Results 1 to 10 of about 753 (148)
Antarctic upper mantle rheology
Geological Society, London, Memoirs, 2021 Abstract The Antarctic mantle and lithosphere are known to have large lateral contrasts in seismic velocity and tectonic history. These contrasts suggest differences in the response timescale of mantle flow across the continent, similar to those documented between the northeastern and southwestern upper mantle of North America.
E. R. Ivins +4 more
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Arrhenius rheology versus Frank‐Kamenetskii rheology—Implications for mantle dynamics [PDF]
Geochemistry, Geophysics, Geosystems, 2013 The viscosity of planetary mantle material is strongly temperature dependent. This dependence is described by an Arrhenius law. But for the realistic viscosity contrast that appears over the depth of the mantle, strong gradients in the upper thermal boundary layer occur. These strong gradients are not realizable in numerical models.
C. Stein, U. Hansen
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Eos, Transactions American Geophysical Union, 1971 There have been two main avenues of investigation of the rheology of the mantle: theoretical and laboratory studies of the mechanical behavior of solids and direct estimates obtained by comparing geologic observations with model calculations in which rheological parameters are the principal variables.
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Narrow, fast, and "cool" mantle plumes caused by strain-weakening rheology in Earth's lower mantle
Geochemistry, Geophysics, Geosystems, 2022 The rheological properties of Earth's lower mantle are key for mantle dynamics and planetary evolution. The main rock-forming minerals in the lower mantle are bridgmanite (Br) and smaller amounts of ferropericlase (Fp). Previous work has suggested that the large differences in viscosity between these minerals greatly affect the bulk rock rheology.
A. J. P. Gülcher +4 more
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Shallow upper mantle rheology and secular ice sheet fluctuations [PDF]
Tectonophysics, 2011 On time scales from decades to centuries, continental cryospheric forcing in response to climate change constitutes a major source of isostatic disequilibrium that may influence future regional sea level variations. Current vertical displacements and gravity field variations are often estimated neglecting rheological effects and thus assuming a fully ...
Spada, G., F. Colleoni, and G. Ruggieri
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Ferropericlase Control of Lower Mantle Rheology: Impact of Phase Morphology [PDF]
Geochemistry, Geophysics, Geosystems, 2020 AbstractThe rheological properties of Earth's lower mantle play a key role for global mantle dynamics. The mineralogy of the lower mantle can be approximated as a bridgmanite‐ferropericlase mixture. Previous work has suggested that the deformation of this mixture might be dramatically affected by the large differences in viscosity between bridgmanite ...
M. Thielmann +2 more
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Numerical Modeling of Mantle Flow Beneath Madagascar to Constrain Upper Mantle Rheology Beneath Continental Regions [PDF]
Journal of Geophysical Research: Solid Earth, 2020 AbstractOver the past few decades, azimuthal seismic anisotropy measurements have been widely used proxy to study past and present‐day deformation of the lithosphere and to characterize convection in the mantle. Beneath continental regions, distinguishing between shallow and deep sources of anisotropy remains difficult due to poor depth constraints of ...
Rajaonarison, T. +5 more
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Post-glacial rebound and transient lower mantle rheology [PDF]
Geophysical Journal International, 1986 Summary. Although post-glacial rebound data have been conventionally interpreted as being governed by the steady state component of the mantle viscosity spectrum, the radial profile of this parameter, which is then inferred by fitting a model to observations, is characterized by the fact that it exhibits rather slight variation with depth.
W. R. Peltier +2 more
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Is the lower‐mantle rheology Newtonian today?
Geophysical Research Letters, 1996 The issue concerning the dominant creep mechanism in mantle convection has been studied numerically with a rheology incorporating both linear and non‐linear elements. We have employed a rheology suggested by the recently obtained melting temperature of lower‐mantle constituents. For an effective Rayleigh number between 105 and 106 this type of strongly
Arie P. van den Berg, David A. Yuen
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Sea‐level fluctuations due to subduction: The role of mantle rheology [PDF]
Geophysical Research Letters, 1997 By means of a stratified viscoelastic Earth model we study the effect of sinking slabs on the dynamic topography, the non‐hydrostatic geoid and the long‐term sea level variations. Sea level fluctuations due to subduction are found to be sensitive to the nature of the 670 km seismic discontinuity and to the rheological layering of the mantle.
C. PIROMALLO +3 more
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