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2003-2004 USAP
Field Season
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Geology & Geophysics
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Dr. Rama K. Kotra
Program Manager
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G-182-M
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NSF/OPP
02-29403
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Station:
McMurdo Station
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RPSC POC:
Patricia Jackson
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Research Site(s):
Royal Society Range, Cape Crozier, Cape Bird, McMurdo Station
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Dates in Antarctica:
Early January to mid February
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Geomagnetic field as recorded in the Mount Erebus Volcanic Province: Key to field structure at high southern latitudes
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Photo not available.
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Deploying Team Members:
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Cathy Constable
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Jasper G. Konter
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Hubert Staudigel
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Lisa Tauxe
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Research Objectives:
We aim to use lava flows from the Mount Erebus Volcanic Province to study the magnetic field of the Earth over the past 5 million years in order to test models of its geomagnetic dynamo. Paleomagnetic data (directions of ancient geomagnetic fields obtained from rocks) play an important role in a variety of geophysical studies of the Earth, including plate tectonic reconstructions, magnetostratigraphy, and studies of the behavior of the ancient geomagnetic field (called paleogeomagnetism).
Over the past four decades, the key assumption in many studies has been that the average direction of the paleomagnetic field corresponds to one that would have been produced by a geocentric axial dipole (analogous to a bar magnet at the center of the Earth) and that paleoinclinations (the dip of magnetic directions from rocks) provide data of sufficient accuracy to enable them to be used in plate reconstructions. A recent reexamination of the fundamental data underlying models of the time-averaged field has shown that the most glaring deficiency in the existing database is a dearth of high-quality information, including paleointensity data, from high latitudes.
We will therefore undertake a sampling and laboratory program on suitable sites from the Mount Erebus Volcanic Province in order to produce the quality data from high southern latitudes that are essential to an enhanced understanding of the time-averaged field and its long-term variations.
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