Evidence of High-Shear-Velocity Anomalies Inside the Pacific LLSVP

We present the evidence of high-velocity regions within the Pacific Large Low Seismic Velocity Province (LLSVP), uncovered using the Virtual Receiver Approach (VRA), a novel seismic imaging method that allows us to determine local absolute velocity values of a non-reflecting body wave that are indep...

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Main Authors: Rafael Abreu, Mariano S. Arnaiz-Rodríguez, Chahana Nagesh
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Geosciences
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Online Access:https://www.mdpi.com/2076-3263/15/3/102
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author Rafael Abreu
Mariano S. Arnaiz-Rodríguez
Chahana Nagesh
author_facet Rafael Abreu
Mariano S. Arnaiz-Rodríguez
Chahana Nagesh
author_sort Rafael Abreu
collection DOAJ
description We present the evidence of high-velocity regions within the Pacific Large Low Seismic Velocity Province (LLSVP), uncovered using the Virtual Receiver Approach (VRA), a novel seismic imaging method that allows us to determine local absolute velocity values of a non-reflecting body wave that are independent of any assumed Earth model. Our results reveal a complex dynamics of high- and low-velocity regions within the Pacific LLSVP. While low-shear-wave velocities dominate, consistent with the traditionally understood nature of LLSVPs, we identify distinct high-velocity anomalies—an observation not previously reported in this region. We interpret these anomalies as lateral compositional variations within the LLSVP. Petrological modeling suggests that high-velocity regions are associated with low FeO content, potentially linked to the inclusion of post-perovskite material driven by mantle convection. Alternatively, remnants of subducted oceanic crust (e.g., Mid-Ocean Ridge Basalts) could also explain the observed features. Conversely, low-velocity anomalies correspond to FeO-rich compositions. Our findings highlight the thermochemical heterogeneity of the LLSVP, revealing a more complex internal structure than previously thought. The application of the VRA is able to resolve fine-scale structures that have remained as some of the biggest challenges in global tomographic models.
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spelling doaj-art-b4c087ae0b364d0fbafb5e69a80c1a052025-08-20T03:43:36ZengMDPI AGGeosciences2076-32632025-03-0115310210.3390/geosciences15030102Evidence of High-Shear-Velocity Anomalies Inside the Pacific LLSVPRafael Abreu0Mariano S. Arnaiz-Rodríguez1Chahana Nagesh2Institut de Physique du Globe de Paris, CNRS, Université de Paris, 75005 Paris, FranceInstitut de Physique du Globe de Paris, CNRS, Université de Paris, 75005 Paris, FranceInstitut de Physique du Globe de Paris, CNRS, Université de Paris, 75005 Paris, FranceWe present the evidence of high-velocity regions within the Pacific Large Low Seismic Velocity Province (LLSVP), uncovered using the Virtual Receiver Approach (VRA), a novel seismic imaging method that allows us to determine local absolute velocity values of a non-reflecting body wave that are independent of any assumed Earth model. Our results reveal a complex dynamics of high- and low-velocity regions within the Pacific LLSVP. While low-shear-wave velocities dominate, consistent with the traditionally understood nature of LLSVPs, we identify distinct high-velocity anomalies—an observation not previously reported in this region. We interpret these anomalies as lateral compositional variations within the LLSVP. Petrological modeling suggests that high-velocity regions are associated with low FeO content, potentially linked to the inclusion of post-perovskite material driven by mantle convection. Alternatively, remnants of subducted oceanic crust (e.g., Mid-Ocean Ridge Basalts) could also explain the observed features. Conversely, low-velocity anomalies correspond to FeO-rich compositions. Our findings highlight the thermochemical heterogeneity of the LLSVP, revealing a more complex internal structure than previously thought. The application of the VRA is able to resolve fine-scale structures that have remained as some of the biggest challenges in global tomographic models.https://www.mdpi.com/2076-3263/15/3/102seismic arraysseismic imagingcomposition of the Earth
spellingShingle Rafael Abreu
Mariano S. Arnaiz-Rodríguez
Chahana Nagesh
Evidence of High-Shear-Velocity Anomalies Inside the Pacific LLSVP
Geosciences
seismic arrays
seismic imaging
composition of the Earth
title Evidence of High-Shear-Velocity Anomalies Inside the Pacific LLSVP
title_full Evidence of High-Shear-Velocity Anomalies Inside the Pacific LLSVP
title_fullStr Evidence of High-Shear-Velocity Anomalies Inside the Pacific LLSVP
title_full_unstemmed Evidence of High-Shear-Velocity Anomalies Inside the Pacific LLSVP
title_short Evidence of High-Shear-Velocity Anomalies Inside the Pacific LLSVP
title_sort evidence of high shear velocity anomalies inside the pacific llsvp
topic seismic arrays
seismic imaging
composition of the Earth
url https://www.mdpi.com/2076-3263/15/3/102
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AT marianosarnaizrodriguez evidenceofhighshearvelocityanomaliesinsidethepacificllsvp
AT chahananagesh evidenceofhighshearvelocityanomaliesinsidethepacificllsvp