Modeling Anisotropic Signature of Slab‐Induced Mantle Plumes From Thermochemical Piles in the Lowermost Mantle

Abstract Seismic anisotropy, observed in the lowermost mantle near Large Low‐Shear‐Velocity Provinces (LLSVPs), is likely caused by strong deformation from mantle flow interacting with these regions and/or plume formation. This study explores slab‐induced plume generation from LLSVPs under the assum...

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Main Authors: Poulami Roy, Bernhard Steinberger, Manuele Faccenda, Michaël Pons
Format: Article
Language:English
Published: Wiley 2025-05-01
Series:Geophysical Research Letters
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Online Access:https://doi.org/10.1029/2024GL113299
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author Poulami Roy
Bernhard Steinberger
Manuele Faccenda
Michaël Pons
author_facet Poulami Roy
Bernhard Steinberger
Manuele Faccenda
Michaël Pons
author_sort Poulami Roy
collection DOAJ
description Abstract Seismic anisotropy, observed in the lowermost mantle near Large Low‐Shear‐Velocity Provinces (LLSVPs), is likely caused by strong deformation from mantle flow interacting with these regions and/or plume formation. This study explores slab‐induced plume generation from LLSVPs under the assumption that LLSVPs are thermochemical piles and resulting flow behavior using 3‐D regional‐scale mantle convection models in ASPECT, coupled with mantle fabric simulations in ECOMAN. We tested various models with different LLSVP density and viscosity. The modeling of the crystallographic‐preferred orientation with predominant activity of the slip system [001](100) for Bridgmanite and [100](001) for post‐Perovskite reveals that substantial seismic anisotropy develops in the lowermost mantle, and specifically (a) at the margins of the rheologically stiffer LLSVP piles where deformation and upwelling of the surrounding mantle take place and fast horizontally polarized shear waves (Vsh) transition to fast Vsv and (b) within plume roots and conduits where vertically polarized shear waves (Vsv) are faster.
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spelling doaj-art-3c3157c4b05e46d19889b0ff4fcd659d2025-08-20T03:10:31ZengWileyGeophysical Research Letters0094-82761944-80072025-05-015210n/an/a10.1029/2024GL113299Modeling Anisotropic Signature of Slab‐Induced Mantle Plumes From Thermochemical Piles in the Lowermost MantlePoulami Roy0Bernhard Steinberger1Manuele Faccenda2Michaël Pons3GFZ Helmholtz Centre for Geosciences Potsdam GermanyGFZ Helmholtz Centre for Geosciences Potsdam GermanyDipartimento di Geoscienze Università degli Studi di Padova Padova ItalyGFZ Helmholtz Centre for Geosciences Potsdam GermanyAbstract Seismic anisotropy, observed in the lowermost mantle near Large Low‐Shear‐Velocity Provinces (LLSVPs), is likely caused by strong deformation from mantle flow interacting with these regions and/or plume formation. This study explores slab‐induced plume generation from LLSVPs under the assumption that LLSVPs are thermochemical piles and resulting flow behavior using 3‐D regional‐scale mantle convection models in ASPECT, coupled with mantle fabric simulations in ECOMAN. We tested various models with different LLSVP density and viscosity. The modeling of the crystallographic‐preferred orientation with predominant activity of the slip system [001](100) for Bridgmanite and [100](001) for post‐Perovskite reveals that substantial seismic anisotropy develops in the lowermost mantle, and specifically (a) at the margins of the rheologically stiffer LLSVP piles where deformation and upwelling of the surrounding mantle take place and fast horizontally polarized shear waves (Vsh) transition to fast Vsv and (b) within plume roots and conduits where vertically polarized shear waves (Vsv) are faster.https://doi.org/10.1029/2024GL113299lower mantleradial anisotropyslabmantle plumesthermochemical plumesthermochemical piles
spellingShingle Poulami Roy
Bernhard Steinberger
Manuele Faccenda
Michaël Pons
Modeling Anisotropic Signature of Slab‐Induced Mantle Plumes From Thermochemical Piles in the Lowermost Mantle
Geophysical Research Letters
lower mantle
radial anisotropy
slab
mantle plumes
thermochemical plumes
thermochemical piles
title Modeling Anisotropic Signature of Slab‐Induced Mantle Plumes From Thermochemical Piles in the Lowermost Mantle
title_full Modeling Anisotropic Signature of Slab‐Induced Mantle Plumes From Thermochemical Piles in the Lowermost Mantle
title_fullStr Modeling Anisotropic Signature of Slab‐Induced Mantle Plumes From Thermochemical Piles in the Lowermost Mantle
title_full_unstemmed Modeling Anisotropic Signature of Slab‐Induced Mantle Plumes From Thermochemical Piles in the Lowermost Mantle
title_short Modeling Anisotropic Signature of Slab‐Induced Mantle Plumes From Thermochemical Piles in the Lowermost Mantle
title_sort modeling anisotropic signature of slab induced mantle plumes from thermochemical piles in the lowermost mantle
topic lower mantle
radial anisotropy
slab
mantle plumes
thermochemical plumes
thermochemical piles
url https://doi.org/10.1029/2024GL113299
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AT manuelefaccenda modelinganisotropicsignatureofslabinducedmantleplumesfromthermochemicalpilesinthelowermostmantle
AT michaelpons modelinganisotropicsignatureofslabinducedmantleplumesfromthermochemicalpilesinthelowermostmantle