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Kinematics and dynamics of the East Pacific Rise linked to a stable, deep-mantle upwelling
Earth’s tectonic plates are generally considered to be driven largely by negative buoyancy associated with subduction of oceanic lithosphere. In this context, mid-ocean ridges (MORs) are passive plate boundaries whose divergence accommodates flow driven by subduction of oceanic slabs at trenches. We...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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American Association for the Advancement of Science
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5182052/ https://www.ncbi.nlm.nih.gov/pubmed/28028535 http://dx.doi.org/10.1126/sciadv.1601107 |
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author | Rowley, David B. Forte, Alessandro M. Rowan, Christopher J. Glišović, Petar Moucha, Robert Grand, Stephen P. Simmons, Nathan A. |
author_facet | Rowley, David B. Forte, Alessandro M. Rowan, Christopher J. Glišović, Petar Moucha, Robert Grand, Stephen P. Simmons, Nathan A. |
author_sort | Rowley, David B. |
collection | PubMed |
description | Earth’s tectonic plates are generally considered to be driven largely by negative buoyancy associated with subduction of oceanic lithosphere. In this context, mid-ocean ridges (MORs) are passive plate boundaries whose divergence accommodates flow driven by subduction of oceanic slabs at trenches. We show that over the past 80 million years (My), the East Pacific Rise (EPR), Earth’s dominant MOR, has been characterized by limited ridge-perpendicular migration and persistent, asymmetric ridge accretion that are anomalous relative to other MORs. We reconstruct the subduction-related buoyancy fluxes of plates on either side of the EPR. The general expectation is that greater slab pull should correlate with faster plate motion and faster spreading at the EPR. Moreover, asymmetry in slab pull on either side of the EPR should correlate with either ridge migration or enhanced plate velocity in the direction of greater slab pull. Based on our analysis, none of the expected correlations are evident. This implies that other forces significantly contribute to EPR behavior. We explain these observations using mantle flow calculations based on globally integrated buoyancy distributions that require core-mantle boundary heat flux of up to 20 TW. The time-dependent mantle flow predictions yield a long-lived deep-seated upwelling that has its highest radial velocity under the EPR and is inferred to control its observed kinematics. The mantle-wide upwelling beneath the EPR drives horizontal components of asthenospheric flows beneath the plates that are similarly asymmetric but faster than the overlying surface plates, thereby contributing to plate motions through viscous tractions in the Pacific region. |
format | Online Article Text |
id | pubmed-5182052 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | American Association for the Advancement of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-51820522016-12-27 Kinematics and dynamics of the East Pacific Rise linked to a stable, deep-mantle upwelling Rowley, David B. Forte, Alessandro M. Rowan, Christopher J. Glišović, Petar Moucha, Robert Grand, Stephen P. Simmons, Nathan A. Sci Adv Research Articles Earth’s tectonic plates are generally considered to be driven largely by negative buoyancy associated with subduction of oceanic lithosphere. In this context, mid-ocean ridges (MORs) are passive plate boundaries whose divergence accommodates flow driven by subduction of oceanic slabs at trenches. We show that over the past 80 million years (My), the East Pacific Rise (EPR), Earth’s dominant MOR, has been characterized by limited ridge-perpendicular migration and persistent, asymmetric ridge accretion that are anomalous relative to other MORs. We reconstruct the subduction-related buoyancy fluxes of plates on either side of the EPR. The general expectation is that greater slab pull should correlate with faster plate motion and faster spreading at the EPR. Moreover, asymmetry in slab pull on either side of the EPR should correlate with either ridge migration or enhanced plate velocity in the direction of greater slab pull. Based on our analysis, none of the expected correlations are evident. This implies that other forces significantly contribute to EPR behavior. We explain these observations using mantle flow calculations based on globally integrated buoyancy distributions that require core-mantle boundary heat flux of up to 20 TW. The time-dependent mantle flow predictions yield a long-lived deep-seated upwelling that has its highest radial velocity under the EPR and is inferred to control its observed kinematics. The mantle-wide upwelling beneath the EPR drives horizontal components of asthenospheric flows beneath the plates that are similarly asymmetric but faster than the overlying surface plates, thereby contributing to plate motions through viscous tractions in the Pacific region. American Association for the Advancement of Science 2016-12-23 /pmc/articles/PMC5182052/ /pubmed/28028535 http://dx.doi.org/10.1126/sciadv.1601107 Text en Copyright © 2016, The Authors http://creativecommons.org/licenses/by-nc/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license (http://creativecommons.org/licenses/by-nc/4.0/) , which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited. |
spellingShingle | Research Articles Rowley, David B. Forte, Alessandro M. Rowan, Christopher J. Glišović, Petar Moucha, Robert Grand, Stephen P. Simmons, Nathan A. Kinematics and dynamics of the East Pacific Rise linked to a stable, deep-mantle upwelling |
title | Kinematics and dynamics of the East Pacific Rise linked to a stable, deep-mantle upwelling |
title_full | Kinematics and dynamics of the East Pacific Rise linked to a stable, deep-mantle upwelling |
title_fullStr | Kinematics and dynamics of the East Pacific Rise linked to a stable, deep-mantle upwelling |
title_full_unstemmed | Kinematics and dynamics of the East Pacific Rise linked to a stable, deep-mantle upwelling |
title_short | Kinematics and dynamics of the East Pacific Rise linked to a stable, deep-mantle upwelling |
title_sort | kinematics and dynamics of the east pacific rise linked to a stable, deep-mantle upwelling |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5182052/ https://www.ncbi.nlm.nih.gov/pubmed/28028535 http://dx.doi.org/10.1126/sciadv.1601107 |
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