Short wavelength topography on the inner-core boundary
International audience Constraining the topography of the ICB is important for studies of core-mantle coupling and the generation of the geodynamo. We present evidence for significant temporal variability in the amplitude of the inner core reflected phase PKiKP for an exceptionally high quality eart...
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ftunivnantes:oai:HAL:hal-01653919v1 2023-05-15T18:23:34+02:00 Short wavelength topography on the inner-core boundary Cao, Aimin Masson, Yder J. Romanowicz, Barbara Department of Earth and Planetary Science UC Berkeley (EPS) University of California Berkeley (UC Berkeley) University of California (UC)-University of California (UC) Seismological Laboratory Berkeley 2007-01-02 https://hal.archives-ouvertes.fr/hal-01653919 https://hal.archives-ouvertes.fr/hal-01653919/document https://hal.archives-ouvertes.fr/hal-01653919/file/cao_pnas07.pdf https://doi.org/10.1073/pnas.0609810104 en eng HAL CCSD National Academy of Sciences info:eu-repo/semantics/altIdentifier/doi/10.1073/pnas.0609810104 hal-01653919 https://hal.archives-ouvertes.fr/hal-01653919 https://hal.archives-ouvertes.fr/hal-01653919/document https://hal.archives-ouvertes.fr/hal-01653919/file/cao_pnas07.pdf doi:10.1073/pnas.0609810104 info:eu-repo/semantics/OpenAccess ISSN: 0027-8424 EISSN: 1091-6490 Proceedings of the National Academy of Sciences of the United States of America https://hal.archives-ouvertes.fr/hal-01653919 Proceedings of the National Academy of Sciences of the United States of America, 2007, 104 (1), pp.31 - 35. ⟨10.1073/pnas.0609810104⟩ [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] info:eu-repo/semantics/article Journal articles 2007 ftunivnantes https://doi.org/10.1073/pnas.0609810104 2022-11-30T01:54:48Z International audience Constraining the topography of the ICB is important for studies of core-mantle coupling and the generation of the geodynamo. We present evidence for significant temporal variability in the amplitude of the inner core reflected phase PKiKP for an exceptionally high quality earthquake doublet, observed post-critically at the short period Yellowknife seismic array (YK), which occurred in the South Sandwich Islands within a ten year interval (1993/2003). This observation, complemented by data from several other dou-blets, indicates the presence of topography at the inner-core boundary, with a horizontal wavelength on the order of 10 km. Such topography could be sustained by small scale convection at the top of the inner core, and is compatible with a rate of super-rotation of the inner core of ∼0.1-0.15 deg/year. In the absence of inner core rotation, decadal scale temporal changes in the ICB topography would provide an upper bound on the viscosity at the top of the inner core. Inner Core | Topography | PKiKP | Super Rotation Article in Journal/Newspaper South Sandwich Islands Yellowknife Université de Nantes: HAL-UNIV-NANTES Sandwich Islands South Sandwich Islands Yellowknife Proceedings of the National Academy of Sciences 104 1 31 35 |
institution |
Open Polar |
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Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] |
spellingShingle |
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] Cao, Aimin Masson, Yder J. Romanowicz, Barbara Short wavelength topography on the inner-core boundary |
topic_facet |
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] |
description |
International audience Constraining the topography of the ICB is important for studies of core-mantle coupling and the generation of the geodynamo. We present evidence for significant temporal variability in the amplitude of the inner core reflected phase PKiKP for an exceptionally high quality earthquake doublet, observed post-critically at the short period Yellowknife seismic array (YK), which occurred in the South Sandwich Islands within a ten year interval (1993/2003). This observation, complemented by data from several other dou-blets, indicates the presence of topography at the inner-core boundary, with a horizontal wavelength on the order of 10 km. Such topography could be sustained by small scale convection at the top of the inner core, and is compatible with a rate of super-rotation of the inner core of ∼0.1-0.15 deg/year. In the absence of inner core rotation, decadal scale temporal changes in the ICB topography would provide an upper bound on the viscosity at the top of the inner core. Inner Core | Topography | PKiKP | Super Rotation |
author2 |
Department of Earth and Planetary Science UC Berkeley (EPS) University of California Berkeley (UC Berkeley) University of California (UC)-University of California (UC) Seismological Laboratory Berkeley |
format |
Article in Journal/Newspaper |
author |
Cao, Aimin Masson, Yder J. Romanowicz, Barbara |
author_facet |
Cao, Aimin Masson, Yder J. Romanowicz, Barbara |
author_sort |
Cao, Aimin |
title |
Short wavelength topography on the inner-core boundary |
title_short |
Short wavelength topography on the inner-core boundary |
title_full |
Short wavelength topography on the inner-core boundary |
title_fullStr |
Short wavelength topography on the inner-core boundary |
title_full_unstemmed |
Short wavelength topography on the inner-core boundary |
title_sort |
short wavelength topography on the inner-core boundary |
publisher |
HAL CCSD |
publishDate |
2007 |
url |
https://hal.archives-ouvertes.fr/hal-01653919 https://hal.archives-ouvertes.fr/hal-01653919/document https://hal.archives-ouvertes.fr/hal-01653919/file/cao_pnas07.pdf https://doi.org/10.1073/pnas.0609810104 |
geographic |
Sandwich Islands South Sandwich Islands Yellowknife |
geographic_facet |
Sandwich Islands South Sandwich Islands Yellowknife |
genre |
South Sandwich Islands Yellowknife |
genre_facet |
South Sandwich Islands Yellowknife |
op_source |
ISSN: 0027-8424 EISSN: 1091-6490 Proceedings of the National Academy of Sciences of the United States of America https://hal.archives-ouvertes.fr/hal-01653919 Proceedings of the National Academy of Sciences of the United States of America, 2007, 104 (1), pp.31 - 35. ⟨10.1073/pnas.0609810104⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1073/pnas.0609810104 hal-01653919 https://hal.archives-ouvertes.fr/hal-01653919 https://hal.archives-ouvertes.fr/hal-01653919/document https://hal.archives-ouvertes.fr/hal-01653919/file/cao_pnas07.pdf doi:10.1073/pnas.0609810104 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1073/pnas.0609810104 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
104 |
container_issue |
1 |
container_start_page |
31 |
op_container_end_page |
35 |
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1766203586736291840 |