nT)
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Higher order poles
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Power spectrum of Earth’s magnetic field
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Inclination of Earth’s magnetic field
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Inclination and Declination Inclination is related to latitude Declination depends on horizontal components
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Declination of Earth’s magnetic field
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Magnetic North Pole vs. time
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Magnetic vs. Geographic coordinates Dipole drifts westward at: 0.044 - 0.14°/century (2500-8000 yr period) Non-dipole features drift westward at: 0.2 – 0.7°/century (550-1650 yr period)
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Geomagnetic field strength is decreasing: Will fall to zero in the year 4000: The beginning of a reversal?
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Paleomagnetism: Study of geomagnetic field vs. time Spinner magnetometer Astatic magnetometer Cryogenic magnetometer
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Axial Geocentric Dipole Hypothesis:average over 10 4 years is geographic pole tan I = 2 tan λ Plio-Pleistocene paleomag poles
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Calculating a paleomagnetic pole
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Baked contact test
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Reversals Test
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Apparent Polar Wander paths
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Paleo Reconstructions
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Magnetic Reversals
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Magnetic Reversals vs. Time
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