scholarly journals Synergy of Experimental Rock Mechanics, Seismology, and Geodynamics Reveals Still Elusive Upper Mantle Rheology

2020 ◽  
Vol 125 (11) ◽  
Author(s):  
Chhavi Jain ◽  
Jun Korenaga
Keyword(s):  
Rock Mechanics ◽  
Upper Mantle ◽  
Experimental Rock ◽  
Mantle Rheology

scholarly journals Feedbacks between a non-Newtonian upper mantle, mantle viscosity structure and mantle dynamics

2020 ◽  
Vol 224 (2) ◽  
pp. 961-972
Author(s):  
A G Semple ◽  
A Lenardic
Keyword(s):  
Upper Mantle ◽  
Lower Mantle ◽  
Mantle Convection ◽  
Mantle Flow ◽  
Mantle Dynamics ◽  
Plate Motions ◽  
Low Viscosity ◽  
Mantle Viscosity ◽  
Flow Feature ◽  
Mantle Rheology

SUMMARY Previous studies have shown that a low viscosity upper mantle can impact the wavelength of mantle flow and the balance of plate driving to resisting forces. Those studies assumed that mantle viscosity is independent of mantle flow. We explore the potential that mantle flow is not only influenced by viscosity but can also feedback and alter mantle viscosity structure owing to a non-Newtonian upper-mantle rheology. Our results indicate that the average viscosity of the upper mantle, and viscosity variations within it, are affected by the depth to which a non-Newtonian rheology holds. Changes in the wavelength of mantle flow, that occur when upper-mantle viscosity drops below a critical value, alter flow velocities which, in turn, alter mantle viscosity. Those changes also affect flow profiles in the mantle and the degree to which mantle flow drives the motion of a plate analogue above it. Enhanced upper-mantle flow, due to an increasing degree of non-Newtonian behaviour, decreases the ratio of upper- to lower-mantle viscosity. Whole layer mantle convection is maintained but upper- and lower-mantle flow take on different dynamic forms: fast and concentrated upper-mantle flow; slow and diffuse lower-mantle flow. Collectively, mantle viscosity, mantle flow wavelengths, upper- to lower-mantle velocities and the degree to which the mantle can drive plate motions become connected to one another through coupled feedback loops. Under this view of mantle dynamics, depth-variable mantle viscosity is an emergent flow feature that both affects and is affected by the configuration of mantle and plate flow.

Small effect of water on upper-mantle rheology based on silicon self-diffusion coefficients

Nature ◽  
2013 ◽  
Vol 498 (7453) ◽  
pp. 213-215 ◽  
Author(s):  
Hongzhan Fei ◽  
Michael Wiedenbeck ◽  
Daisuke Yamazaki ◽  
Tomoo Katsura
Keyword(s):  
Upper Mantle ◽  
Diffusion Coefficients ◽  
Self Diffusion ◽  
Effect Of Water ◽  
Mantle Rheology

scholarly journals Upper mantle rheology from GRACE and GPS postseismic deformation after the 2004 Sumatra-Andaman earthquake

2010 ◽  
Vol 11 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
I. Panet ◽  
F. Pollitz ◽  
V. Mikhailov ◽  
M. Diament ◽  
P. Banerjee ◽  
...  
Keyword(s):  
Upper Mantle ◽  
Postseismic Deformation ◽  
Mantle Rheology ◽  
Andaman Earthquake

Radial seismic anisotropy as a constraint for upper mantle rheology

2008 ◽  
Vol 267 (1-2) ◽  
pp. 213-227 ◽  
Author(s):  
Thorsten W. Becker ◽  
Bogdan Kustowski ◽  
Göran Ekström
Keyword(s):  
Upper Mantle ◽  
Seismic Anisotropy ◽  
Mantle Rheology

scholarly journals Numerical Modeling of Mantle Flow Beneath Madagascar to Constrain Upper Mantle Rheology Beneath Continental Regions

2020 ◽  
Vol 125 (2) ◽  
Author(s):  
T. A. Rajaonarison ◽  
D. S. Stamps ◽  
S. Fishwick ◽  
S. Brune ◽  
A. Glerum ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Upper Mantle ◽  
Mantle Flow ◽  
Mantle Rheology
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