Imperial College London

Saskia Goes

Faculty of EngineeringDepartment of Earth Science & Engineering

Professor of Geophysics
 
 
 
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Contact

 

+44 (0)20 7594 6434s.goes

 
 
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Location

 

4.47Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Maguire:2017:10.1002/2017GL073120,
author = {Maguire, R and Ritsema, J and Goes, S},
doi = {10.1002/2017GL073120},
journal = {Geophysical Research Letters},
pages = {3600--3607},
title = {Signals of 660-km topography and harzburgite enrichment in seismic images of whole-mantle upwellings},
url = {http://dx.doi.org/10.1002/2017GL073120},
volume = {44},
year = {2017}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - Various changes in seismic structures across the mantle transition zone (MTZ) indicate that it may hamper thermal and chemical circulation. Here we show how thermal elevation of the postspinel phase transition at 660 km depth plus harzburgite segregation below this depth can project as narrow high-velocity anomalies in tomographic images of continuous thermochemical mantle upwellings. Model S40RTS features a narrow high-velocity anomaly of +0.8% near 660 km depth within the broad low-velocity structure beneath the Samoa hot spot. Our analyses indicate that elevation of the 660 phase boundary in a hot pyrolitic plume alone is insufficient to explain this anomaly. An additional effect of harzburgite enrichment is required and consistent with geodynamic simulations that predict compositional segregation in the MTZ, especially within thermochemical upwellings. The Samoa anomaly can be modeled with a 125–175°C excess temperature and a harzburgite enrichment below 660 of least 60% compared to a pyrolitic mantle.
AU - Maguire,R
AU - Ritsema,J
AU - Goes,S
DO - 10.1002/2017GL073120
EP - 3607
PY - 2017///
SN - 1944-8007
SP - 3600
TI - Signals of 660-km topography and harzburgite enrichment in seismic images of whole-mantle upwellings
T2 - Geophysical Research Letters
UR - http://dx.doi.org/10.1002/2017GL073120
UR - http://hdl.handle.net/10044/1/46257
VL - 44
ER -