Seismic evidence for a plume-modified oceanic lithosphere–asthenosphere system beneath Cape Verde

SUMMARY We determine a new 3-D shear wave velocity (Vs) model down to 400 km depth beneath the Cape Verde hotspot that is far from plate boundaries. This Vs model is obtained by using a new method of jointly inverting P- and S-wave receiver functions, Rayleigh-wave phase-velocity data and S-wave arr...

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Bibliographic Details
Published in:Geophysical journal international Vol. 225; no. 2; pp. 872 - 886
Main Authors: Liu, Xin, Zhao, Dapeng
Format: Journal Article
Language:English
Published: Oxford University Press 01.05.2021
Subjects:
Surface waves and free oscillations
Body waves
Joint inversion
Seismic tomography
Hotspots
Dynamics of lithosphere and mantle
ISSN:0956-540X, 1365-246X
Online Access:Get full text
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Summary:SUMMARY We determine a new 3-D shear wave velocity (Vs) model down to 400 km depth beneath the Cape Verde hotspot that is far from plate boundaries. This Vs model is obtained by using a new method of jointly inverting P- and S-wave receiver functions, Rayleigh-wave phase-velocity data and S-wave arrival times of teleseismic events. Two Vs discontinuities at ∼15 and ∼60 km depths are revealed beneath volcanic islands, which are interpreted as the Moho discontinuity and the Gutenberg (G) discontinuity. Between the north and south islands, obvious high-Vs anomalies exist in the uppermost mantle down to a depth of ∼100–150 km beneath the Atlantic Ocean, whereas obvious low-Vs anomalies exist in the uppermost mantle beneath the volcanic islands including the active Fogo volcano. These low-Vs anomalies merge into a significant column-like low-Vs zone at depths of ∼150–400 km beneath the Cape Verde swell. We propose that these features in the upper mantle reflect a plume-modified oceanic lithosphere–asthenosphere system beneath the Cape Verde hotspot.
ISSN:0956-540X
1365-246X
DOI:10.1093/gji/ggab012