Trench-Parallel Flow Beneath the Nazca Plate from Seismic Anisotropy
Shear-wave splitting of S and SKS phases reveals the anisotropy and strain field of the mantle beneath the subducting Nazca plate, Cocos plate, and the Caribbean region. These observations can be used to test models of mantle flow. Two-dimensional entrained mantle flow beneath the subducting Nazca s...
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American Association for the Advancement of Science (AAAS)
1994
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Online Access: | http://dx.doi.org/10.1126/science.263.5150.1105 https://www.science.org/doi/pdf/10.1126/science.263.5150.1105 |
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craaas:10.1126/science.263.5150.1105 2024-06-23T07:56:37+00:00 Trench-Parallel Flow Beneath the Nazca Plate from Seismic Anisotropy Russo, R. M. Silver, P. G. 1994 http://dx.doi.org/10.1126/science.263.5150.1105 https://www.science.org/doi/pdf/10.1126/science.263.5150.1105 en eng American Association for the Advancement of Science (AAAS) Science volume 263, issue 5150, page 1105-1111 ISSN 0036-8075 1095-9203 journal-article 1994 craaas https://doi.org/10.1126/science.263.5150.1105 2024-06-06T04:01:11Z Shear-wave splitting of S and SKS phases reveals the anisotropy and strain field of the mantle beneath the subducting Nazca plate, Cocos plate, and the Caribbean region. These observations can be used to test models of mantle flow. Two-dimensional entrained mantle flow beneath the subducting Nazca slab is not consistent with the data. Rather, there is evidence for horizontal trench-parallel flow in the mantle beneath the Nazca plate along much of the Andean subduction zone. Trench-parallel flow is attributable to retrograde motion of the slab, the decoupling of the slab and underlying mantle, and a partial barrier to flow at depth, resulting in lateral mantle flow beneath the slab. Such flow facilitates the transfer of material from the shrinking mantle reservoir beneath the Pacific basin to the growing mantle reservoir beneath the Atlantic basin. Trench-parallel flow may explain the eastward motions of the Caribbean and Scotia sea plates, the anomalously shallow bathymetry of the eastern Nazca plate, the long-wavelength geoid high over western South America, and it may contribute to the high elevation and intense deformation of the central Andes. Article in Journal/Newspaper Scotia Sea AAAS Resource Center (American Association for the Advancement of Science) Pacific Scotia Sea Science 263 5150 1105 1111 |
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Open Polar |
collection |
AAAS Resource Center (American Association for the Advancement of Science) |
op_collection_id |
craaas |
language |
English |
description |
Shear-wave splitting of S and SKS phases reveals the anisotropy and strain field of the mantle beneath the subducting Nazca plate, Cocos plate, and the Caribbean region. These observations can be used to test models of mantle flow. Two-dimensional entrained mantle flow beneath the subducting Nazca slab is not consistent with the data. Rather, there is evidence for horizontal trench-parallel flow in the mantle beneath the Nazca plate along much of the Andean subduction zone. Trench-parallel flow is attributable to retrograde motion of the slab, the decoupling of the slab and underlying mantle, and a partial barrier to flow at depth, resulting in lateral mantle flow beneath the slab. Such flow facilitates the transfer of material from the shrinking mantle reservoir beneath the Pacific basin to the growing mantle reservoir beneath the Atlantic basin. Trench-parallel flow may explain the eastward motions of the Caribbean and Scotia sea plates, the anomalously shallow bathymetry of the eastern Nazca plate, the long-wavelength geoid high over western South America, and it may contribute to the high elevation and intense deformation of the central Andes. |
format |
Article in Journal/Newspaper |
author |
Russo, R. M. Silver, P. G. |
spellingShingle |
Russo, R. M. Silver, P. G. Trench-Parallel Flow Beneath the Nazca Plate from Seismic Anisotropy |
author_facet |
Russo, R. M. Silver, P. G. |
author_sort |
Russo, R. M. |
title |
Trench-Parallel Flow Beneath the Nazca Plate from Seismic Anisotropy |
title_short |
Trench-Parallel Flow Beneath the Nazca Plate from Seismic Anisotropy |
title_full |
Trench-Parallel Flow Beneath the Nazca Plate from Seismic Anisotropy |
title_fullStr |
Trench-Parallel Flow Beneath the Nazca Plate from Seismic Anisotropy |
title_full_unstemmed |
Trench-Parallel Flow Beneath the Nazca Plate from Seismic Anisotropy |
title_sort |
trench-parallel flow beneath the nazca plate from seismic anisotropy |
publisher |
American Association for the Advancement of Science (AAAS) |
publishDate |
1994 |
url |
http://dx.doi.org/10.1126/science.263.5150.1105 https://www.science.org/doi/pdf/10.1126/science.263.5150.1105 |
geographic |
Pacific Scotia Sea |
geographic_facet |
Pacific Scotia Sea |
genre |
Scotia Sea |
genre_facet |
Scotia Sea |
op_source |
Science volume 263, issue 5150, page 1105-1111 ISSN 0036-8075 1095-9203 |
op_doi |
https://doi.org/10.1126/science.263.5150.1105 |
container_title |
Science |
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263 |
container_issue |
5150 |
container_start_page |
1105 |
op_container_end_page |
1111 |
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1802649885159194624 |