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Journal Articles Journal of Geophysical Research Year : 1993

A geodynamic model of mantle density heterogeneity

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Y. Ricard
M. Richards
  • Function : Author
Y. Le Stunff
  • Function : Author

Abstract

Using Cenozoic and Mesozoic plate motion reconstructions, a model of present-day mantle density heterogeneity is derived under the assumption that subducted slabs sink vertically into the mantle. The thermal buoyancy of these slabs is estimated from the observed thermal subsidence (cooling) of oceanic lithosphere. For a viscosity increase of about a factor of 40 from the upper to lower mantle, our model predicts the first eight spherical harmonic degrees of the geoid with statistical confidence larger than 95% and explains 84% of the observed geoid assuming that the model C21 and S21 terms are absent due to a long relaxation time for Earth's rotational bulge. Otherwise, 73% of the geoid variance is explained. The results show that the history of plate tectonics can explain the main features of the present-day structure of the mantle. -from Authors
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hal-02046765 , version 1 (03-02-2021)

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Y. Ricard, M. Richards, C. Lithgow-Bertelloni, Y. Le Stunff. A geodynamic model of mantle density heterogeneity. Journal of Geophysical Research, 1993, 98 (B12), pp.21,895-21,909. ⟨10.1029/93JB02216⟩. ⟨hal-02046765⟩
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