The impact of variability in the rheological activation parameters onlower-mantle viscosity stratification and its dynamics

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F11%3A10105458" target="_blank" >RIV/00216208:11320/11:10105458 - isvavai.cz</a>
Result on the web
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DOI - Digital Object Identifier
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Result language
angličtina
Original language name
The impact of variability in the rheological activation parameters onlower-mantle viscosity stratification and its dynamics
Original language description
The recently discovered spin-state crossover in iron in major mantleminerals at high pressures should exert dramatic influences on transport properties, such as the activation creep parameters in the deep mantle. Wentzcovitch et al. (2009) have computedthe elastic parameter of ferropericlase that is affected by this crossover, the bulk modulus, at high realistic conditions, using first principles density functional theory plus Hubbard U. As a consequence of the spin crossover there is a significant softening of the bulk modulus and an attendant reduction of the activation energy in the creep law. Using a parameterized model capturing the basic physics, we have studied the dynamical consequences within the framework of a 2-D Cartesian convection model.Our models reveal a series of asthenospheres and are characterized first by a low-viscosity channel below the 670 km boundary (''second asthenosphere'') caused by an increase of temperature and decrease in grain size reduction (superplas
Czech name
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Czech description
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Type
J<sub>x</sub> - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP classification
DE - Earth magnetism, geodesy, geography
OECD FORD branch
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Project
<a href="/en/project/GAP210%2F11%2F1366" target="_blank" >GAP210/11/1366: Transport Properties and Dynamics of the Earth's Lower Mantle</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>Z - Vyzkumny zamer (s odkazem do CEZ)

Publication year
2011
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

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