Convection in the Earth's core driven by lateral variations in the core-mantle boundary heat flux

In the present paper the influence of the initial stress is shown on the reflection and transmission ofPwaves at the core-mantle boundary. Taking a particular value of the inherent initial stress, the variations of reflection and transmission coefficients with respect to the angle of emergence are represented by graphs. These graphs when compared with those having no initial stress show that the effect of the initial stress is to produce a reflectedPandSwaves with numerically higher amplitudes but a transmittedPwave with smaller amplitude. A method is also indicated in this paper to calculate the actual value of the initial stress near the core-mantle boundary by measuring the amplitudes of incident and reflectedPwaves.

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Variation of thermal conductivity and heat flux at the Earth's core mantle boundary

Earth and Planetary Science Letters ◽

10.1016/j.epsl.2014.01.009 ◽

2014 ◽

Vol 390 ◽

pp. 175-185 ◽

Cited By ~ 28

Author(s):

Michael W. Ammann ◽

Andrew M. Walker ◽

Stephen Stackhouse ◽

James Wookey ◽

Alessandro M. Forte ◽

...

Keyword(s):

Thermal Conductivity ◽

Heat Flux ◽

Earth’S Core ◽

Earth's Core ◽

Mantle Boundary ◽

Core Mantle Boundary

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A study of the core-mantle boundary usingPwaves diffracted by the Earth's core

Journal of Geophysical Research Atmospheres ◽

10.1029/jz071i024p05943 ◽

1966 ◽

Vol 71 (24) ◽

pp. 5943-5958 ◽

Cited By ~ 56

Author(s):

Shelton S. Alexander ◽

Robert A. Phinney

Keyword(s):

Earth’S Core ◽

Earth's Core ◽

Mantle Boundary ◽

Core Mantle Boundary ◽

The Core

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Melting of iron–silicon alloy up to the core–mantle boundary pressure: implications to the thermal structure of the Earth’s core

Physics and Chemistry of Minerals ◽

10.1007/s00269-009-0338-7 ◽

2009 ◽

Vol 37 (6) ◽

pp. 353-359 ◽

Cited By ~ 31

Author(s):

Hidetoshi Asanuma ◽

Eiji Ohtani ◽

Takeshi Sakai ◽

Hidenori Terasaki ◽

Seiji Kamada ◽

...

Keyword(s):

Thermal Structure ◽

Earth’S Core ◽

Earth's Core ◽

Silicon Alloy ◽

Mantle Boundary ◽

Core Mantle Boundary ◽

Iron Silicon ◽

The Core

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Thermal conductivity of Fe-Si alloys and thermal stratification in Earth’s core

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2119001119 ◽

2021 ◽

Vol 119 (1) ◽

pp. e2119001119

Author(s):

Youjun Zhang ◽

Kai Luo ◽

Mingqiang Hou ◽

Peter Driscoll ◽

Nilesh P. Salke ◽

...

Keyword(s):

Thermal Conductivity ◽

High Pressure ◽

Transport Properties ◽

Outer Core ◽

Earth’S Core ◽

High Pressure And Temperature ◽

Earth's Core ◽

Mantle Boundary ◽

Core Mantle Boundary ◽

The Core

Light elements in Earth’s core play a key role in driving convection and influencing geodynamics, both of which are crucial to the geodynamo. However, the thermal transport properties of iron alloys at high-pressure and -temperature conditions remain uncertain. Here we investigate the transport properties of solid hexagonal close-packed and liquid Fe-Si alloys with 4.3 and 9.0 wt % Si at high pressure and temperature using laser-heated diamond anvil cell experiments and first-principles molecular dynamics and dynamical mean field theory calculations. In contrast to the case of Fe, Si impurity scattering gradually dominates the total scattering in Fe-Si alloys with increasing Si concentration, leading to temperature independence of the resistivity and less electron–electron contribution to the conductivity in Fe-9Si. Our results show a thermal conductivity of ∼100 to 110 W⋅m−1⋅K−1 for liquid Fe-9Si near the topmost outer core. If Earth’s core consists of a large amount of silicon (e.g., > 4.3 wt %) with such a high thermal conductivity, a subadiabatic heat flow across the core–mantle boundary is likely, leaving a 400- to 500-km-deep thermally stratified layer below the core–mantle boundary, and challenges proposed thermal convection in Fe-Si liquid outer core.

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