Brunhes Epoch Geomagnetic Secular Variation on Marion Island: Contribution to Evidence for a Long-Term Regional Geomagnetic Secular Variation Maximum
A paleomagnetic study of 30 lavas from Marion Island, situated on the Indian-Atlantic ridge yields a value for Brunhes epoch secular variation with confidence limits so broad that no distinction can be made with present geomagnetic field behavior. When combined with similar results from the nearby C...
Published in: | Journal of geomagnetism and geoelectricity |
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1974
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ftlouisianastuir:oai:digitalcommons.lsu.edu:geo_pubs-1876 2023-06-11T04:11:12+02:00 Brunhes Epoch Geomagnetic Secular Variation on Marion Island: Contribution to Evidence for a Long-Term Regional Geomagnetic Secular Variation Maximum Amerigian, C. Watkins, N. D. Ellwood, B. B. 1974-01-01T08:00:00Z https://digitalcommons.lsu.edu/geo_pubs/877 https://doi.org/10.5636/jgg.26.429 unknown LSU Digital Commons https://digitalcommons.lsu.edu/geo_pubs/877 doi:10.5636/jgg.26.429 Faculty Publications text 1974 ftlouisianastuir https://doi.org/10.5636/jgg.26.429 2023-05-28T18:31:22Z A paleomagnetic study of 30 lavas from Marion Island, situated on the Indian-Atlantic ridge yields a value for Brunhes epoch secular variation with confidence limits so broad that no distinction can be made with present geomagnetic field behavior. When combined with similar results from the nearby Crozet Islands, however, data for over 100 separate lavas become available for analysis, facilitating an estimate of regional secular variation with narrow confidence limits. The result, which suggests that Brunhes epoch geomagnetic secular variation in this region was (at the 95 percent confidence level) higher than at present, could be explained if the present secular variation maximum south of South Africa persisted during at least the past half million years. It is concluded that values of Brunhes epoch geomagnetic secular variation may depend not only on latitude, experimental methods, and coverage of the geological interval involved, but also on proximity to long term isoporic foci. Incidental results for the survey include detection of excursions attributable to non-dipole behavior in some instances, and possible dipole tilting in other cases. © 1974, Society of Geomagnetism and Earth, Planetary and Space Sciences. All rights reserved. Text Crozet Islands Marion Island LSU Digital Commons (Louisiana State University) Indian Tilting ENVELOPE(-54.065,-54.065,49.700,49.700) Journal of geomagnetism and geoelectricity 26 4 429 441 |
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Open Polar |
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LSU Digital Commons (Louisiana State University) |
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ftlouisianastuir |
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description |
A paleomagnetic study of 30 lavas from Marion Island, situated on the Indian-Atlantic ridge yields a value for Brunhes epoch secular variation with confidence limits so broad that no distinction can be made with present geomagnetic field behavior. When combined with similar results from the nearby Crozet Islands, however, data for over 100 separate lavas become available for analysis, facilitating an estimate of regional secular variation with narrow confidence limits. The result, which suggests that Brunhes epoch geomagnetic secular variation in this region was (at the 95 percent confidence level) higher than at present, could be explained if the present secular variation maximum south of South Africa persisted during at least the past half million years. It is concluded that values of Brunhes epoch geomagnetic secular variation may depend not only on latitude, experimental methods, and coverage of the geological interval involved, but also on proximity to long term isoporic foci. Incidental results for the survey include detection of excursions attributable to non-dipole behavior in some instances, and possible dipole tilting in other cases. © 1974, Society of Geomagnetism and Earth, Planetary and Space Sciences. All rights reserved. |
format |
Text |
author |
Amerigian, C. Watkins, N. D. Ellwood, B. B. |
spellingShingle |
Amerigian, C. Watkins, N. D. Ellwood, B. B. Brunhes Epoch Geomagnetic Secular Variation on Marion Island: Contribution to Evidence for a Long-Term Regional Geomagnetic Secular Variation Maximum |
author_facet |
Amerigian, C. Watkins, N. D. Ellwood, B. B. |
author_sort |
Amerigian, C. |
title |
Brunhes Epoch Geomagnetic Secular Variation on Marion Island: Contribution to Evidence for a Long-Term Regional Geomagnetic Secular Variation Maximum |
title_short |
Brunhes Epoch Geomagnetic Secular Variation on Marion Island: Contribution to Evidence for a Long-Term Regional Geomagnetic Secular Variation Maximum |
title_full |
Brunhes Epoch Geomagnetic Secular Variation on Marion Island: Contribution to Evidence for a Long-Term Regional Geomagnetic Secular Variation Maximum |
title_fullStr |
Brunhes Epoch Geomagnetic Secular Variation on Marion Island: Contribution to Evidence for a Long-Term Regional Geomagnetic Secular Variation Maximum |
title_full_unstemmed |
Brunhes Epoch Geomagnetic Secular Variation on Marion Island: Contribution to Evidence for a Long-Term Regional Geomagnetic Secular Variation Maximum |
title_sort |
brunhes epoch geomagnetic secular variation on marion island: contribution to evidence for a long-term regional geomagnetic secular variation maximum |
publisher |
LSU Digital Commons |
publishDate |
1974 |
url |
https://digitalcommons.lsu.edu/geo_pubs/877 https://doi.org/10.5636/jgg.26.429 |
long_lat |
ENVELOPE(-54.065,-54.065,49.700,49.700) |
geographic |
Indian Tilting |
geographic_facet |
Indian Tilting |
genre |
Crozet Islands Marion Island |
genre_facet |
Crozet Islands Marion Island |
op_source |
Faculty Publications |
op_relation |
https://digitalcommons.lsu.edu/geo_pubs/877 doi:10.5636/jgg.26.429 |
op_doi |
https://doi.org/10.5636/jgg.26.429 |
container_title |
Journal of geomagnetism and geoelectricity |
container_volume |
26 |
container_issue |
4 |
container_start_page |
429 |
op_container_end_page |
441 |
_version_ |
1768386127847227392 |