Tests of inter-hotspot motion and of hotspot motion relative to the spin axis
First, an updated Pacific paleomagnetic skewness pole for chron 32 (72 Ma) is presented. The updated paleomagnetic pole corrects for the spreading-rate dependence of anomalous skewness, a correction which hasn't been applied to Pacific skewness poles before. The presence of anomalous skewness i...
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ftriceuniv:oai:scholarship.rice.edu:1911/62159 2023-05-15T13:34:53+02:00 Tests of inter-hotspot motion and of hotspot motion relative to the spin axis Koivisto, Emilia Anna-Liisa Gordon, Richard G. 2010 application/pdf https://hdl.handle.net/1911/62159 eng eng Koivisto, Emilia Anna-Liisa. "Tests of inter-hotspot motion and of hotspot motion relative to the spin axis." (2010) Diss., Rice University. https://hdl.handle.net/1911/62159 . https://hdl.handle.net/1911/62159 THESIS GEOL. 2010 KOIVISTO Geophysics Plate tectonics Thesis Text 2010 ftriceuniv 2022-08-09T20:51:16Z First, an updated Pacific paleomagnetic skewness pole for chron 32 (72 Ma) is presented. The updated paleomagnetic pole corrects for the spreading-rate dependence of anomalous skewness, a correction which hasn't been applied to Pacific skewness poles before. The presence of anomalous skewness is one of the main factors limiting the accuracy of paleomagnetic poles determined from the skewness data. Thus, successfully correcting for the anomalous skewness, as was done in this study, significantly improves the reliability of the skewness poles. The earlier assertions that the Hawaiian hotspot has shifted southward relative to the spin axis by 13° since ≈72 Ma are also confirmed. Second, updated reconstructions of the Pacific plate relative to the hotspots for the past 68 million years are presented, with the uncertainties in the reconstructions. Plate-circuit reconstructions are used to predict the tracks of some major Indo-Atlantic hotspots (Tristan da Cunha, Reunion and Iceland) from the Pacific-hotspot plate motion and the rates of relative motion between the Pacific and Indo-Atlantic hotspots are estimated. Within the uncertainties, motion between the hotspots is found insignificant for the past 48 million years. For earlier times, a systematic error in the plate circuit used to make the predictions is inferred and which may be due to unmodeled motion between East and West Antarctica. If the observed discrepancy can be shown to correspond to an error in the plate circuit, the southward motion of the Hawaiian hotspot of 13° since ≈72 Ma can likely be attributed to true polar wander. Building on the above-mentioned work, finally, for the first time, a globally self-consistent model of plate motions relative to the global hotspots for the past 48 million years is presented, and the implications of this model to the question of relative hotspot motion discussed. The provided globally self-consistent set of reconstructions can be used as a fixed frame of reference for absolute plate motions, and true polar wander, ... Thesis Antarc* Antarctica Iceland West Antarctica Rice University: Digital Scholarship Archive Pacific Tristan ENVELOPE(140.900,140.900,-66.735,-66.735) West Antarctica |
institution |
Open Polar |
collection |
Rice University: Digital Scholarship Archive |
op_collection_id |
ftriceuniv |
language |
English |
topic |
Geophysics Plate tectonics |
spellingShingle |
Geophysics Plate tectonics Koivisto, Emilia Anna-Liisa Tests of inter-hotspot motion and of hotspot motion relative to the spin axis |
topic_facet |
Geophysics Plate tectonics |
description |
First, an updated Pacific paleomagnetic skewness pole for chron 32 (72 Ma) is presented. The updated paleomagnetic pole corrects for the spreading-rate dependence of anomalous skewness, a correction which hasn't been applied to Pacific skewness poles before. The presence of anomalous skewness is one of the main factors limiting the accuracy of paleomagnetic poles determined from the skewness data. Thus, successfully correcting for the anomalous skewness, as was done in this study, significantly improves the reliability of the skewness poles. The earlier assertions that the Hawaiian hotspot has shifted southward relative to the spin axis by 13° since ≈72 Ma are also confirmed. Second, updated reconstructions of the Pacific plate relative to the hotspots for the past 68 million years are presented, with the uncertainties in the reconstructions. Plate-circuit reconstructions are used to predict the tracks of some major Indo-Atlantic hotspots (Tristan da Cunha, Reunion and Iceland) from the Pacific-hotspot plate motion and the rates of relative motion between the Pacific and Indo-Atlantic hotspots are estimated. Within the uncertainties, motion between the hotspots is found insignificant for the past 48 million years. For earlier times, a systematic error in the plate circuit used to make the predictions is inferred and which may be due to unmodeled motion between East and West Antarctica. If the observed discrepancy can be shown to correspond to an error in the plate circuit, the southward motion of the Hawaiian hotspot of 13° since ≈72 Ma can likely be attributed to true polar wander. Building on the above-mentioned work, finally, for the first time, a globally self-consistent model of plate motions relative to the global hotspots for the past 48 million years is presented, and the implications of this model to the question of relative hotspot motion discussed. The provided globally self-consistent set of reconstructions can be used as a fixed frame of reference for absolute plate motions, and true polar wander, ... |
author2 |
Gordon, Richard G. |
format |
Thesis |
author |
Koivisto, Emilia Anna-Liisa |
author_facet |
Koivisto, Emilia Anna-Liisa |
author_sort |
Koivisto, Emilia Anna-Liisa |
title |
Tests of inter-hotspot motion and of hotspot motion relative to the spin axis |
title_short |
Tests of inter-hotspot motion and of hotspot motion relative to the spin axis |
title_full |
Tests of inter-hotspot motion and of hotspot motion relative to the spin axis |
title_fullStr |
Tests of inter-hotspot motion and of hotspot motion relative to the spin axis |
title_full_unstemmed |
Tests of inter-hotspot motion and of hotspot motion relative to the spin axis |
title_sort |
tests of inter-hotspot motion and of hotspot motion relative to the spin axis |
publishDate |
2010 |
url |
https://hdl.handle.net/1911/62159 |
long_lat |
ENVELOPE(140.900,140.900,-66.735,-66.735) |
geographic |
Pacific Tristan West Antarctica |
geographic_facet |
Pacific Tristan West Antarctica |
genre |
Antarc* Antarctica Iceland West Antarctica |
genre_facet |
Antarc* Antarctica Iceland West Antarctica |
op_relation |
Koivisto, Emilia Anna-Liisa. "Tests of inter-hotspot motion and of hotspot motion relative to the spin axis." (2010) Diss., Rice University. https://hdl.handle.net/1911/62159 . https://hdl.handle.net/1911/62159 THESIS GEOL. 2010 KOIVISTO |
_version_ |
1766058867374948352 |