The root to the Galápagos mantle plume on the core-mantle boundary
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 Ultra-low velocity zones (ULVZs) are thin anomalous patches on the boundary between the Earth's core and mantle, revealed by their effects on the seismic waves that propagate through them. Here we map a broad ULVZ near the Galápagos hotspot using shear-diffracted waves....
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ftunivcam:oai:www.repository.cam.ac.uk:1810/343513 2024-01-28T10:06:43+01:00 The root to the Galápagos mantle plume on the core-mantle boundary Cottaar, Sanne Martin, Carl Li, Zhi Parai, Rita 2022-11-19T09:25:19Z application/pdf https://www.repository.cam.ac.uk/handle/1810/343513 https://doi.org/10.17863/CAM.90937 eng eng McGill University Library and Archives Department of Earth Sciences http://dx.doi.org/10.26443/seismica.v1i1.197 Seismica https://www.repository.cam.ac.uk/handle/1810/343513 doi:10.17863/CAM.90937 Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ 37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics Article 2022 ftunivcam https://doi.org/10.17863/CAM.90937 2024-01-04T23:20:00Z <jats:p>
 Ultra-low velocity zones (ULVZs) are thin anomalous patches on the boundary between the Earth's core and mantle, revealed by their effects on the seismic waves that propagate through them. Here we map a broad ULVZ near the Galápagos hotspot using shear-diffracted waves. Forward modelling assuming a cylindrical shape shows the patch is ~600 km wide, ~20 km high, and its shear velocities are ~25% reduced. The ULVZ is comparable to other broad ULVZs mapped on the core-mantle boundary near Hawaii, Iceland, and Samoa. Strikingly, all four hotspots where the mantle plume appears rooted by these ‘mega-ULVZs’, show similar anomalous isotopic signatures in He, Ne, and W in their ocean island basalts. This correlation suggests mega-ULVZs might be primordial or caused by interaction with the core, and some material from ULVZs is entrained within the plume. For the Galápagos, the connection implies the plume is offset to the west towards the base of the mantle. 
 </jats:p> Article in Journal/Newspaper Iceland Ocean Island Apollo - University of Cambridge Repository |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics |
spellingShingle |
37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics Cottaar, Sanne Martin, Carl Li, Zhi Parai, Rita The root to the Galápagos mantle plume on the core-mantle boundary |
topic_facet |
37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics |
description |
<jats:p>
 Ultra-low velocity zones (ULVZs) are thin anomalous patches on the boundary between the Earth's core and mantle, revealed by their effects on the seismic waves that propagate through them. Here we map a broad ULVZ near the Galápagos hotspot using shear-diffracted waves. Forward modelling assuming a cylindrical shape shows the patch is ~600 km wide, ~20 km high, and its shear velocities are ~25% reduced. The ULVZ is comparable to other broad ULVZs mapped on the core-mantle boundary near Hawaii, Iceland, and Samoa. Strikingly, all four hotspots where the mantle plume appears rooted by these ‘mega-ULVZs’, show similar anomalous isotopic signatures in He, Ne, and W in their ocean island basalts. This correlation suggests mega-ULVZs might be primordial or caused by interaction with the core, and some material from ULVZs is entrained within the plume. For the Galápagos, the connection implies the plume is offset to the west towards the base of the mantle. 
 </jats:p> |
format |
Article in Journal/Newspaper |
author |
Cottaar, Sanne Martin, Carl Li, Zhi Parai, Rita |
author_facet |
Cottaar, Sanne Martin, Carl Li, Zhi Parai, Rita |
author_sort |
Cottaar, Sanne |
title |
The root to the Galápagos mantle plume on the core-mantle boundary |
title_short |
The root to the Galápagos mantle plume on the core-mantle boundary |
title_full |
The root to the Galápagos mantle plume on the core-mantle boundary |
title_fullStr |
The root to the Galápagos mantle plume on the core-mantle boundary |
title_full_unstemmed |
The root to the Galápagos mantle plume on the core-mantle boundary |
title_sort |
root to the galápagos mantle plume on the core-mantle boundary |
publisher |
McGill University Library and Archives |
publishDate |
2022 |
url |
https://www.repository.cam.ac.uk/handle/1810/343513 https://doi.org/10.17863/CAM.90937 |
genre |
Iceland Ocean Island |
genre_facet |
Iceland Ocean Island |
op_relation |
https://www.repository.cam.ac.uk/handle/1810/343513 doi:10.17863/CAM.90937 |
op_rights |
Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.17863/CAM.90937 |
_version_ |
1789333784871567360 |